Aruba JG632A HPE DataCenter Switch User Guide
Reklama
Reklama
HPE FlexFabric 12900E Switch Series
IP Routing Configuration Guide
Software version: Release 5112
Document version: 6W100-20220610
© Copyright 2022 Hewlett Packard Enterprise Development LP
The information contained herein is subject to change without notice. The only warranties for Hewlett Packard
Enterprise products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. Hewlett
Packard Enterprise shall not be liable for technical or editorial errors or omissions contained herein.
Confidential computer software. Valid license from Hewlett Packard Enterprise required for possession, use, or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software
Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor’s standard commercial license.
Links to third-party websites take you outside the Hewlett Packard Enterprise website. Hewlett Packard
Enterprise has no control over and is not responsible for information outside the Hewlett Packard Enterprise website.
Acknowledgments
Intel®, Itanium®, Pentium®, Intel Inside®, and the Intel Inside logo are trademarks of Intel Corporation in the
United States and other countries.
Microsoft® and Windows® are either registered trademarks or trademarks of Microsoft Corporation in the
United States and/or other countries.
Adobe® and Acrobat® are trademarks of Adobe Systems Incorporated.
Java and Oracle are registered trademarks of Oracle and/or its affiliates.
UNIX® is a registered trademark of The Open Group.
Contents
Configuring basic IP routing ··········································································· 1
Configuring static routing ············································································· 17
i
Configuring a default route ··········································································· 33
Configuring RIP ··························································································· 34
ii
Configuring OSPF························································································ 79
iii
iv
Configuring IS-IS ······················································································· 160
v
vi
BGP overview ···························································································· 260
Building basic BGP networks ····································································· 275
vii
Configuring large-scale BGP networks ······················································ 344
Controlling BGP path selection ·································································· 363
viii
Tuning and optimizing BGP networks ························································ 387
Configuring BGP security features ····························································· 415
ix
Improving BGP network reliability ······························································ 430
Configuring extended BGP features ·························································· 454
Configuring PBR ························································································ 470
x
Configuring IPv6 static routing ··································································· 483
Configuring an IPv6 default route······························································· 493
Configuring RIPng ····················································································· 494
xi
Configuring OSPFv3 ·················································································· 517
xii
Configuring IPv6 PBR ················································································ 576
xiii
Configuring routing policies ········································································ 587
Configuring DCN ······················································································· 605
Document conventions and icons ······························································ 616
Support and other resources ····································································· 618
xiv
Index ·········································································································· 621
xv
Configuring basic IP routing
About IP routing
IP routing directs IP packet forwarding on routers. Based on the destination IP address in the packet, a router looks up a route for the packet in a routing table and forwards the packet to the next hop.
Routes are path information used to direct IP packets.
Routing table
A RIB contains the global routing information and related information, including route recursion, route redistribution, and route extension information. The router selects optimal routes from the routing table and puts them into the FIB table. It uses the FIB table to forward packets. For more information about the FIB table, see Layer 3—IP Services Configuration Guide .
Route categories
Table 1 categorizes routes by different criteria.
Table 1 Route categories
Criterion
Origin
Destination
Categories
•
Direct route —A direct route is discovered by the data link protocol on an interface, and is also called an interface route.
•
Static route —A static route is manually configured by an administrator.
•
Dynamic route —A dynamic route is dynamically discovered by a routing protocol.
•
Network route —The destination is a network. The subnet mask is less than 32 bits.
•
Host route —The destination is a host. The subnet mask is 32 bits.
Whether the destination is directly connected
•
Direct route —The destination is directly connected.
•
Indirect route —The destination is indirectly connected.
Dynamic routing protocols
Static routes work well in small, stable networks. They are easy to configure and require fewer system resources. However, in networks where topology changes occur frequently, a typical practice is to configure a dynamic routing protocol. Compared with static routing, a dynamic routing protocol is complicated to configure, requires more router resources, and consumes more network resources.
Dynamic routing protocols dynamically collect and report reachability information to adapt to topology changes. They are suitable for large networks.
Dynamic routing protocols can be classified by different criteria, as shown in Table 2 .
Table 2 Categories of dynamic routing protocols
Criterion
Operation scope
Categories
•
IGPs —Work within an AS. Examples include RIP, OSPF, and IS-IS.
•
EGPs —Work between ASs. The most popular EGP is BGP.
1
Criterion
Routing algorithm
Categories
•
Distance-vector protocols —Examples include RIP and BGP. BGP is also considered a path-vector protocol.
•
Link-state protocols —Examples include OSPF and IS-IS.
Destination address type
Unicast routing protocols —Examples include RIP, OSPF, BGP, and IS-IS.
IP version
•
IPv4 routing protocols —Examples include RIP, OSPF, BGP, and IS-IS.
•
IPv6 routing protocols —Examples include RIPng, OSPFv3, IPv6 BGP, and
IPv6 IS-IS.
An AS refers to a group of routers that use the same routing policy and work under the same administration.
Route preference
Routing protocols, including static and direct routing, each by default have a preference. If they find multiple routes to the same destination, the router selects the route with the highest preference as the optimal route.
The preference of a direct route is always 0 and cannot be changed. You can configure a preference for each static route and each dynamic routing protocol. The following table lists the route types and default preferences. The smaller the value, the higher the preference.
Table 3 Route types and default route preferences
Route type
Direct route
OSPF
IS-IS
Unicast static route
RIP
OSPF ASE
OSPF NSSA
IBGP
EBGP
Unknown (route from an untrusted source)
Preference
0
10
15
60
100
150
150
255
255
256
Load sharing
A routing protocol might find multiple optimal equal-cost routes to the same destination. You can use these routes to implement equal-cost multi-path (ECMP) load sharing.
Static routing, IPv6 static routing, RIP, RIPng, OSPF, OSPFv3, BGP, IPv6 BGP, IS-IS, and IPv6 IS-IS support ECMP load sharing.
2
Route backup
Route backup can improve network availability. Among multiple routes to the same destination, the route with the highest priority is the primary route and others are secondary routes.
The router forwards matching packets through the primary route. When the primary route fails, the route with the highest preference among the secondary routes is selected to forward packets. When the primary route recovers, the router uses it to forward packets.
Route recursion
To use a BGP, static, or RIP route that has an indirectly connected next hop, a router must perform route recursion to find the output interface to reach the next hop.
Link-state routing protocols, such as OSPF and IS-IS, do not need route recursion, because they obtain directly connected next hops through route calculation.
The RIB records and saves route recursion information, including brief information about related routes, recursive paths, and recursion depth.
Route redistribution
Route redistribution enables routing protocols to learn routing information from each other. A dynamic routing protocol can redistribute routes from other routing protocols, including direct and static routing. For more information, see the respective chapters on those routing protocols in this configuration guide.
The RIB records redistribution relationships of routing protocols.
Extension attribute redistribution
Extension attribute redistribution enables routing protocols to learn route extension attributes from each other, including BGP extended community attributes, OSPF area IDs, route types, and router
IDs.
The RIB records extended attributes of each routing protocol and redistribution relationships of different routing protocol extended attributes.
Configuring load sharing
Configuring load sharing mode
About this task
Load sharing can be implemented on a per-flow basis.
In the per-flow load sharing mode, the device forwards flows over equal-cost routes. Packets of one flow travel along the same routes. You can configure the device to identify a flow based on the following criteria: source IP address, destination IP address, source port number, destination port number, and IP protocol number.
In a complex network, when the criteria cannot distinguish flows, you can use the algorithm keyword to specify an algorithm to identify flows.
Procedure
1. Enter system view.
3
system view
2. Configure load sharing. ip load-sharing mode per-flow [ [ level level-number ] algorithm
algorithm-number [ seed seed-number ] [ shift shift-number ] | [ dest-ip
| dest-port | ip-pro | src-ip | src-port ] * ] { global | slot slot-number }
By default, the device performs per-flow load sharing based on the following criteria: source IP address, destination IP address, source port number, destination port number, and IP protocol number.
Enabling IPv4 bandwidth-based load sharing
About this task
This feature load shares flow traffic among multiple output interfaces based on their load percentages. The device calculates the load percentage for each output interface in terms of the interface expected bandwidth.
Devices that run load sharing protocols, such as Locator/ID Separation Protocol (LISP), implement load sharing based on the ratios defined by these protocols.
Restrictions and guidelines
By default, the bandwidth of a VLAN interface is 10 Gbps. If this feature load shares traffic among a
VLAN interface and other type of high-speed output interfaces, only a small portion of packets will be distributed to the VLAN interface. You can increase the bandwidth of the VLAN interface for this feature to distribute more packets to the VLAN interface.
Procedure
1. Enter system view. system view
2. Enable IPv4 bandwidth-based load sharing. bandwidth-based-sharing
By default, the IPv4 bandwidth-based load sharing is disabled.
3. (Optional.) Configure the expected bandwidth of the interface. a. Enter interface view. interface interface-type interface-number b. Configure the expected bandwidth of the interface. bandwidth bandwidth
By default, the expected bandwidth is the physical bandwidth of the interface.
Enabling symmetric load sharing
About this task
Symmetric load sharing ensures that bidirectional traffic specific to a source and destination address pair flow along the same path.
Procedure
1. Enter system view. system-view
2. Enable symmetric load sharing. ip load-sharing symmetric enable
4
By default, symmetric load sharing is disabled.
Verifying and maintaining load sharing
Perform display tasks in any view.
•
Display the load sharing mode in use. display ip load-sharing mode slot slot-number
•
Display the load sharing path selected for a flow. display ip load-sharing path ingress-port interface-type interface-number packet-format { ipv4oe dest-ip ip-address [ src-ip ip-address ] | ipv6oe dest-ipv6 ipv6-address [ src-ipv6 ipv6-address ] }
[ dest-port port-id | ip-pro protocol-id | src-port port-id | vpn-instance vpn-instance-name ] *
Setting the maximum lifetime for routes and labels in the RIB
About this task
Perform this task to prevent routes of a certain protocol from being aged out due to slow protocol convergence resulting from a large number of route entries or long GR period.
Restrictions and guidelines for setting the maximum lifetime for routes and labels in the RIB
The configuration takes effect at the next protocol or RIB process switchover.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Set the maximum lifetime for IPv4 routes and labels in the RIB.
protocol protocol [ instance instance-name ] lifetime seconds
By default, the maximum lifetime for routes and labels in the RIB is 480 seconds.
Procedure (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Set the maximum lifetime for IPv6 routes and labels in the RIB.
protocol protocol [ instance instance-name ] lifetime seconds
By default, the maximum lifetime for routes and labels in the RIB is 480 seconds.
5
Setting the maximum lifetime for routes in the FIB
About this task
When GR or NSR is disabled, FIB entries must be retained for some time after a protocol process switchover or RIB process switchover. When GR or NSR is enabled, FIB entries must be removed immediately after a protocol or RIB process switchover to avoid routing issues. Perform this task to meet such requirements.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Set the maximum lifetime for IPv4 routes in the FIB.
fib lifetime seconds
By default, the maximum lifetime for routes in the FIB is 600 seconds.
Procedure (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Set the maximum lifetime for IPv6 routes in the FIB.
fib lifetime seconds
By default, the maximum lifetime for routes in the FIB is 600 seconds.
Enabling the RIB to flush route attribute information to the FIB
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Enable the RIB to flush route attribute information to the FIB. flush route-attribute protocol
By default, the RIB does not flush route attribute information to the FIB.
6
Enabling the enhanced ECMP mode
About enhanced ECMP mode
When one or multiple ECMP routes fail, the default ECMP mode enables the device to reallocate all traffic to the remaining routes.
The enhanced ECMP mode enables the device to reallocate only the traffic of the failed routes to the remaining routes, which ensures forwarding continuity.
Restrictions and guidelines for enabling the enhanced ECMP mode
This configuration takes effect at reboot. Make sure the reboot does not impact your network.
Enabling the IPv4 and IPv6 enhanced ECMP mode
1. Enter system view. system-view
2. Enable the IPv4 and IPv6 enhanced ECMP mode. ecmp mode enhanced
By default, the IPv4 and IPv6 enhanced ECMP mode is disabled.
Configuring RIB NSR
About this task
When an active/standby switchover occurs, nonstop routing (NSR) backs up routing information from the active process to the standby process to avoid routing flapping and ensure forwarding continuity.
RIB NSR provides faster route convergence than protocol NSR during an active/standby switchover.
Prerequisites for RIB NSR
Use this feature with protocol GR or NSR to avoid route timeouts and traffic interruption.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Enable IPv4 RIB NSR. non-stop-routing
By default, RIB NSR is disabled.
Procedure (IPv6)
1. Enter system view.
7
system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Enable IPv6 RIB NSR. non-stop-routing
By default, RIB NSR is disabled.
Configuring inter-protocol FRR
About this task
Inter-protocol fast reroute (FRR) enables fast rerouting between routes of different protocols. A backup next hop is automatically selected to reduce the service interruption time caused by unreachable next hops. When the next hop of the primary link fails, the traffic is redirected to the backup next hop.
Among the routes to the same destination in the RIB, a router adds the route with the highest preference to the FIB table. For example, if a static route and an OSPF route in the RIB have the same destination, the router adds the OSPF route to the FIB table by default. The next hop of the static route is selected as the backup next hop for the OSPF route. When the next hop of the OSPF route is unreachable, the backup next hop is used.
Restrictions and guidelines for inter-protocol FRR
This feature uses the next hop of a route from a different protocol as the backup next hop, which might cause loops.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Enable IPv4 RIB inter-protocol FRR. inter-protocol fast-reroute [ vpn-instance vpn-instance-name ]
By default, inter-protocol FRR is disabled.
If you do not specify a VPN instance, inter-protocol FRR is enabled for the public network.
Procedure (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Enable IPv6 RIB inter-protocol FRR. inter-protocol fast-reroute [ vpn-instance vpn-instance-name ]
8
By default, inter-protocol FRR is disabled.
If you do not specify a VPN instance, inter-protocol FRR is enabled for the public network.
Enabling IPv6 route fast switchover
About this task
This feature applies to a device that provides the same physical output interface for large numbers of routes, including ECMP routes and primary/secondary routes. When a link failure occurs on the interface, the device must perform the following tasks before switching the traffic to another route:
1. Deletes all ND entries for the link.
2. Instructs the FIB to delete the associated FIB entries.
This procedure is time consuming and interrupts traffic for a long time. To resolve this issue, you can enable IPv6 route fast switchover. This feature allows the device to instruct the FIB to delete the invalid FIB entries for route switchover first.
Procedure
1. Enter system view. system-view
2. Enable IPv6 route fast switchover. ipv6 route fast-switchover enable
By default, IPv6 route fast switchover is disabled.
Configuring routing policy-based recursive lookup
About this task
Configure routing policy-based recursive lookup to control route recursion results. For example, when a route changes, the routing protocol has to perform a route recursion if the next hop is indirectly connected. The routing protocol might select an incorrect path, which can cause traffic loss.
To prevent this problem, you can use a routing policy to filter out incorrect routes. The routes that pass the filtering of the routing policy will be used for route recursion.
Restrictions and guidelines for routing policy-based recursive lookup
The apply clauses in the specified routing policy cannot take effect.
Make sure a minimum of one related route can match the routing policy for correct traffic forwarding.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Configure routing policy-based recursive lookup.
protocol protocol nexthop recursive-lookup route-policy route-policy-name
By default, routing policy-based recursive lookup is not configured.
9
Procedure (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Configure routing policy-based recursive lookup.
protocol protocol nexthop recursive-lookup route-policy route-policy-name
By default, routing policy-based recursive lookup is not configured.
Configuring next hop recursion loop suppression
About next hop recursion loop suppression
A recursion loop occurs when a route recurses to a related route that recurses back to the route. It causes a route recursion failure and further lookup for a related route. If recursion loop persists, continuous route flapping will cause high system resource consumption and CPU utilization.
This feature enables the system to use a counter to record the number of route recursion failures.
When the counter reaches 20, the system suppresses route recursion for a specified period of time to save system resources on the device.
Restrictions and guidelines for configuring next hop recursion loop suppression
The configuration of disabling next hop recursion loop suppression takes effect immediately.
The setting of clearing the recursion loop counter takes effect for the next recursion loop suppression.
Disabling suppression for next hop recursion loop (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Disable next hop recursion loop suppression. nexthop recursive-lookup restrain disable
By default, next hop recursion loop suppression is enabled.
10
Setting the interval for clearing the recursion loop counter
(IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Set the interval for clearing the recursion loop counter.
nexthop recursive-lookup restrain clear-interval interval
By default, the interval for clearing the recursion loop counter is 600 seconds.
Disabling suppression for next hop recursion loop (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Disable next hop recursion loop suppression. nexthop recursive-lookup restrain disable
By default, next hop recursion loop suppression is enabled.
Setting the interval for clearing the recursion loop counter
(IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Set the interval for clearing the recursion loop counter.
nexthop recursive-lookup restrain clear-interval interval
By default, the interval for clearing the recursion loop counter is 600 seconds.
11
Setting the maximum number of active routes supported by the device
About this task
The feature allows you to set the maximum number of active IPv4/IPv6 routes supported by the device. When the maximum number of active IPv4/IPv6 routes is exceeded, the device still accepts new active routes but generates a system log message. You can take relevant actions based on the message to save system resources.
Procedure (IPv4)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv4 address family and enter its view. address-family ipv4
4. Set the maximum number of active IPv4 routes supported by the device.
routing-table limit number simply-alert
By default, the maximum number of active IPv4 routes is not set for the device.
Configuration in RIB IPv4 address family view limits the number of active IPv4 routes for the public network and all VPN instances.
Procedure (IPv6)
1. Enter system view. system-view
2. Enter RIB view. rib
3. Create the RIB IPv6 address family and enter its view. address-family ipv6
4. Set the maximum number of active IPv6 routes supported by the device.
routing-table limit number simply-alert
By default, the maximum number of active IPv6 routes is not set for the device.
Configuration in RIB IPv6 address family view limits the number of active IPv6 routes for the public network and all VPN instances.
Verifying and maintaining basic IP routing (IPv4)
Displaying IPv4 routing table information
Perform display tasks in any view.
•
Display routing table information. display ip routing-table [ all-vpn-instance | vpn-instance vpn-instance-name ] [ verbose ] display ip routing-table [ all-routes ]
•
Display information about routes permitted by an IPv4 basic ACL.
12
display ip routing-table [ vpn-instance vpn-instance-name ] acl ipv4-acl-number [ verbose ]
•
Display information about routes to a specific destination address. display ip routing-table [ vpn-instance vpn-instance-name ] ip-address [ mask-length | mask ] [ longer-match ] [ verbose ]
•
Display information about routes to a range of destination addresses. display ip routing-table [ vpn-instance vpn-instance-name ] ip-address1 to ip-address2 [ verbose ]
•
Display information about routes permitted by an IP prefix list. display ip routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ]
•
Display information about routes installed by a protocol. display ip routing-table [ vpn-instance vpn-instance-name ] protocol protocol [ inactive | verbose ]
•
Display brief routing table information, including maximum number of ECMP routes, maximum number of active routes, and number of remaining active routes. display ip routing-table [ vpn-instance vpn-instance-name ] summary
Displaying ECMP route information
Perform display tasks in any view.
•
Display ECMP mode information. display ecmp mode
Displaying IPv4 RIB information
Perform display tasks in any view.
•
Display route attribute information in the RIB. display rib attribute [ attribute-id ]
•
Display RIB GR state information. display rib graceful-restart
•
Display next hop information in the RIB. display rib nib [ self-originated ] [ nib-id ] [ verbose ] display rib nib protocol protocol [ verbose ]
•
Display next hop information for direct routes. display route-direct nib [ nib-id ] [ verbose ]
Displaying and clearing IPv4 routing table statistics
To display IPv4 route or route prefix statistics, execute the following command in any view: display ip routing-table [ all-routes | all-vpn-instance | vpn-instance vpn-instance-name ] [ prefix ] statistics
To clear route statistics, execute the following commands in user view:
• reset ip routing-table statistics protocol vpn-instance-name ] { protocol | all }
[ vpn-instance
13
• reset ip routing-table [ all-routes | all-vpn-instance ] statistics protocol { protocol | all }
Verifying and maintaining basic IP routing (IPv6)
Displaying IPv6 routing table information
Perform display tasks in any view.
•
Display IPv6 routing table information. display ipv6 routing-table [ all-vpn-instance | vpn-instance vpn-instance-name ] [ verbose ] display ipv6 routing-table all-routes
•
Display information about routes to an IPv6 destination address. display ipv6 routing-table [ vpn-instance vpn-instance-name ] ipv6-address [ prefix-length ] [ longer-match ] [ verbose ]
•
Display information about routes permitted by an IPv6 basic ACL. display ipv6 routing-table [ vpn-instance vpn-instance-name ] acl ipv6-acl-number [ verbose ]
•
Display information about routes to a range of IPv6 destination addresses. display ipv6 routing-table [ vpn-instance vpn-instance-name ]
ipv6-address1 to ipv6-address2 [ verbose ]
•
Display information about routes permitted by an IPv6 prefix list. display ipv6 routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ]
•
Display information about routes installed by an IPv6 protocol. display ipv6 routing-table [ vpn-instance vpn-instance-name ] protocol protocol [ inactive | verbose ]
•
Display brief IPv6 routing table information, including maximum number of ECMP routes, maximum number of active routes, and number of remaining active routes. display ipv6 routing-table [ vpn-instance vpn-instance-name ] summary
Displaying IPv6 ECMP route information
To display ECMP mode information, execute the following command in any view: display ecmp mode
Displaying IPv6 RIB information
Perform display tasks in any view.
•
Display route attribute information in the IPv6 RIB. display ipv6 rib attribute [ attribute-id ]
•
Display IPv6 RIB GR state information. display ipv6 rib graceful-restart
•
Display next hop information in the IPv6 RIB. display ipv6 rib nib [ self-originated ] [ nib-id ] [ verbose ]
14
display ipv6 rib nib protocol protocol [ verbose ]
•
Display next hop information for IPv6 direct routes. display ipv6 route-direct nib [ nib-id ] [ verbose ]
Displaying and clearing IPv6 routing table statistics
To display IPv6 route or route prefix statistics, execute the following command in any view: display ipv6 routing-table [ all-routes | all-vpn-instance | vpn-instance vpn-instance-name ] [ prefix ] statistics
To clear IPv6 route statistics, execute the following commands in user view:
• reset ipv6 routing-table statistics protocol vpn-instance-name ] { protocol | all }
[ vpn-instance
• reset ipv6 routing-table [ all-routes | all-vpn-instance ] statistics protocol { protocol | all }
Basic IP routing configuration examples
Example: Configuring load sharing based on source and destination addresses
Network configuration
As shown in Figure 1 , Device A has two equal-cost routes to Device B. Configure load sharing based
on source and destination addresses on Device A to forward packets through Device B to the destination IP address 1.2.3.4/24.
Figure 1 Network diagram
Device A HGE1/0/1
10.1.1.1/24
HGE1/0/1
10.1.1.2/24
Device B
IP network
HGE1/0/2
20.1.1.1/24
HGE1/0/2
20.1.1.2/24
Prerequisites
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
# On Device A, configure IP addresses for HundredGigE 1/0/1 and HundredGigE 1/0/2.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ip address 10.1.1.1 24
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ip address 20.1.1.1 24
[DeviceA-HundredGigE1/0/2] quit
# On Device B, configure IP addresses for HundredGigE 1/0/1 and HundredGigE 1/0/2.
15
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ip address 10.1.1.2 24
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ip address 20.1.1.2 24
[DeviceB-HundredGigE1/0/2] quit
# On Device A, configure two static routes to the destination IP address 1.2.3.4.
[DeviceA] ip route-static 1.2.3.4 24 10.1.1.2
[DeviceA] ip route-static 1.2.3.4 24 20.1.1.2
[DeviceA] quit
# On Device A, display FIB entries matching the destination IP address 1.2.3.4.
<DeviceA> display fib 1.2.3.4
FIB entry count: 2
Flag:
U:Usable G:Gateway H:Host B:Blackhole D:Dynamic S:Static
R:Relay F:FRR
Destination/Mask Nexthop Flag OutInterface/Token Label
1.2.3.0/24 10.1.1.2 USGR HGE1/0/1 Null
1.2.3.0/24 20.1.1.2 USGR HGE1/0/2 Null
# On Device A, configure per-flow load sharing based on source and destination IP addresses.
<DeviceA> system-view
[DeviceA] ip load-sharing mode per-flow dest-ip src-ip global
[DeviceA] quit
Verifying the configuration
# Verify that Device A implements load sharing.
<DeviceA> display counters outbound interface GigabitEthernet
Interface Total (pkts) Broadcast (pkts) Multicast (pkts) Err (pkts)
HGE1/0/1 1045 0 0 0
HGE1/0/2 1044 0 0 0
16
Configuring static routing
About static routes
Static routes are manually configured. If a network's topology is simple, you only need to configure static routes for the network to work correctly.
Static routes cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually.
Configuring a static route
1. Enter system view. system-view
2. Configure a static route.
Public network: ip route-static dest-address { mask-length | mask } { interface-type interface-number [ next-hop-address ] | next-hop-address
[ recursive-lookup host-route ] | vpn-instance d-vpn-instance-name next-hop-address [ recursive-lookup host-route ] } [ permanent | track track-entry-number ] [ preference preference ] [ tag tag-value ]
[ description text ] ip route-static dest-address { mask-length | mask } sr-policy policy-name [ preference preference ] [ tag tag-value ] [ description text ]
By default, no static route is configured.
You can associate Track with a static route to monitor the reachability of the next hops. For more information about Track, see High Availability Configuration Guide .
VPN: ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } { interface-type interface-number
[ next-hop-address ] | next-hop-address [ recursive-lookup host-route ]
[ public ] | vpn-instance d-vpn-instance-name next-hop-address
[ recursive-lookup host-route ] } [ permanent | track track-entry-number ] [ preference preference ] [ tag tag-value ]
[ description text ] ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } sr-policy policy-name [ preference preference ]
[ tag tag-value ] [ description text ]
By default, no static route is configured.
You can associate Track with a static route to monitor the reachability of the next hops. For more information about Track, see High Availability Configuration Guide .
3. (Optional.) Enable periodic sending of ARP requests to the next hops of static routes. ip route-static arp-request interval interval
By default, the device does not send ARP requests to the next hops of static routes.
4. (Optional.) Configure the default preference for static routes. ip route-static default-preference default-preference
The default setting is 60.
17
Configuring a static route group
About this task
This task allows you to batch create static routes with different prefixes but the same output interface and next hop.
You can create a static route group, and specify the static group in the ip route-static command. All prefixes in the static route group will be assigned the next hop and output interface specified in the ip route-static command.
Procedure
1. Enter system view. system-view
2. Create a static route group and enter its view. ip route-static-group group-name
By default, no static route group is configured.
3. Add a static route prefix to the static route group. prefix dest-address { mask-length | mask }
By default, no static route prefix is added to the static route group.
4. Return to system view. quit
5. Configure a static route.
Public network: ip route-static group group-name { interface-type interface-number
[ next-hop-address ] | next-hop-address [ recursive-lookup host-route ]
[ track track-entry-number ] | vpn-instance d-vpn-instance-name next-hop-address [ recursive-lookup host-route ] [ track track-entry-number ] } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]
VPN: ip route-static vpn-instance s-vpn-instance-name group group-name
{ interface-type interface-number [ next-hop-address ] | next-hop-address [ recursive-lookup host-route ] [ public ] [ track track-entry-number ] | vpn-instance d-vpn-instance-name next-hop-address [ recursive-lookup host-route ] [ track track-entry-number ] } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]
By default, no static route is configured.
Deleting static routes
About this task
To delete a static route, use the undo ip route-static command. To delete all static routes including the default route, use the delete static-routes all command.
Procedure
1. Enter system view. system-view
18
2. Delete all static routes.
Public network: delete static-routes all
VPN: delete vpn-instance vpn-instance-name static-routes all
CAUTION:
This command might interrupt network communication and cause packet forwarding failure.
Before executing the command, make sure you fully understand the potential impact on the network.
Configuring BFD for static routes
IMPORTANT:
Enabling BFD for a flapping route could worsen the situation.
About BFD
BFD provides a general-purpose, standard, medium-, and protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of the bidirectional forwarding paths between two routers for protocols, such as routing protocols and MPLS.
For more information about BFD, see High Availability Configuration Guide .
Configuring BFD control packet mode
About this task
This mode uses BFD control packets to detect the status of a link bidirectionally at a millisecond level.
BFD control packet mode can be applied to static routes with a direct next hop or with an indirect next hop.
Restrictions and guidelines for BFD control packet mode
If you use BFD control packet mode at the local end, you must use this mode also at the peer end.
Do not use BFD for a static route if the output interface of the static route is a tunnel interface.
Configuring BFD control packet mode for a static route (direct next hop)
1. Enter system view. system-view
2. Configure BFD control packet mode for a static route.
Public network:
ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference ] [ tag tag-value ] [ description text ]
VPN:
ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } interface-type interface-number
19
next-hop-address bfd control-packet [ preference preference ] [ tag tag-value ] [ description text ]
By default, BFD control packet mode for a static route is not configured.
Configuring BFD control packet mode for a static route (indirect next hop)
1. Enter system view. system-view
2. Configure BFD control packet mode for a static route.
Public network: ip route-static dest-address { mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference ] [ tag tag-value ] [ description text ]
VPN:
ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference ] [ tag tag-value ] [ description text ]
By default, BFD control packet mode for a static route is not configured.
Configuring BFD echo packet mode
About this task
With BFD echo packet mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability.
Restrictions and guidelines
You do not need to configure BFD echo packet mode at the peer end.
Do not use BFD for a static route with the output interface in spoofing state.
Do not use BFD for a static route if the output interface of the static route is a tunnel interface.
Procedure
1. Enter system view. system-view
2. Configure the source address of echo packets. bfd echo-source-ip ip-address
By default, the source address of echo packets is not configured.
For more information about this command, see High Availability Command Reference .
3. Configure BFD echo packet mode for a static route.
Public network: ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference ] [ tag tag-value ] [ description text ]
VPN: ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } interface-type interface-number
20
next-hop-address bfd echo-packet [ preference preference ] [ tag tag-value ] [ description text ]
By default, BFD echo packet mode for a static route is not configured.
Configuring static route FRR
About static route FRR
A link or router failure on a path can cause packet loss. Static route fast reroute (FRR) enables fast rerouting to minimize the impact of link or node failures.
Figure 2 Network diagram
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
interruption. You can either specify a backup next hop for FRR or enable FRR to automatically select a backup next hop (which must be configured in advance).
Restrictions and guidelines for static route FRR
•
Do not use static route FRR and BFD (for a static route) at the same time.
•
Equal-cost routes do not support static route FRR.
•
Besides the configured static route for FRR, the device must have another route to reach the destination.
When the state of the primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down, static route FRR quickly redirects traffic to the backup next hop. When the Layer 3 interfaces of the primary link are down, static route FRR temporarily redirects traffic to the backup next hop. In addition, the device searches for another route to reach the destination and redirects traffic to the new path if a route is found. If no route is found, traffic interruption occurs.
Configuring static route FRR by specifying a backup next hop
Restrictions and guidelines
A static route does not take effect when the backup output interface is unavailable.
To change the backup output interface or next hop, you must first remove the current setting. The backup output interface and next hop must be different from the primary output interface and next hop.
Procedure
1. Enter system view. system-view
2. Configure static route FRR.
Public network:
21
ip route-static dest-address { mask-length | mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type interface-number [ backup-nexthop backup-nexthop-address ] ] ]
[ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]
VPN: ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } interface-type interface-number
[ next-hop-address [ backup-interface interface-type interface-number
[ backup-nexthop backup-nexthop-address ] ] ] [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]
By default, static route FRR is disabled.
Configuring static route FRR to automatically select a backup next hop
1. Enter system view. system-view
2. Configure static route FRR to automatically select a backup next hop. ip route-static fast-reroute auto
By default, static route FRR is disabled from automatically selecting a backup next hop.
Enabling BFD echo packet mode for static route FRR
About this task
By default, static route FRR uses ARP to detect primary link failures. Perform this task to enable static route FRR to use BFD echo packet mode for fast failure detection on the primary link.
Procedure
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information about this command, see High Availability Command Reference .
3. Enable BFD echo packet mode for static route FRR. ip route-static primary-path-detect bfd echo
By default, BFD echo packet mode for static route FRR is disabled.
Verifying and maintaining static routing
Perform display tasks in any view.
•
Display static route information. display ip routing-table protocol static [ inactive | verbose ]
22
For more information about this command, see basic IP routing commands in Layer 3—IP
Routing Command Reference .
•
Display static route next hop information. display route-static nib [ nib-id ] [ verbose ]
•
Display static routing table information. display route-static routing-table [ ip-address { mask-length | mask } ] display route-static routing-table [ vpn-instance vpn-instance-name ]
[ ip-address { mask-length | mask } ]
Static route configuration examples
Example: Configuring basic static routes
Network configuration
As shown in Figure 3 , configure static routes on the devices for interconnections between any two
hosts.
Figure 3 Network diagram
Host B
1.1.6.2/24
HGE1/0/3
1.1.6.1/24
HGE1/0/2
1.1.4.1/30
HGE1/0/1
1.1.4.2/30
Device B
HGE1/0/2
1.1.5.5/30
HGE1/0/2
1.1.5.6/30
HGE1/0/1
1.1.2.3/24
Device A Device C
HGE1/0/1
1.1.3.1/24
Host C
1.1.3.2/24
Host A
1.1.2.2/24
Prerequisites
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routes:
# Configure a default route on Device A.
<DeviceA> system-view
[DeviceA] ip route-static 0.0.0.0 0.0.0.0 1.1.4.2
# Configure two static routes on Device B.
<DeviceB> system-view
[DeviceB] ip route-static 1.1.2.0 255.255.255.0 1.1.4.1
23
[DeviceB] ip route-static 1.1.3.0 255.255.255.0 1.1.5.6
# Configure a default route on Device C.
<DeviceC> system-view
[DeviceC] ip route-static 0.0.0.0 0.0.0.0 1.1.5.5
3. Configure the default gateways of Host A, Host B, and Host C as 1.1.2.3, 1.1.6.1, and 1.1.3.1.
(Details not shown.)
Verifying the configuration
# Display the static route information on Device A.
[DeviceA] display ip routing-table protocol static
Summary count : 1
Static Routing table status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/0 Static 60 0 1.1.4.2 HGE1/0/2
Static Routing table status : <Inactive>
Summary count : 0
# Display the static route information on Device B.
[DeviceB] display ip routing-table protocol static
Summary count : 2
Static Routing table status : <Active>
Summary count : 2
Destination/Mask Proto Pre Cost NextHop Interface
1.1.2.0/24 Static 60 0 1.1.4.1 HGE1/0/1
1.1.3.0/24 Static 60 0 1.1.5.6 HGE1/0/2
Static Routing table status : <Inactive>
Summary count : 0
# Use the ping command on Host B to test the reachability of Host A (Windows XP runs on the two hosts).
C:\Documents and Settings\Administrator>ping 1.1.2.2
Pinging 1.1.2.2 with 32 bytes of data:
Reply from 1.1.2.2: bytes=32 time=1ms TTL=126
Reply from 1.1.2.2: bytes=32 time=1ms TTL=126
Reply from 1.1.2.2: bytes=32 time=1ms TTL=126
Reply from 1.1.2.2: bytes=32 time=1ms TTL=126
Ping statistics for 1.1.2.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
24
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 1ms, Average = 1ms
# Use the tracert command on Host B to test the reachability of Host A.
C:\Documents and Settings\Administrator>tracert 1.1.2.2
Tracing route to 1.1.2.2 over a maximum of 30 hops
1 <1 ms <1 ms <1 ms 1.1.6.1
2 <1 ms <1 ms <1 ms 1.1.4.1
3 1 ms <1 ms <1 ms 1.1.2.2
Trace complete.
Example: Configuring BFD for static routes (direct next hop)
Network configuration
Configure the following, as shown in Figure 4 :
•
Configure a static route to subnet 120.1.1.0/24 on Device A.
•
Configure a static route to subnet 121.1.1.0/24 on Device B.
•
Enable BFD for both routes.
•
Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on
Device C.
When the link between Device A and Device B through the Layer 2 switch fails, BFD can detect the failure immediately. Device A then communicates with Device B through Device C.
Figure 4 Network diagram
121.1.1.0/24 120.1.1.0/24
Device A L2 Switch
HGE1/0/1
HGE1/0/2
BFD
HGE1/0/1
HGE1/0/1
HGE1/0/2
Device B
HGE1/0/2
Device C
Table 4 Interface and IP address assignment
Device
Device A
Device A
Device B
Device B
Device C
Device C
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
12.1.1.1/24
10.1.1.102/24
12.1.1.2/24
13.1.1.1/24
10.1.1.100/24
13.1.1.2/24
25
Prerequisites
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routes and BFD:
# Configure static routes on Device A and enable BFD control packet mode for the static route that traverses the Layer 2 switch.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 9
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] ip route-static 120.1.1.0 24 hundredgige 1/0/1 12.1.1.2 bfd control-packet
[DeviceA] ip route-static 120.1.1.0 24 hundredgige 1/0/2 10.1.1.100 preference 65
[DeviceA] quit
# Configure static routes on Device B and enable BFD control packet mode for the static route that traverses the Layer 2 switch.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 9
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] ip route-static 121.1.1.0 24 hundredgige 1/0/1 12.1.1.1 bfd control-packet
[DeviceB] ip route-static 121.1.1.0 24 hundredgige 1/0/2 13.1.1.2 preference 65
[DeviceB] quit
# Configure static routes on Device C.
<DeviceC> system-view
[DeviceC] ip route-static 120.1.1.0 24 13.1.1.1
[DeviceC] ip route-static 121.1.1.0 24 10.1.1.102
Verifying the configuration
# Display BFD sessions on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
4/7 12.1.1.1 12.1.1.2 Up 2000ms HGE1/0/1
The output shows that the BFD session has been created.
# Display static routes on Device A.
26
<DeviceA> display ip routing-table protocol static
Summary count : 1
Static Routing table status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 Static 60 0 12.1.1.2 HGE1/0/1
Static Routing table status : <Inactive>
Summary count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display static routes on Device A.
<DeviceA> display ip routing-table protocol static
Summary count : 1
Static Routing table status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 Static 65 0 10.1.1.100 HGE1/0/2
Static Routing table status : <Inactive>
Summary count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
Example: Configuring BFD for static routes (indirect next hop)
Network configuration
Figure 5 shows the network topology as follows:
•
Device A has a route to interface Loopback 1 (2.2.2.9/32) on Device B, with the output interface
HundredGigE 1/0/1.
•
Device B has a route to interface Loopback 1 (1.1.1.9/32) on Device A, with the output interface
HundredGigE 1/0/1.
•
Device D has a route to 1.1.1.9/32, with the output interface HundredGigE 1/0/1, and a route to
2.2.2.9/32, with the output interface HundredGigE 1/0/2.
Configure the following:
•
Configure a static route to subnet 120.1.1.0/24 on Device A.
•
Configure a static route to subnet 121.1.1.0/24 on Device B.
•
Enable BFD for both routes.
•
Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on both
Device C and Device D.
27
When the link between Device A and Device B through Device D fails, BFD can detect the failure immediately. Device A then communicates with Device B through Device C.
Figure 5 Network diagram
121.1.1.0/24 Loop1
1.1.1.9/32
Loop1
2.2.2.9/32
Device D
Device A
HGE1/0/1
HGE
HGE1/0/1
1/0
/2
BFD
HGE1/0/1
HGE1/0/2
1/
0/
2
Device B
HGE
HGE1/0/1 HGE1/0/2
120.1.1.0/24
Device C
Table 5 Interface and IP address assignment
Device
Device A
Device A
Device A
Device B
Device B
Device B
Device C
Device C
Device D
Device D
Prerequisites
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 1
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 1
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
12.1.1.1/24
10.1.1.102/24
1.1.1.9/32
11.1.1.2/24
13.1.1.1/24
2.2.2.9/32
10.1.1.100/24
13.1.1.2/24
12.1.1.2/24
11.1.1.2/24
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routes and BFD:
# Configure static routes on Device A and enable BFD control packet mode for the static route that traverses Device D.
<DeviceA> system-view
[DeviceA] bfd multi-hop min-transmit-interval 500
[DeviceA] bfd multi-hop min-receive-interval 500
[DeviceA] bfd multi-hop detect-multiplier 9
[DeviceA] ip route-static 120.1.1.0 24 2.2.2.9 bfd control-packet bfd-source 1.1.1.9
[DeviceA] ip route-static 120.1.1.0 24 hundredgige 1/0/2 10.1.1.100 preference 65
[DeviceA] quit
28
# Configure static routes on Device B and enable BFD control packet mode for the static route that traverses Device D.
<DeviceB> system-view
[DeviceB] bfd multi-hop min-transmit-interval 500
[DeviceB] bfd multi-hop min-receive-interval 500
[DeviceB] bfd multi-hop detect-multiplier 9
[DeviceB] ip route-static 121.1.1.0 24 1.1.1.9 bfd control-packet bfd-source 2.2.2.9
[DeviceB] ip route-static 121.1.1.0 24 hundredgige 1/0/2 13.1.1.2 preference 65
[DeviceB] quit
# Configure static routes on Device C.
<DeviceC> system-view
[DeviceC] ip route-static 120.1.1.0 24 13.1.1.1
[DeviceC] ip route-static 121.1.1.0 24 10.1.1.102
# Configure static routes on Device D.
<DeviceD> system-view
[DeviceD] ip route-static 120.1.1.0 24 11.1.1.2
[DeviceD] ip route-static 121.1.1.0 24 12.1.1.1
Verifying the configuration
# Display the BFD session information on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
4/7 1.1.1.9 2.2.2.9 Up 2000ms N/A
The output shows that the BFD session has been created.
# Display static routes on Device A.
<DeviceA> display ip routing-table protocol static
Summary count : 1
Static Routing table status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 Static 60 0 12.1.1.2 HGE1/0/1
Static Routing table status : <Inactive>
Summary count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display static routes on Device A.
<DeviceA> display ip routing-table protocol static
Summary count : 1
29
Static Routing table status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 Static 65 0 10.1.1.100 HGE1/0/2
Static Routing table status : <Inactive>
Summary count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
Example: Configuring static route FRR
Network configuration
As shown in Figure 6 , configure static routes on Device A, Device B, and Device C, and configure
static route FRR. When Link A becomes unidirectional, traffic can be switched to Link B immediately.
Figure 6 Network diagram
Device C
HGE
1/0
/1
HGE
1/0
/2
HGE
1/0
/1
Device
Link A
Loop0
HGE1/0/2
Device A
Table 6 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Device A
Device A
Device B
Device B
Device B
Device C
Device C
Prerequisites
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
12.12.12.1/24
13.13.13.1/24
1.1.1.1/32
24.24.24.4/24
13.13.13.2/24
4.4.4.4/32
12.12.12.2/24
24.24.24.2/24
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
30
2. Configure static route FRR on link A by using one of the following methods:
(Method 1.) Specify a backup next hop for static route FRR:
# Configure a static route on Device A, and specify HundredGigE 1/0/1 as the backup output interface and 12.12.12.2 as the backup next hop.
<DeviceA> system-view
[DeviceA] ip route-static 4.4.4.4 32 hundredgige 1/0/2 13.13.13.2 backup-interface hundredgige 1/0/1 backup-nexthop 12.12.12.2
# Configure a static route on Device B, and specify HundredGigE 1/0/1 as the backup output interface and 24.24.24.2 as the backup next hop.
<DeviceB> system-view
[DeviceB] ip route-static 1.1.1.1 32 hundredgige 1/0/2 13.13.13.1 backup-interface hundredgige 1/0/1 backup-nexthop 24.24.24.2
(Method 2.) Configure static route FRR to automatically select a backup next hop:
# Configure static routes on Device A, and enable static route FRR.
<DeviceA> system-view
[DeviceA] ip route-static 4.4.4.4 32 hundredgige 1/0/2 13.13.13.2
[DeviceA] ip route-static 4.4.4.4 32 hundredgige 1/0/1 12.12.12.2 preference 70
[DeviceA] ip route-static fast-reroute auto
# Configure static routes on Device B, and enable static route FRR.
<DeviceB> system-view
[DeviceB] ip route-static 1.1.1.1 32 hundredgige 1/0/2 13.13.13.1
[DeviceB] ip route-static 1.1.1.1 32 hundredgige 1/0/1 24.24.24.2 preference 70
[DeviceB] ip route-static fast-reroute auto
3. Configure static routes on Device C.
<DeviceC> system-view
[DeviceC] ip route-static 4.4.4.4 32 hundredgige 1/0/2 24.24.24.4
[DeviceC] ip route-static 1.1.1.1 32 hundredgige 1/0/1 12.12.12.1
Verifying the configuration
# Display route 4.4.4.4/32 on Device A to view the backup next hop information.
[DeviceA] display ip routing-table 4.4.4.4 verbose
Summary count : 1
Destination: 4.4.4.4/32
Protocol: Static
Process ID: 0
SubProtID: 0x0 Age: 04h20m37s
Cost: 0 Preference: 60
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.2
Label: NULL RealNextHop: 13.13.13.2
BkLabel: NULL BkNextHop: 12.12.12.2
SRLabel: NULL BkSRLabel: NULL
31
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display route 1.1.1.1/32 on Device B to view the backup next hop information.
[DeviceB] display ip routing-table 1.1.1.1 verbose
Summary count : 1
Destination: 1.1.1.1/32
Protocol: Static
Process ID: 0
SubProtID: 0x0 Age: 04h20m37s
Cost: 0 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.1
Label: NULL RealNextHop: 13.13.13.1
BkLabel: NULL BkNextHop: 24.24.24.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
32
Configuring a default route
A default route is used to forward packets that do not match any specific routing entry in the routing table. Without a default route, packets that do not match any routing entries are discarded and an
ICMP destination-unreachable packet is sent to the source.
A default route can be configured in either of the following ways:
•
The network administrator can configure a default route with both destination and mask being
0.0.0.0. For more information, see " Configuring static routing ."
•
Some dynamic routing protocols can generate a default route. For example, an upstream router running OSPF can generate a default route and advertise it to other routers. These routers install the default route with the next hop being the upstream router. For more information, see the respective chapters on these routing protocols in this configuration guide.
33
Configuring RIP
About RIP
Routing Information Protocol (RIP) is a distance-vector IGP suited to small-sized networks. It employs UDP to exchange route information through port 520.
RIP routing metrics
RIP uses a hop count to measure the distance to a destination. The hop count from a router to a directly connected network is 0. The hop count from a router to a directly connected router is 1. To limit convergence time, RIP restricts the value range of the metric from 0 to 15. A destination with a metric value of 16 (or greater) is considered unreachable. For this reason, RIP is not suitable for large-sized networks.
RIP route entries
RIP stores routing entries in a database. Each routing entry contains the following elements:
•
Destination address —IP address of a destination host or a network.
•
Next hop —IP address of the next hop.
•
Egress interface —Egress interface of the route.
•
Metric —Cost from the local router to the destination.
•
Route time —Time elapsed since the last update. The time is reset to 0 when the routing entry is updated.
•
Route tag
—Used for route control. For more information, see " Configuring routing policies ."
RIP operation
RIP works as follows:
1. RIP sends request messages to neighboring routers. Neighboring routers return response messages that contain their routing tables.
2. RIP uses the received responses to update the local routing table and sends triggered update messages to its neighbors. All RIP routers on the network do this to learn latest routing information.
3. RIP periodically sends the local routing table to its neighbors. After a RIP neighbor receives the message, it updates its routing table, selects optimal routes, and sends an update to other neighbors. RIP ages routes to keep only valid routes.
Routing loop prevention
RIP uses the following mechanisms to prevent routing loops:
•
Counting to infinity —A destination with a metric value of 16 is considered unreachable. When a routing loop occurs, the metric value of a route will increment to 16 to avoid endless looping.
•
Triggered updates —RIP immediately advertises triggered updates for topology changes to reduce the possibility of routing loops and to speed up convergence.
•
Split horizon —Disables RIP from sending routes through the interface where the routes were learned to prevent routing loops and save bandwidth.
34
•
Poison reverse —Enables RIP to set the metric of routes received from a neighbor to 16 and sends these routes back to the neighbor. The neighbor can delete such information from its routing table to prevent routing loops.
RIP versions
There are two RIP versions, RIPv1 and RIPv2.
RIPv1 is a classful routing protocol. It advertises messages only through broadcast. RIPv1 messages do not carry mask information, so RIPv1 can only recognize natural networks such as
Class A, B, and C. For this reason, RIPv1 does not support discontiguous subnets.
RIPv2 is a classless routing protocol. It has the following advantages over RIPv1:
•
Supports route tags to implement flexible route control through routing policies.
•
Supports masks, route summarization, and CIDR.
•
Supports designated next hops to select the best ones on broadcast networks.
•
Supports multicasting route updates so only RIPv2 routers can receive these updates to reduce resource consumption.
•
Supports plain text authentication and MD5 authentication to enhance security.
RIPv2 supports two transmission modes: broadcast and multicast. Multicast is the default mode using 224.0.0.9 as the multicast address. An interface operating in RIPv2 broadcast mode can also receive RIPv1 messages.
Protocols and standards
•
RFC 1058, Routing Information Protocol
•
RFC 1723, RIP Version 2 - Carrying Additional Information
•
RFC 1721, RIP Version 2 Protocol Analysis
•
RFC 1722, RIP Version 2 Protocol Applicability Statement
•
RFC 1724, RIP Version 2 MIB Extension
•
RFC 2082, RIPv2 MD5 Authentication
•
RFC 2091, Triggered Extensions to RIP to Support Demand Circuits
•
RFC 2453, RIP Version 2
RIP tasks at a glance
To configure RIP, perform the following tasks:
1.
a.
b.
(Optional.) Controlling RIP reception and advertisement on interfaces
c.
(Optional.) Configuring a RIP version
d.
To enable RIP on a link that does not support broadcast or multicast, you must manually specify a RIP neighbor.
2.
(Optional.) Configuring RIP route control
Configuring an additional routing metric
Configuring RIPv2 route summarization
Disabling host route reception
35
Configuring received/redistributed route filtering
Configuring RIP route redistribution
3.
(Optional.) Tuning and optimizing RIP networks
Enabling split horizon and poison reverse
Setting the maximum number of RIP ECMP routes
Setting the RIP triggered update interval
Configuring the RIP packet sending rate
Setting the maximum length of RIP packets
Setting the DSCP value for outgoing RIP packets
4.
(Optional.) Configuring RIP network management
5. Enhancing RIP availability
6.
(Optional.) Enhancing RIP security
Enabling zero field check for incoming RIPv1 messages
Enabling source IP address check for incoming RIP updates
Configuring RIPv2 message authentication
Configuring basic RIP
Restrictions and guidelines for configuring basic RIP
To enable multiple RIP processes on a router, you must specify an ID for each process. A RIP process ID has only local significance. Two RIP routers having different process IDs can also exchange RIP packets.
Enabling RIP
About this task
You can enable RIP on a network and specify a wildcard mask for the network. After that, only the interface attached to the network runs RIP.
Restrictions and guidelines
If you configure RIP settings in interface view before enabling RIP, the settings do not take effect until
RIP is enabled.
If a physical interface is attached to multiple networks, you cannot advertise these networks in different RIP processes.
You cannot enable multiple RIP processes on a physical interface.
The rip enable command takes precedence over the network command.
36
Enabling RIP on a network
1. Enter system view. system-view
2. Enable RIP and enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
By default, RIP is disabled.
3. Enable RIP on a network.
network network-address [ wildcard-mask ]
By default, RIP is disabled on a network.
The network 0.0.0.0 command can enable RIP on all interfaces in a single process, but does not apply to multiple RIP processes.
Enabling RIP on an interface
1. Enter system view. system-view
2. Enable RIP and enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
By default, RIP is disabled.
3. Return to system view. quit
4. Enter interface view. interface interface-type interface-number
5. Enable RIP on the interface. rip process-id enable [ exclude-subip ]
By default, RIP is disabled on an interface.
Controlling RIP reception and advertisement on interfaces
About this task
You can perform this task to configure the following features:
•
Suppressing an interface. The suppressed interface can receive RIP messages but cannot send RIP messages.
•
Disabling an interface from sending RIP messages.
•
Disabling an interface from receiving RIP messages.
Restrictions and guidelines for RIP reception and advertisement control on interfaces
An interface suppressed by using the silent-interface command can only receive RIP messages. It cannot send RIP messages. You can use the silent-interface all command to suppress all interfaces. The silent-interface command takes precedence over the rip input and rip output commands.
Suppressing an interface
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
37
3. Suppress an interface. silent-interface { interface-type interface-number | all }
By default, all RIP-enabled interfaces can send RIP messages.
The suppressed interface can still receive RIP messages and respond to unicast requests containing unknown ports.
Disabling an interface from receiving RIP messages
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Disable an interface from receiving RIP messages. undo rip input
By default, a RIP-enabled interface can receive RIP messages.
Disabling an interface from sending RIP messages
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Disable an interface from sending RIP messages. undo rip output
By default, a RIP-enabled interface can send RIP messages.
Configuring a RIP version
About this task
You can configure a global RIP version in RIP view or an interface-specific RIP version in interface view.
An interface preferentially uses the interface-specific RIP version. If no interface-specific version is specified, the interface uses the global RIP version. If neither a global nor interface-specific RIP version is configured, the interface sends RIPv1 broadcasts and can receive the following:
•
RIPv1 broadcasts and unicasts.
•
RIPv2 broadcasts, multicasts, and unicasts.
Procedure
1. Enter system view. system-view
2. Specify a RIP version.
Execute the following commands in sequence to specify a global RIP version: rip [ process-id ] [ vpn-instance vpn-instance-name ] version { 1 | 2 }
By default, no global version is specified. An interface sends RIPv1 broadcasts, and can receive RIPv1 broadcasts and unicasts, and RIPv2 broadcasts, multicasts, and unicasts.
Execute the following commands in sequence to specify a RIP version on an interface: interface interface-type interface-number rip version { 1 | 2 [ broadcast | multicast ] }
38
By default, no interface-specific RIP version is specified. The interface sends RIPv1 broadcasts, and can receive RIPv1 broadcasts and unicasts, and RIPv2 broadcasts, multicasts, and unicasts.
Specifying a RIP neighbor
About this task
Typically RIP messages are sent in broadcast or multicast. To enable RIP on a link that does not support broadcast or multicast, you must manually specify a RIP neighbor.
Restrictions and guidelines
As a best practice, do not use the peer ip-address command to specify a directly connected neighbor.
The neighbor might receive a route update in both unicast and multicast (or broadcast) messages from the device.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify a RIP neighbor. peer ip-address
By default, RIP does not unicast updates to any peer.
4. Disable source IP address check on inbound RIP updates. undo validate-source-address
By default, source IP address check is enabled on inbound RIP updates.
If the specified neighbor is not directly connected, disable source address check on incoming updates.
Configuring RIP route control
Configuring an additional routing metric
About this task
An additional routing metric (hop count) can be added to the metric of an inbound or outbound RIP route.
•
An outbound additional metric is added to the metric of a sent route, and it does not change the route's metric in the routing table.
•
An inbound additional metric is added to the metric of a received route before the route is added into the routing table, and the route's metric is changed. If the sum of the additional metric and the original metric is greater than 16, the metric of the route is 16.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify an inbound additional routing metric.
39
rip metricin [ route-policy route-policy-name ] value
By default, the additional metric of an inbound route is 0.
4. Specify an outbound additional routing metric. rip metricout [ route-policy route-policy-name ] value
By default, the additional metric of an outbound route is 1.
Configuring RIPv2 route summarization
About this task
Perform this task to summarize contiguous subnets into a summary network and sends the network to neighbors. The smallest metric among all summarized routes is used as the metric of the summary route.
You can use the following methods to summarize routes in RIPv2:
•
Automatic summarization —Configure RIPv2 to generate a natural network for contiguous subnets. For example, suppose there are three subnet routes 10.1.1.0/24, 10.1.2.0/24, and
10.1.3.0/24. Automatic summarization automatically creates and advertises a summary route
10.0.0.0/8 instead of the more specific routes.
•
Manual summarization —Manually configure a summary route. RIPv2 advertises the summary route rather than more specific routes. For example, suppose contiguous subnets routes 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24 exist in the routing table. You can create a summary route 10.1.0.0/16 on HundredGigE 1/0/1 to advertise the summary route instead of the more specific routes. By default, natural masks are used to advertise summary routes. To manually configure a summary route on an interface, you must first disable RIPv2 automatic route summarization.
Restrictions and guidelines
To prevent loops caused by route summarization, create a black hole route by specifying interface
NULL 0 as the output interface of the summary route. Packets that match the black hole route are dropped.
Enabling RIPv2 automatic route summarization
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable RIPv2 automatic route summarization. summary
By default, RIPv2 automatic route summarization is enabled.
If subnets in the routing table are not contiguous, disable automatic route summarization to advertise more specific routes.
Advertising a summary route
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Disable RIPv2 automatic route summarization. undo summary
By default, RIPv2 automatic route summarization is enabled.
40
4. Return to system view. quit
5. Enter interface view.
interface interface-type interface-number
6. Configure a summary route.
rip summary-address ip-address { mask-length | mask }
By default, no summary route is configured.
Disabling host route reception
About this task
This task disables RIPv2 from receiving host routes from the same network to save network resources. This feature does not apply to RIPv1.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Disable RIP from receiving host routes. undo host-route
By default, RIP receives host routes.
Advertising a default route
About this task
You can advertise a default route on all RIP interfaces in RIP view or on a specific RIP interface in interface view. The interface view setting takes precedence over the RIP view settings.
To disable an interface from advertising a default route, use the rip default-route no-originate command on the interface.
The router enabled to advertise a default route does not accept default routes from RIP neighbors.
Procedure
1. Enter system view. system-view
2. Advertise a default route.
Execute the following commands in sequence to configure RIP to advertise a default route: rip [ process-id ] [ vpn-instance vpn-instance-name ] default-route { only | originate } [ cost cost-value | route-policy route-policy-name ] *
By default, RIP does not advertise a default route.
Execute the following commands in sequence to configure a RIP interface to advertise a default route: interface interface-type interface-number rip default-route { { only | originate } [ cost cost-value |
route-policy route-policy-name ] * | no-originate }
41
By default, a RIP interface can advertise a default route if the RIP process is enabled to advertise a default route.
Configuring received/redistributed route filtering
About this task
This task allows you to create a policy to filter received or redistributed routes that match specific criteria such as an ACL or IP prefix list.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure the filtering of received routes. filter-policy { ipv4 acl-number | gateway prefix-list-name | prefix-list prefix-list-name [ gateway prefix-list-name ] } import
[ interface-type interface-number ]
By default, the filtering of received routes is not configured.
This command filters received routes. Filtered routes are not installed into the routing table or advertised to neighbors.
4. Configure the filtering of redistributed routes. filter-policy { ipv4 acl-number | prefix-list prefix-list-name } export [ interface-type interface-number | bgp | direct | [ isis | ospf | rip ] [ process-id ] | static ]
By default, the filtering of redistributed routes is not configured.
This command filters redistributed routes, including routes redistributed with the import-route command.
Setting a preference for RIP
About this task
If multiple IGPs find routes to the same destination, the route found by the IGP that has the highest priority is selected as the optimal route. Perform this task to assign a preference to RIP. The smaller the preference value, the higher the priority.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set a preference for RIP. preference { preference | route-policy route-policy-name } *
The default preference for RIP is 100.
42
Configuring RIP route redistribution
About this task
Perform this task to configure RIP to redistribute routes from other routing protocols, including OSPF,
IS-IS, BGP, static, and direct.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure route redistribution.
Redistribute BGP routes. import-route bgp [ as-number ] [ allow-ibgp ] [ cost cost-value |
route-policy route-policy-name | tag tag ] *
Redistribute direct or static routes. import-route { direct | static } [ cost cost-value | route-policy
route-policy-name | tag tag ] *
Redistribute IS-IS routes, OSPF routes, or routes from other RIP processes.
import-route { isis | ospf | rip } [ process-id | all-processes ]
[ allow-direct | cost cost-value | route-policy route-policy-name |
tag tag ] *
By default, RIP does not redistribute routes.
This command can redistribute only active routes. To view active routes, use the display ip routing-table protocol command.
4. (Optional.) Set a default cost for redistributed routes.
default cost cost-value
The default cost for redistributed routes is 0.
Tuning and optimizing RIP networks
Setting RIP timers
About this task
You can change the RIP network convergence speed by adjusting the following RIP timers:
•
Update timer —Specifies the interval between route updates.
•
Timeout timer —Specifies the route aging time. If no update for a route is received within the aging time, the metric of the route is set to 16.
•
Suppress timer —Specifies how long a RIP route stays in suppressed state. When the metric of a route is 16, the route enters the suppressed state. A suppressed route can be replaced by an updated route that is received from the same neighbor before the suppress timer expires and has a metric less than 16.
•
Garbage-collect timer —Specifies the interval from when the metric of a route becomes 16 to when it is deleted from the routing table. RIP advertises the route with a metric of 16. If no update is announced for that route before the garbage-collect timer expires, the route is deleted from the routing table.
43
Restrictions and guidelines
To avoid unnecessary traffic or route flapping, configure identical RIP timer settings on RIP routers.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set RIP timers. timers { garbage-collect garbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value } *
The default settings are as follows:
The garbage-collect timer is 120 seconds.
The suppress timer is 120 seconds.
The timeout timer is 180 seconds.
The update timer is 30 seconds.
Enabling split horizon and poison reverse
About this task
The split horizon and poison reverse features can prevent routing loops.
•
Split horizon disables RIP from sending routes through the interface where the routes were learned to prevent routing loops between adjacent routers.
•
Poison reverse allows RIP to send routes through the interface where the routes were learned.
The metric of these routes is always set to 16 (unreachable) to avoid routing loops between neighbors.
Restrictions and guidelines
If both split horizon and poison reverse are configured, only the poison reverse feature takes effect.
Enabling split horizon
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable split horizon. rip split-horizon
By default, split horizon is enabled.
Enabling poison reverse
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable poison reverse. rip poison-reverse
By default, poison reverse is disabled.
44
Setting the maximum number of RIP ECMP routes
About this task
Perform this task to use ECMP routes to share the load of the RIP network.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the maximum number of RIP ECMP routes. maximum load-balancing number
By default, the maximum number of RIP ECMP routes equals the maximum number of ECMP routes, which is configurable by using the max-ecmp-num command.
Setting the RIP triggered update interval
About this task
Perform this task to avoid network overhead and reduce system resource consumption caused by frequent RIP triggered updates.
You can use the timer triggered command to set the maximum interval, minimum interval, and incremental interval for sending RIP triggered updates.
•
For a stable network, the minimum-interval is used.
•
If network changes become frequent, the incremental interval incremental-interval is used to extend the triggered update sending interval until the maximum-interval is reached.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the RIP triggered update interval.
timer triggered maximum-interval [ minimum-interval
[ incremental-interval ] ]
The default settings are as follows:
The maximum interval is 5 seconds.
The minimum interval is 50 milliseconds.
The incremental interval is 200 milliseconds.
Configuring the RIP packet sending rate
About this task
Perform this task to set the interval for sending RIP packets and the maximum number of RIP packets that can be sent at each interval. This feature can avoid excessive RIP packets from affecting system performance and consuming too much bandwidth.
45
Procedure
1. Enter system view. system-view
2. Configure the RIP packet sending rate.
Execute the following commands in sequence to configure the RIP packet sending rate for all interfaces: rip [ process-id ] [ vpn-instance vpn-instance-name ]
output-delay time count count
By default, an interface sends up to three RIP packets every 20 milliseconds.
Execute the following commands in sequence to configure the RIP packet sending rate for an interface: interface interface-type interface-number
rip output-delay time count count
By default, the interface uses the RIP packet sending rate configured for the RIP process that the interface runs.
Setting the maximum length of RIP packets
CAUTION:
The supported maximum length of RIP packets varies by vendor. Use this feature with caution to avoid compatibility issues.
About this task
The packet length of RIP packets determines how many routes can be carried in a RIP packet. Set the maximum length of RIP packets to make good use of link bandwidth.
When authentication is enabled, follow these guidelines to ensure packet forwarding:
•
For simple authentication, the maximum length of RIP packets must be no less than 52 bytes.
•
For MD5 authentication (with packet format defined in RFC 2453), the maximum length of RIP packets must be no less than 56 bytes.
•
For MD5 authentication (with packet format defined in RFC 2082), the maximum length of RIP packets must be no less than 72 bytes.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the maximum length of RIP packets. rip max-packet-length value
By default, the maximum length of RIP packets is 512 bytes.
Setting the DSCP value for outgoing RIP packets
About this task
The DSCP value specifies the precedence of outgoing packets.
46
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the DSCP value for outgoing RIP packets.
dscp dscp-value
By default, the DSCP value for outgoing RIP packets is 48.
Configuring RIP network management
About this task
You can use network management software to manage the RIP process to which MIB is bound.
Procedure
1. Enter system view. system-view
2. Bind MIB to a RIP process. rip mib-binding process-id
By default, MIB is bound to the RIP process with the smallest process ID.
Configuring RIP GR
About this task
GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.
Two routers are required to complete a GR process. The following are router roles in a GR process:
•
GR restarter —Graceful restarting router. It must have GR capability.
•
GR helper —A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
After RIP restarts on a router, the router must learn RIP routes again and update its FIB table, which causes network disconnections and route reconvergence.
With the GR feature, the restarting router (known as the GR restarter) can notify the event to its GR capable neighbors. GR capable neighbors (known as GR helpers) maintain their adjacencies with the router within a GR interval. During this process, the FIB table of the router does not change. After the restart, the router contacts its neighbors to retrieve its FIB.
By default, a RIP-enabled device acts as the GR helper. Perform this task on the GR restarter.
Restrictions and guidelines
You cannot enable RIP NSR on a device that acts as GR restarter.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
47
3. Enable GR for RIP. graceful-restart
By default, RIP GR is disabled.
4. (Optional.) Set the GR interval. graceful-restart interval interval
By default, the GR interval is 60 seconds.
Enabling RIP NSR
About this task
Nonstop Routing (NSR) allows the device to back up the routing information from the active RIP process to the standby RIP process. After an active/standby switchover, NSR can complete route regeneration without tearing down adjacencies or impacting forwarding services.
NSR does not require the cooperation of neighboring devices to recover routing information, and it is typically used more often than GR.
Restrictions and guidelines
A device that has RIP NSR enabled cannot act as GR restarter.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable RIP NSR. non-stop-routing
By default, RIP NSR is disabled.
RIP NSR enabled for a RIP process takes effect only on that process. As a best practice, enable RIP NSR for each process if multiple RIP processes exist.
Configuring BFD for RIP
About BFD for RIP
RIP detects route failures by periodically sending requests. If it receives no response for a route within a certain time, RIP considers the route unreachable. To speed up convergence, perform this task to enable BFD for RIP. For more information about BFD, see High Availability Configuration
Guide .
RIP supports the following BFD detection modes:
•
Single-hop echo detection —Detection mode for a directly connected neighbor. In this mode, a BFD session is established only when the directly connected neighbor has route information to send.
•
Single-hop echo detection for a specific destination —Detection mode for a directly connected neighbor. In this mode, a BFD session is established to the specified RIP neighbor when RIP is enabled on the local interface. When BFD detects a unidirectional link, the local device will not receive or send any RIP packets through the interface to improve convergence speed. When the link recovers, the interface can send RIP packets again.
48
•
Bidirectional control detection —Detection mode for both directly and indirectly connected neighbors. In this mode, a BFD session is established only when both ends have routes to send and BFD is enabled on the receiving interface.
Restrictions and guidelines
The bfd all-interfaces enable command enables BFD for RIP on all interfaces of a RIP process. If the link to one of the interfaces becomes unstable, the BFD session might flap on the interface. This will affect the stability of the network. To resolve this problem, use the rip bfd disable command to disable BFD on that interface.
Configuring single-hop echo detection (for a directly connected RIP neighbor)
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
3. Enable BFD for RIP.
Execute the following commands in sequence to enable BFD in RIP view: rip [ process-id ] [ vpn-instance vpn-instance-name ] bfd all-interfaces enable
Execute the following commands in sequence to enable BFD in interface view: interface interface-type interface-number rip bfd enable
By default, BFD for RIP is disabled.
Configuring single-hop echo detection (for a specific destination)
Restrictions and guidelines
This feature applies only to RIP neighbors that are directly connected.
Procedure
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, no source IP address is configured for BFD echo packets.
3. Enter interface view. interface interface-type interface-number
4. Enable BFD for RIP.
rip bfd enable destination ip-address
By default, BFD for RIP is disabled.
49
Configuring bidirectional control detection for an indirectly connected neighbor
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify a RIP neighbor.
peer ip-address
By default, RIP does not unicast updates to any peer.
Because the undo peer command does not remove the neighbor relationship immediately, executing the command cannot bring down the BFD session immediately.
4. Enable BFD for RIP.
Enable BFD on all interfaces of a RIP process.
bfd all-interfaces enable
Execute the following commands in sequence to enable BFD on an interface. interface interface-type interface-number rip bfd enable
By default, BFD for RIP is disabled.
Configuring bidirectional control detection for a directly connected neighbor
1. Enter system view. system-view
2. Enable BFD for RIP.
Execute the following commands in sequence to enable BFD in RIP view: rip [ process-id ] [ vpn-instance vpn-instance-name ] bfd all-interfaces enable ctrl
Execute the following commands in sequence to enable BFD in interface view: interface interface-type interface-number rip bfd enable ctrl
By default, BFD for RIP is disabled.
Configuring RIP FRR
About RIP FRR
A link or router failure on a path can cause packet loss and even routing loop until RIP completes routing convergence based on the new network topology. FRR enables fast rerouting to minimize the impact of link or node failures.
50
Figure 7 Network diagram for RIP FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
As shown in Figure 7 , configure FRR on Router B by using a routing policy to specify a backup next
hop. When the primary link fails, RIP directs packets to the backup next hop. At the same time, RIP calculates the shortest path based on the new network topology, and forwards packets over that path after network convergence.
Restrictions and guidelines for RIP FRR
RIP FRR takes effect only for RIP routes learned from directly connected neighbors.
RIP FRR is available only when the state of primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down.
Equal-cost routes do not support RIP FRR.
Enabling RIP FRR
1. Enter system view. system-view
2. Configure a routing policy for FRR.
You must specify a next hop by using the apply fast-reroute backup-interface command in the routing policy.
For more information about routing policy configuration, see " Configuring routing policies ."
3. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
4. Enable RIP FRR.
fast-reroute route-policy route-policy-name
By default, RIP FRR is disabled.
Enabling BFD bidirectional control detection for RIP FRR
About this task
By default, RIP FRR does not use BFD to detect primary link failures. For quicker RIP FRR, use BFD bidirectional control detection on the primary link of redundant links to detect link failure. BFD bidirectional control detection must be configured on both ends of the link to take effect.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD bidirectional control detection for RIP FRR.
51
rip primary-path-detect bfd ctrl
By default, BFD bidirectional control detection for RIP FRR is disabled.
Enabling BFD single-hop echo detection for RIP FRR
About this task
By default, RIP FRR does not use BFD to detect primary link failures. For quicker RIP FRR, use BFD single-hop echo detection on the primary link of redundant links to detect link failure.
Procedure
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interfaces.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD for RIP FRR. rip primary-path-detect bfd echo
By default, BFD for RIP FRR is disabled.
Enhancing RIP security
Enabling zero field check for incoming RIPv1 messages
About this task
Some fields in the RIPv1 message must be set to zero. These fields are called "zero fields." You can enable zero field check for incoming RIPv1 messages. If a zero field of a message contains a non-zero value, RIP does not process the message. If you are certain that all messages are trustworthy, disable zero field check to save CPU resources.
This feature does not apply to RIPv2 packets, because they have no zero fields.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable zero field check for incoming RIPv1 messages. checkzero
By default, zero field check is disabled for incoming RIPv1 messages.
52
Enabling source IP address check for incoming RIP updates
About this task
Perform this task to enable source IP address check for incoming RIP updates.
•
Upon receiving a message on an Ethernet interface, RIP compares the source IP address of the message with the IP address of the interface. If they are not in the same network segment,
RIP discards the message.
Procedure
1. Enter system view. system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable source IP address check for incoming RIP messages. validate-source-address
By default, source IP address check is disabled for incoming RIP updates.
Configuring RIPv2 message authentication
About this task
Perform this task to enable authentication on RIPv2 messages.
RIPv2 supports simple authentication, MD5 authentication, and keychain authentication.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure RIPv2 authentication. rip authentication-mode { keychain keychain-name { rfc2453 | rfc4822 }
| md5 { rfc2082 { cipher | plain } string key-id | rfc2453 { cipher | plain } string } | simple { cipher | plain } string }
By default, RIPv2 authentication is not configured.
RIPv1 does not support authentication. Although you can specify an authentication mode for
RIPv1 in interface view, the configuration does not take effect.
For information about the keychain feature, see Security Configuration Guide .
Verifying and maintaining RIP
Verifying RIP configuration and running status
Verifying basic RIP configuration and running status
Perform display tasks in any view.
•
Display RIP current status and configuration information. display rip [ process-id ]
•
Display active routes in the RIP database.
53
display rip process-id database [ ip-address { mask-length | mask } ]
•
Display RIP interface information.
display rip process-id interface [ interface-type interface-number ]
•
Display neighbor information for a RIP process.
display rip process-id neighbor [ interface-type interface-number ]
•
Display routing information for a RIP process.
display rip process-id route [ ip-address { mask-length | mask }
[ verbose ] | peer ip-address | statistics ]
Verifying RIP availability configuration
Perform display tasks in any view.
•
Display RIP GR information. display rip [ process-id ] graceful-restart
•
Display RIP NSR information. display rip [ process-id ] non-stop-routing
Clearing statistics for a RIP process
To clear the statistics for a RIP process, execute the following command in user view: reset rip process-id statistics
Resetting a RIP process
To reset a RIP process, execute the following command in user view:
reset rip process-id process
RIP configuration examples
Example: Configuring basic RIP
Network configuration
As shown in Figure 8 , enable RIPv2 on all interfaces on Device A and Device B. Configure Device B
to not advertise route 10.2.1.0/24 to Device A, and to accept only route 2.1.1.0/24 from Device A.
Figure 8 Network diagram
HGE1/0/3
3.1.1.1/24
HGE1/0/2
2.1.1.1/24
Device A
HGE1/0/1
1.1.1.1/24
Procedure
HGE1/0/1
1.1.1.2/24
Device B
HGE1/0/3
10.2.1.1/24
HGE1/0/2
10.1.1.2/24
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
54
1. Configure IP addresses for the interfaces. (Details not shown.)
2. Enable RIP.
# Enable RIP on the specified networks on Device A.
<DeviceA> system-view
[DeviceA] rip
[DeviceA-rip-1] network 1.0.0.0
[DeviceA-rip-1] network 2.0.0.0
[DeviceA-rip-1] network 3.0.0.0
[DeviceA-rip-1] quit
# Enable RIP on the specified interfaces on Device B.
<DeviceB> system-view
[DeviceB] rip
[DeviceB-rip-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] rip 1 enable
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] rip 1 enable
[DeviceB-HundredGigE1/0/2] quit
[DeviceB] interface hundredgige 1/0/3
[DeviceB-HundredGigE1/0/3] rip 1 enable
[DeviceB-HundredGigE1/0/3] quit
# Display the RIP routing table on Device A.
[DeviceA] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 1.1.1.2 1 0 RAOF 9
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
1.1.1.0/24 0.0.0.0 0 0 RDOF -
2.1.1.0/24 0.0.0.0 0 0 RDOF -
3.1.1.0/24 0.0.0.0 0 0 RDOF -
The output shows that RIPv1 uses natural masks to advertise routing information.
3. Configure a RIP version:
# Configure RIPv2 on Device A.
[DeviceA] rip
[DeviceA-rip-1] version 2
[DeviceA-rip-1] undo summary
[DeviceA-rip-1] quit
# Configure RIPv2 on Device B.
[DeviceB] rip
[DeviceB-rip-1] version 2
[DeviceB-rip-1] undo summary
[DeviceB-rip-1] quit
55
# Display the RIP routing table on Device A.
[DeviceA] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 1.1.1.2 1 0 RAOF 87
10.1.1.0/24 1.1.1.2 1 0 RAOF 19
10.2.1.0/24 1.1.1.2 1 0 RAOF 19
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
1.1.1.0/24 0.0.0.0 0 0 RDOF -
2.1.1.0/24 0.0.0.0 0 0 RDOF -
3.1.1.0/24 0.0.0.0 0 0 RDOF -
The output shows that RIPv2 uses classless subnet masks.
NOTE:
After RIPv2 is configured, RIPv1 routes might still exist in the routing table until they are aged out.
# Display the RIP routing table on Device B.
[DeviceB] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.1 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
2.1.1.0/24 1.1.1.1 1 0 RAOF 19
3.1.1.0/24 1.1.1.1 1 0 RAOF 19
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
1.1.1.0/24 0.0.0.0 0 0 RDOF -
10.1.1.0/24 0.0.0.0 0 0 RDOF -
10.2.1.0/24 0.0.0.0 0 0 RDOF -
4. Configure RIP route filtering:
# Use IP prefix lists on Device B to filter received and redistributed routes.
[DeviceB] ip prefix-list aaa index 10 permit 2.1.1.0 24
[DeviceB] ip prefix-list bbb index 10 deny 10.2.1.0 24
[DeviceB] ip prefix-list bbb index 11 permit 0.0.0.0 0 less-equal 32
[DeviceB] rip 1
[DeviceB-rip-1] filter-policy prefix-list aaa import
[DeviceB-rip-1] filter-policy prefix-list bbb export
[DeviceB-rip-1] quit
# Display the RIP routing table on Device A.
[DeviceA] display rip 1 route
Route Flags: R - RIP, T - TRIP
56
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
10.1.1.0/24 1.1.1.2 1 0 RAOF 19
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
1.1.1.0/24 0.0.0.0 0 0 RDOF -
2.1.1.0/24 0.0.0.0 0 0 RDOF -
3.1.1.0/24 0.0.0.0 0 0 RDOF -
# Display the RIP routing table on Device B.
[DeviceB] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.1 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
2.1.1.0/24 1.1.1.1 1 0 RAOF 19
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
1.1.1.0/24 0.0.0.0 0 0 RDOF -
10.1.1.0/24 0.0.0.0 0 0 RDOF -
10.2.1.0/24 0.0.0.0 0 0 RDOF -
Example: Configuring RIP route redistribution
Network configuration
As shown in Figure 9 , Device B communicates with Device A through RIP 100 and with Device C
through RIP 200.
Configure RIP 200 to redistribute direct routes and routes from RIP 100 on Device B so Device C can learn routes destined for 10.2.1.0/24 and 11.1.1.0/24. Device A cannot learn routes destined for
12.3.1.0/24 and 16.4.1.0/24.
Figure 9 Network diagram
RIP 100 RIP 200
HGE1/0/1
10.2.1.1/24
Device A
HGE1/0/2
11.1.1.1/24
HGE1/0/2
11.1.1.2/24
Devcie B
HGE1/0/1
12.3.1.1/24
HGE1/0/1
12.3.1.2/24
Device C
HGE1/0/2
16.4.1.1/24
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
57
1. Configure IP addresses for the interfaces. (Details not shown.)
2. Configure basic RIP settings:
# Enable RIP 100, and configure RIPv2 on Device A.
<DeviceA> system-view
[DeviceA] rip 100
[DeviceA-rip-100] network 10.0.0.0
[DeviceA-rip-100] network 11.0.0.0
[DeviceA-rip-100] version 2
[DeviceA-rip-100] undo summary
[DeviceA-rip-100] quit
# Enable RIP 100 and RIP 200, and configure RIPv2 on Device B.
<DeviceB> system-view
[DeviceB] rip 100
[DeviceB-rip-100] network 11.0.0.0
[DeviceB-rip-100] version 2
[DeviceB-rip-100] undo summary
[DeviceB-rip-100] quit
[DeviceB] rip 200
[DeviceB-rip-200] network 12.0.0.0
[DeviceB-rip-200] version 2
[DeviceB-rip-200] undo summary
[DeviceB-rip-200] quit
# Enable RIP 200, and configure RIPv2 on Device C.
<DeviceC> system-view
[DeviceC] rip 200
[DeviceC-rip-200] network 12.0.0.0
[DeviceC-rip-200] network 16.0.0.0
[DeviceC-rip-200] version 2
[DeviceC-rip-200] undo summary
[DeviceC-rip-200] quit
# Display the IP routing table on Device C.
[DeviceC] display ip routing-table
Destinations : 16 Routes : 16
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
12.3.1.0/24 Direct 0 0 12.3.1.2 HGE1/0/1
12.3.1.0/32 Direct 0 0 12.3.1.2 HGE1/0/1
12.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0
12.3.1.255/32 Direct 0 0 12.3.1.2 HGE1/0/1
16.4.1.0/24 Direct 0 0 16.4.1.1 HGE1/0/2
16.4.1.0/32 Direct 0 0 16.4.1.1 HGE1/0/2
16.4.1.1/32 Direct 0 0 127.0.0.1 InLoop0
16.4.1.255/32 Direct 0 0 16.4.1.1 HGE1/0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
58
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
3. Configure RIP route redistribution:
# Configure RIP 200 to redistribute direct routes and routes from RIP 100 on Device B.
[DeviceB] rip 200
[DeviceB-rip-200] import-route rip 100
[DeviceB-rip-200] import-route direct
[DeviceB-rip-200] quit
# Display the IP routing table on Device C.
[DeviceC] display ip routing-table
Destinations : 15 Routes : 15
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.2.1.0/24 RIP 100 1 12.3.1.1 HGE1/0/1
11.1.1.0/24 RIP 100 1 12.3.1.1 HGE1/0/1
12.3.1.0/24 Direct 0 0 12.3.1.2 HGE1/0/1
12.3.1.0/32 Direct 0 0 12.3.1.2 HGE1/0/1
12.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0
12.3.1.255/32 Direct 0 0 12.3.1.2 HGE1/0/1
16.4.1.0/24 Direct 0 0 16.4.1.1 HGE1/0/2
16.4.1.0/32 Direct 0 0 16.4.1.1 HGE1/0/2
16.4.1.1/32 Direct 0 0 127.0.0.1 InLoop0
16.4.1.255/32 Direct 0 0 16.4.1.1 HGE1/0/2
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
Example: Configuring an additional metric for a RIP interface
Network configuration
As shown in Figure 10 , run RIPv2 on all the interfaces of Device A, Device B, Device C, Device D,
and Device E.
Device A has two links to Device D. The link from Device B to Device D is more stable than that from
Device C to Device D. Configure an additional metric for RIP routes received from HundredGigE
1/0/2 on Device A so Device A prefers route 1.1.5.0/24 learned from Device B.
59
Figure 10 Network diagram
Device A
HGE1/0/1
1.1.1.1/24
HGE1/0/2
1.1.2.1/24
HGE1/0/1
1.1.1.2/24
Device B
HGE1/0/2
1.1.3.1/24
HGE1/0/1
1.1.4.2/24
HGE1/0/2
1.1.3.2/24
Device D
HGE1/0/3
1.1.5.1/24
HGE1/0/1
1.1.5.2/24
Device E
HGE1/0/1
1.1.2.2/24
HGE1/0/2
1.1.4.1/24
Device C
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for the the interfaces. (Details not shown.)
2. Configure basic RIP settings:
# Configure Device A.
<DeviceA> system-view
[DeviceA] rip
[DeviceA-rip-1] network 1.0.0.0
[DeviceA-rip-1] version 2
[DeviceA-rip-1] undo summary
[DeviceA-rip-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] rip
[DeviceB-rip-1] network 1.0.0.0
[DeviceB-rip-1] version 2
[DeviceB-rip-1] undo summary
# Configure Device C.
<DeviceC> system-view
[DeviceC] rip
[DeviceC-rip-1] network 1.0.0.0
[DeviceC-rip-1] version 2
[DeviceC-rip-1] undo summary
# Configure Device D.
<DeviceD> system-view
[DeviceD] rip
[DeviceD-rip-1] network 1.0.0.0
[DeviceD-rip-1] version 2
[DeviceD-rip-1] undo summary
# Configure Device E.
<DeviceE> system-view
[DeviceE] rip
[DeviceE-rip-1] network 1.0.0.0
[DeviceE-rip-1] version 2
60
[DeviceE-rip-1] undo summary
# Display all active routes in the RIP database on Device A.
[DeviceA] display rip 1 database
1.0.0.0/8, auto-summary
1.1.1.0/24, cost 0, nexthop 1.1.1.1, RIP-interface
1.1.2.0/24, cost 0, nexthop 1.1.2.1, RIP-interface
1.1.3.0/24, cost 1, nexthop 1.1.1.2
1.1.4.0/24, cost 1, nexthop 1.1.2.2
1.1.5.0/24, cost 2, nexthop 1.1.1.2
1.1.5.0/24, cost 2, nexthop 1.1.2.2
The output shows two RIP routes destined for network 1.1.5.0/24. The next hops of the routes are Device B (1.1.1.2) and Device C (1.1.2.2). The cost of the routes is 2.
3. Configure an additional metric for a RIP interface:
# Configure an inbound additional metric of 3 for RIP-enabled interface HundredGigE 1/0/2.
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] rip metricin 3
# Display all active routes in the RIP database on Device A.
[DeviceA-HundredGigE1/0/2] display rip 1 database
1.0.0.0/8, auto-summary
1.1.1.0/24, cost 0, nexthop 1.1.1.1, RIP-interface
1.1.2.0/24, cost 0, nexthop 1.1.2.1, RIP-interface
1.1.3.0/24, cost 1, nexthop 1.1.1.2
1.1.4.0/24, cost 2, nexthop 1.1.1.2
1.1.5.0/24, cost 2, nexthop 1.1.1.2
The output shows that only one RIP route reaches network 1.1.5.0/24, with the next hop as
Device B (1.1.1.2) and a cost of 2.
Example: Configuring RIP to advertise a summary route
Network configuration
As shown in Figure 11 , Device A and Device B run OSPF, Device D runs RIP, and Device C runs
OSPF and RIP.
•
Configure RIP to redistribute OSPF routes on Device C so Device D can learn routes destined for networks 10.1.1.0/24, 10.2.1.0/24, 10.5.1.0/24, and 10.6.1.0/24.
•
To reduce the routing table size of Device D, configure route summarization on Device C to advertise only the summary route 10.0.0.0/8 to Device D.
61
Figure 11 Network diagram
HGE1/0/1
10.1.1.1/24
HGE1/0/2
10.6.1.2/24
HGE1/0/2
11.3.1.1/24
HGE1/0/3
10.1.1.2/24
HGE1/0/1
10.2.1.2/24
HGE1/0/1
Device C
10.2.1.1/24
Device B
Device A
HGE1/0/2
10.5.1.2/24
OSPF
RIP
HGE1/0/2
11.4.1.2/24
Device D
HGE1/0/1
11.3.1.2/24
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for the interfaces. (Details not shown.)
2. Configure basic OSPF settings:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 10.5.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] network 10.6.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
3. Configure basic RIP settings:
# Configure Device C.
[DeviceC] rip 1
[DeviceC-rip-1] network 11.3.1.0
[DeviceC-rip-1] version 2
[DeviceC-rip-1] undo summary
62
# Configure Device D.
<DeviceD> system-view
[DeviceD] rip 1
[DeviceD-rip-1] network 11.0.0.0
[DeviceD-rip-1] version 2
[DeviceD-rip-1] undo summary
[DeviceD-rip-1] quit
# Configure RIP to redistribute routes from OSPF process 1 and direct routes on Device C.
[DeviceC-rip-1] import-route direct
[DeviceC-rip-1] import-route ospf 1
[DeviceC-rip-1] quit
# Display the IP routing table on Device D.
[DeviceD] display ip routing-table
Destinations : 15 Routes : 15
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.1.1.0/24 RIP 100 1 11.3.1.1 HGE1/0/1
10.2.1.0/24 RIP 100 1 11.3.1.1 HGE1/0/1
10.5.1.0/24 RIP 100 1 11.3.1.1 HGE1/0/1
10.6.1.0/24 RIP 100 1 11.3.1.1 HGE1/0/1
11.3.1.0/24 Direct 0 0 11.3.1.2 HGE1/0/1
11.3.1.0/32 Direct 0 0 11.3.1.2 HGE1/0/1
11.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.4.1.0/24 Direct 0 0 11.4.1.2 HGE1/0/2
11.4.1.0/32 Direct 0 0 11.4.1.2 HGE1/0/2
11.4.1.2/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
4. Configure route summarization:
# Configure route summarization on Device C to advertise only the summary route 10.0.0.0/8.
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] rip summary-address 10.0.0.0 8
# Display the IP routing table on Device D.
[DeviceD] display ip routing-table
Destinations : 12 Routes : 12
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/8 RIP 100 1 11.3.1.1 HGE1/0/1
11.3.1.0/24 Direct 0 0 11.3.1.2 HGE1/0/1
11.3.1.0/32 Direct 0 0 11.3.1.2 HGE1/0/1
11.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.4.1.0/24 Direct 0 0 11.4.1.2 HGE1/0/2
63
11.4.1.0/32 Direct 0 0 11.4.1.2 HGE1/0/2
11.4.1.2/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
Example: Configuring RIP GR
Network configuration
As shown in Figure 12 , Device A, Device B, and Device C run RIPv2.
•
Enable GR on Device A. Device A acts as the GR restarter.
•
Device B and Device C act as GR helpers to synchronize their routing tables with Device A by using GR.
Figure 12 Network diagram
Router ID: 1.1.1.1
GR restarter
Device A
HGE1/0/1
192.1.1.1/24
HGE1/0/1
192.1.1.2/24
Device B
GR helper
Router ID: 2.2.2.2
Procedure
HGE1/0/1
192.1.1.3/24
Device C
GR helper
Router ID: 3.3.3.3
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses and subnet masks for the interfaces on the devices. (Details not shown.)
2. Configure RIPv2 on the devices to ensure the following: (Details not shown.)
Device A, Device B, and Device C can communicate with each other at Layer 3.
Dynamic route update can be implemented among them with RIPv2.
3. Enable RIP GR on Device A.
<DeviceA> system-view
[DeviceA] rip
[DeviceA-rip-1] graceful-restart
Verifying the configuration
# Restart RIP or trigger an active/standby process switchover, and then display GR status on Device
A.
<DeviceA> display rip graceful-restart
64
RIP process: 1
Graceful Restart capability : Enabled
Current GR state : Normal
Graceful Restart period : 60 seconds
Graceful Restart remaining time : 0 seconds
Example: Configuring RIP NSR
Network configuration
As shown in Figure 13 , Device A, Device B, and Device S all run RIPv2.
Enable RIP NSR on Device S to ensure correct routing when an active/standby switchover occurs on
Device S.
Figure 13 Network diagram
Loop 0
22.22.22.22/32
Device A
HGE1/0/1
12.12.12.1/24
HGE1/0/1
12.12.12.2/24
Device S
HGE1/0/1
14.14.14.1/24
HGE1/0/2
14.14.14.2/24
Device B
Loop 0
44.44.44.44/32
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses and subnet masks for the interfaces on the devices. (Details not shown.)
2. Configure RIPv2 on the devices to ensure the following: (Details not shown.)
Device A, Device B, and Device S can communicate with each other at Layer 3.
Dynamic route update can be implemented among them with RIPv2.
3. Enable RIP NSR on Device S.
<DeviceS> system-view
[DeviceS] rip 100
[DeviceS-rip-100] non-stop-routing
[DeviceS-rip-100] quit
Verifying the configuration
# Perform an active/standby switchover on Device S.
[DeviceS] placement reoptimize
Predicted changes to the placement
Program Current location New location
--------------------------------------------------------------------- lb 0/0 0/0 lsm 0/0 0/0 slsp 0/0 0/0 rib6 0/0 0/0 routepolicy 0/0 0/0 rib 0/0 0/0 staticroute6 0/0 0/0
65
staticroute 0/0 0/0 rip 0/0 1/0
Continue? [y/n]:y
Re-optimization of the placement start. You will be notified on completion
Re-optimization of the placement complete. Use 'display placement' to view the new placement
# Display neighbor information and route information on Device A.
[DeviceA] display rip 1 neighbor
Neighbor Address: 12.12.12.2
Interface : HundredGigE1/0/1
Version : RIPv2 Last update: 00h00m13s
Relay nbr : No BFD session: None
Bad packets: 0 Bad routes : 0
[DeviceA] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 12.12.12.2 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
14.0.0.0/8 12.12.12.2 1 0 RAOF 16
44.0.0.0/8 12.12.12.2 2 0 RAOF 16
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
12.12.12.0/24 0.0.0.0 0 0 RDOF -
22.22.22.22/32 0.0.0.0 0 0 RDOF -
# Display neighbor information and route information on Device B.
[DeviceB] display rip 1 neighbor
Neighbor Address: 14.14.14.2
Interface : HundredGigE1/0/1
Version : RIPv2 Last update: 00h00m32s
Relay nbr : No BFD session: None
Bad packets: 0 Bad routes : 0
[DeviceB] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
D - Direct, O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 14.14.14.2 on HundredGigE1/0/1
Destination/Mask Nexthop Cost Tag Flags Sec
12.0.0.0/8 14.14.14.2 1 0 RAOF 1
22.0.0.0/8 14.14.14.2 2 0 RAOF 1
Local route
Destination/Mask Nexthop Cost Tag Flags Sec
44.44.44.44/32 0.0.0.0 0 0 RDOF -
14.14.14.0/24 0.0.0.0 0 0 RDOF -
66
The output shows that the neighbor and route information on Device A and Device B keep unchanged during the active/standby switchover on Device S. The traffic from Device A to Device B has not been impacted.
Example: Configuring BFD for RIP (single-hop echo detection for a directly connected neighbor)
Network configuration
As shown in
Figure 14 , HundredGigE 1/0/1 of Device A and Device C runs RIP process 1.
HundredGigE 1/0/2 of Device A runs RIP process 2. HundredGigE 1/0/2 of Device C and
HundredGigE 1/0/1 and HundredGigE 1/0/2 of Device B run RIP process 1.
•
Configure a static route destined for 100.1.1.1/24 and enable static route redistribution into RIP on Device C. This allows Device A to learn two routes destined for 100.1.1.1/24 through
HundredGigE 1/0/1 and HundredGigE 1/0/2 respectively, and uses the one through
HundredGigE 1/0/1.
•
Enable BFD for RIP on HundredGigE 1/0/1 of Device A. When the link over HundredGigE 1/0/1 fails, BFD can quickly detect the failure and notify RIP. RIP deletes the neighbor relationship and route information learned on HundredGigE 1/0/1, and uses the route destined for 100.1.1.1
24 through HundredGigE 1/0/2.
Figure 14 Network diagram
Device B
HGE1/0/1
192.168.2.2/24
HGE1/0/2
192.168.3.1/24
HGE1/0/2
192.168.2.1/24
HGE1/0/1
192.168.1.1/24
Switch
HGE1/0/1
192.168.1.2/24
HGE1/0/2
192.168.3.2/24
Device A BFD Device C
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure basic RIP settings and enable BFD on the interfaces:
# Configure Device A.
<DeviceA> system-view
[DeviceA] rip 1
[DeviceA-rip-1] version 2
[DeviceA-rip-1] undo summary
[DeviceA-rip-1] network 192.168.1.0
[DeviceA-rip-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] rip bfd enable
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] rip 2
67
[DeviceA-rip-2] network 192.168.2.0
[DeviceA-rip-2] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] rip 1
[DeviceB-rip-1] version 2
[DeviceB-rip-1] undo summary
[DeviceB-rip-1] network 192.168.2.0
[DeviceB-rip-1] network 192.168.3.0
[DeviceB-rip-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] rip 1
[DeviceC-rip-1] version 2
[DeviceC-rip-1] undo summary
[DeviceC-rip-1] network 192.168.1.0
[DeviceC-rip-1] network 192.168.3.0
[DeviceC-rip-1] import-route static
[DeviceC-rip-1] quit
2. Configure the BFD parameters on HundredGigE 1/0/1 of Device A.
[DeviceA] bfd echo-source-ip 11.11.11.11
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] bfd min-echo-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 7
[DeviceA-HundredGigE1/0/1] quit
3. Configure a static route on Device C.
[DeviceC] ip route-static 120.1.1.1 24 null 0
Verifying the configuration
# Display the BFD session information on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working in echo mode:
LD SourceAddr DestAddr State Holdtime Interface
4 192.168.1.1 192.168.1.2 Up 2000ms HGE1/0/1
# Display RIP routes destined for 120.1.1.0/24 on Device A.
<DeviceA> display ip routing-table 120.1.1.0 24
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 RIP 100 1 192.168.1.2 HGE1/0/1
The output shows that Device A communicates with Device C through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display RIP routes destined for 120.1.1.0/24 on Device A.
68
<DeviceA> display ip routing-table 120.1.1.0 24
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
120.1.1.0/24 RIP 100 2 192.168.2.2 HGE1/0/2
The output shows that Device A communicates with Device C through HundredGigE 1/0/2.
Example: Configuring BFD for RIP (single-hop echo detection for a specific destination)
Network configuration
As shown in Figure 15 , HundredGigE 1/0/2 of Device A and HundredGigE 1/0/1 of Device B run RIP
process 1. HundredGigE 1/0/2 of Device B and Device C runs RIP process 1.
•
Configure a static route destined for 100.1.1.0/24 and enable static route redistribution into RIP on both Device A and Device C. This allows Device B to learn two routes destined for
100.1.1.0/24 through HundredGigE 1/0/1 and HundredGigE 1/0/2. The route redistributed from
Device A has a smaller cost than that redistributed from Device C, so Device B uses the route through HundredGigE 1/0/1.
•
Enable BFD for RIP on HundredGigE 1/0/2 of Device A, and specify HundredGigE 1/0/1 of
Device B as the destination. When a unidirectional link occurs between Device A and Device B,
BFD can quickly detect the link failure and notify RIP. RIP then deletes the neighbor relationship and the route information learned on HundredGigE 1/0/2. It does not receive or send any packets on HundredGigE 1/0/2. When the route learned from Device A ages out, Device B uses the route destined for 100.1.1.1/24 through HundredGigE 1/0/2.
Figure 15 Network diagram
Device B
HGE1/0/1
192.168.2.2/24
HGE1/0/2
192.168.3.1/24
HGE1/0/2
192.168.2.1/24
HGE1/0/2
192.168.3.2/24
Device A
RIP packets
BFD session
Fault
Device C
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP settings and enable BFD on the interfaces:
# Configure Device A.
<DeviceA> system-view
69
[DeviceA] rip 1
[DeviceA-rip-1] network 192.168.2.0
[DeviceA-rip-1] import-route static
[DeviceA-rip-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] rip bfd enable destination 192.168.2.2
[DeviceA-HundredGigE1/0/2] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] rip 1
[DeviceB-rip-1] network 192.168.2.0
[DeviceB-rip-1] network 192.168.3.0
[DeviceB-rip-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] rip 1
[DeviceC-rip-1] network 192.168.3.0
[DeviceC-rip-1] import-route static cost 3
[DeviceC-rip-1] quit
3. Configure BFD parameters on HundredGigE 1/0/2 of Device A.
[DeviceA] bfd echo-source-ip 11.11.11.11
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] bfd min-echo-receive-interval 500
[DeviceA-HundredGigE1/0/2] quit
4. Configure static routes:
# Configure a static route on Device A.
[DeviceA] ip route-static 100.1.1.0 24 null 0
# Configure a static route on Device C.
[DeviceC] ip route-static 100.1.1.0 24 null 0
Verifying the configuration
# Display the BFD session information on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working in echo mode:
LD SourceAddr DestAddr State Holdtime Interface
3 192.168.2.1 192.168.2.2 Up 2000ms HGE1/0/2
# Display routes destined for 100.1.1.0/24 on Device B.
<DeviceB> display ip routing-table 100.1.1.0 24 verbose
Summary count : 1
Destination: 100.1.1.0/24
Protocol: RIP
Process ID: 1
70
SubProtID: 0x1 Age: 00h02m47s
Cost: 1 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x12000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.2.1
Flags: 0x1008c OrigNextHop: 192.168.2.1
Label: NULL RealNextHop: 192.168.2.1
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display routes destined for 100.1.1.0/24 on Device B when the link between Device A and Device
B fails.
<DeviceB> display ip routing-table 100.1.1.0 24 verbose
Summary count : 1
Destination: 100.1.1.0/24
Protocol: RIP
Process ID: 1
SubProtID: 0x1 Age: 00h21m23s
Cost: 4 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x12000003 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.3.2
Flags: 0x1008c OrigNextHop: 192.168.3.2
Label: NULL RealNextHop: 192.168.3.2
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
71
VpnPeerId: N/A Dscp: N/A
Example: Configuring BFD for RIP (bidirectional control detection)
Network configuration
As shown in Figure 16 , HundredGigE 1/0/2 of Device A and HundredGigE 1/0/1 of Device C run RIP
process 1. HundredGigE 1/0/1 on Device A runs RIP process 2. HundredGigE 1/0/2 on Device C, and HundredGigE 1/0/1 and HundredGigE 1/0/2 on Device D run RIP process 1.
•
Configure a static route destined for 100.1.1.0/24 on Device A.
•
Configure a static route destined for 101.1.1.0/24 on Device C.
•
Enable static route redistribution into RIP on Device A and Device C. This allows Device A to learn two routes destined for 100.1.1.0/24 through HundredGigE 1/0/2 and HundredGigE 1/0/1.
It uses the route through HundredGigE 1/0/2.
•
Enable BFD for RIP on HundredGigE 1/0/2 of Device A and HundredGigE 1/0/1 of Device C.
When the link over HundredGigE 1/0/2 fails, BFD can quickly detect the link failure and notify RIP.
RIP deletes the neighbor relationship and the route information learned on HundredGigE 1/0/2, and uses the route destined for 100.1.1.0/24 through HundredGigE 1/0/1.
Figure 16 Network diagram
Device D
HGE1/0/1 HGE1/0/2
101.1.1.0/24
HGE1/0/1
HGE1/0/2
HGE1/0/2
Device B
HGE1/0/1
HGE1/0/2
HGE1/0/1
100.1.1.0/24
Device A
BFD
Device C
Table 7 Interface and IP address assignment
Device
Device A
Device A
Device B
Device B
Device C
Device C
Device D
Device D
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
192.168.3.1/24
192.168.1.1/24
192.168.2.1/24
192.168.1.2/24
192.168.2.2/24
192.168.4.2/24
192.168.3.2/24
192.168.4.1/24
72
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for the interfaces. (Details not shown.)
2. Configure basic RIP settings and enable static route redistribution into RIP so Device A and
Device C have routes to send to each other:
# Configure Device A.
<DeviceA> system-view
[DeviceA] rip 1
[DeviceA-rip-1] version 2
[DeviceA-rip-1] undo summary
[DeviceA-rip-1] network 192.168.1.0
[DeviceA-rip-1] network 101.1.1.0
[DeviceA-rip-1] peer 192.168.2.2
[DeviceA-rip-1] undo validate-source-address
[DeviceA-rip-1] import-route static
[DeviceA-rip-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] rip bfd enable
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] rip 2
[DeviceA-rip-2] version 2
[DeviceA-rip-2] undo summary
[DeviceA-rip-2] network 192.168.3.0
[DeviceA-rip-2] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] rip 1
[DeviceC-rip-1] version 2
[DeviceC-rip-1] undo summary
[DeviceC-rip-1] network 192.168.2.0
[DeviceC-rip-1] network 192.168.4.0
[DeviceC-rip-1] network 100.1.1.0
[DeviceC-rip-1] peer 192.168.1.1
[DeviceC-rip-1] undo validate-source-address
[DeviceC-rip-1] import-route static
[DeviceC-rip-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] rip bfd enable
[DeviceC-HundredGigE1/0/1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] rip 1
[DeviceD-rip-1] version 2
[DeviceD-rip-1] undo summary
[DeviceD-rip-1] network 192.168.3.0
73
[DeviceD-rip-1] network 192.168.4.0
[DeviceD-rip-1] quit
3. Configure BFD parameters for the interfaces:
# Configure Device A.
[DeviceA] bfd session init-mode active
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ip address 192.168.3.1 24
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ip address 192.168.1.1 24
[DeviceA-HundredGigE1/0/2] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/2] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/2] bfd detect-multiplier 7
[DeviceA-HundredGigE1/0/2] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ip address 192.168.1.2 24
[DeviceB-HundredGigE1/0/2] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ip address 192.168.2.1 24
# Configure Device C.
[DeviceC] bfd session init-mode active
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ip address 192.168.2.2 24
[DeviceC-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceC-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceC-HundredGigE1/0/1] bfd detect-multiplier 6
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ip address 192.168.4.2 24
[DeviceC-HundredGigE1/0/2] quit
# Configure Device D.
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] ip address 192.168.4.1 24
[DeviceD-HundredGigE1/0/2] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] ip address 192.168.3.2 24
[DeviceD-HundredGigE1/0/1] quit
4. Configure static routes:
# Configure a static route to Device C on Device A.
[DeviceA] ip route-static 192.168.2.0 24 hundredgige 1/0/2 192.168.1.2
[DeviceA] quit
# Configure a static route to Device A on Device C.
[DeviceC] ip route-static 192.168.1.0 24 hundredgige 1/0/1 192.168.2.1
Verifying the configuration
# Display the BFD session information on Device A.
74
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
513/513 192.168.1.1 192.168.2.2 Up 1700ms HGE1/0/2
# Display RIP routes destined for 100.1.1.0/24 learned on Device A.
<DeviceA> display ip routing-table 100.1.1.0 24
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
100.1.1.0/24 RIP 100 1 192.168.2.2 HGE1/0/2
The output shows that Device A communicates with Device C through HundredGigE 1/0/2. Then the link over HundredGigE 1/0/2 fails.
# Display RIP routes destined for 100.1.1.0/24 on Device A.
<DeviceA> display ip routing-table 100.1.1.0
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
100.1.1.0/24 RIP 100 2 192.168.3.2 HGE1/0/1
The output shows that Device A communicates with Device C through HundredGigE 1/0/1.
Example: Configuring RIP FRR
Network configuration
As shown in Figure 17 , Device A, Device B, and Device C run RIPv2. Configure RIP FRR so that
when Link A becomes unidirectional, traffic can be switched to Link B immediately.
Figure 17 Network diagram
Device C
HGE
1/0
/1
HGE
1/0
/2
Link B
HGE
1/0
/1
Link A
Loop0
HGE1/0/2
Device A
Table 8 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Device A
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
12.12.12.1/24
13.13.13.1/24
75
Device
Device A
Device B
Device B
Device B
Device C
Device C
Procedure
Interface
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
1.1.1.1/32
24.24.24.4/24
13.13.13.2/24
4.4.4.4/32
12.12.12.2/24
24.24.24.2/24
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses and subnet masks for the interfaces on the devices. (Details not shown.)
2. Configure RIPv2 on the devices to make sure Device A, Device B, and Device C can communicate with each other at the network layer. (Details not shown.)
3. Configure RIP FRR:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ip prefix-list abc index 10 permit 4.4.4.4 32
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ip address prefix-list abc
[DeviceA-route-policy-frr-10] apply fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 12.12.12.2
[DeviceA-route-policy-frr-10] quit
[DeviceA] rip 1
[DeviceA-rip-1] fast-reroute route-policy frr
[DeviceA-rip-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ip prefix-list abc index 10 permit 1.1.1.1 32
[DeviceB] route-policy frr permit node 10
[DeviceB-route-policy-frr-10] if-match ip address prefix-list abc
[DeviceB-route-policy-frr-10] apply fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 24.24.24.2
[DeviceB-route-policy-frr-10] quit
[DeviceB] rip 1
[DeviceB-rip-1] fast-reroute route-policy frr
[DeviceB-rip-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Device A to view the backup next hop information.
[DeviceA] display ip routing-table 4.4.4.4 verbose
Destination: 4.4.4.4/32
Protocol: RIP
76
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 13.13.13.2
Flags: 0x1008c OrigNextHop: 13.13.13.2
Label: NULL RealNextHop: 13.13.13.2
BkLabel: NULL BkNextHop: 12.12.12.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display route 1.1.1.1/32 on Device B to view the backup next hop information.
[DeviceB] display ip routing-table 1.1.1.1 verbose
Summary count : 1
Destination: 1.1.1.1/32
Protocol: RIP
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 13.13.13.1
Flags: 0x1008c OrigNextHop: 13.13.13.1
Label: NULL RealNextHop: 13.13.13.1
BkLabel: NULL BkNextHop: 24.24.24.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
77
VpnPeerId: N/A Dscp: N/A
78
Configuring OSPF
About OSPF
Open Shortest Path First (OSPF) is a link-state IGP developed by the OSPF working group of the
IETF. OSPF version 2 is used for IPv4. OSPF refers to OSPFv2 throughout this chapter.
OSPF features
OSPF has the following features:
•
Wide scope —Supports multiple network sizes and several hundred routers in an OSPF routing domain.
•
Fast convergence —Advertises routing updates instantly upon network topology changes.
•
Loop free —Computes routes with the SPF algorithm to avoid routing loops.
•
Area-based network partition —Splits an AS into multiple areas to facilitate management.
This feature reduces the LSDB size on routers to save memory and CPU resources, and reduces route updates transmitted between areas to save bandwidth.
•
ECMP routing —Supports multiple equal-cost routes to a destination.
•
Routing hierarchy —Supports a 4-level routing hierarchy that prioritizes routes into intra-area, inter-area, external Type-1, and external Type-2 routes.
•
Authentication —Supports area- and interface-based packet authentication to ensure secure packet exchange.
•
Support for multicasting —Multicasts protocol packets on some types of links to avoid impacting other devices.
OSPF packets
OSPF messages are carried directly over IP. The protocol number is 89.
OSPF uses the following packet types:
•
Hello —Periodically sent to find and maintain neighbors, containing timer values, information about the DR, BDR, and known neighbors.
•
Database description (DD) —Describes the digest of each LSA in the LSDB, exchanged between two routers for data synchronization.
•
Link state request (LSR) —Requests needed LSAs from a neighbor. After exchanging the DD packets, the two routers know which LSAs of the neighbor are missing from their LSDBs. They then exchange LSR packets requesting the missing LSAs. LSR packets contain the digest of the missing LSAs.
•
Link state update (LSU) —Transmits the requested LSAs to the neighbor.
•
Link state acknowledgment (LSAck) —Acknowledges received LSU packets. It contains the headers of received LSAs (an LSAck packet can acknowledge multiple LSAs).
LSA types
OSPF advertises routing information in Link State Advertisements (LSAs). The following LSAs are commonly used:
79
•
Router LSA —Type-1 LSA, originated by all routers and flooded throughout a single area only.
This LSA describes the collected states of the router's interfaces to an area.
•
Network LSA —Type-2 LSA, originated for broadcast and NBMA networks by the designated router, and flooded throughout a single area only. This LSA contains the list of routers connected to the network.
•
Network Summary LSA —Type-3 LSA, originated by Area Border Routers (ABRs), and flooded throughout the LSA's associated area. Each summary-LSA describes a route to a destination outside the area, yet still inside the AS (an inter-area route).
•
ASBR Summary LSA —Type-4 LSA, originated by ABRs and flooded throughout the LSA's associated area. Type 4 summary-LSAs describe routes to Autonomous System Boundary
Router (ASBR).
•
AS External LSA —Type-5 LSA, originated by ASBRs, and flooded throughout the AS (except stub and NSSA areas). Each AS-external-LSA describes a route to another AS.
•
NSSA LSA —Type-7 LSA, as defined in RFC 1587, originated by ASBRs in NSSAs and flooded throughout a single NSSA. NSSA LSAs describe routes to other ASs.
•
Opaque LSA —A proposed type of LSA. Its format consists of a standard LSA header and application specific information. Opaque LSAs are used by the OSPF protocol or by some applications to distribute information into the OSPF routing domain. The opaque LSA includes
Type 9, Type 10, and Type 11. The Type 9 opaque LSA is flooded into the local subnet, the Type
10 is flooded into the local area, and the Type 11 is flooded throughout the AS.
OSPF areas
Area-based OSPF network partition
In large OSPF routing domains, SPF route computations consume too many storage and CPU resources, and enormous OSPF packets generated for route synchronization occupy excessive bandwidth.
To resolve these issues, OSPF splits an AS into multiple areas. Each area is identified by an area ID.
The boundaries between areas are routers rather than links. A network segment (or a link) can only
reside in one area as shown in Figure 18 .
You can configure route summarization on ABRs to reduce the number of LSAs advertised to other areas and minimize the effect of topology changes.
80
Figure 18 Area-based OSPF network partition
Area 4
Area 1
Area 0
Area 2
Area 3
Backbone area
Each AS has a backbone area that distributes routing information between non-backbone areas.
Routing information between non-backbone areas must be forwarded by the backbone area. OSPF has the following requirements:
•
All non-backbone areas must maintain connectivity to the backbone area.
•
The backbone area must maintain connectivity within itself.
In practice, these requirements might not be met due to lack of physical links. OSPF virtual links can solve this issue.
Virtual links
A virtual link is established between two ABRs through a non-backbone area. It must be configured on both ABRs to take effect. The non-backbone area is called a transit area.
As shown in Figure 19 , Area 2 has no direct physical link to the backbone Area 0. You can configure
a virtual link between the two ABRs to connect Area 2 to the backbone area.
Figure 19 Virtual link application 1
Transit area
Virtual link
Area 0
ABR ABR
Area 2
Area 1
Virtual links can also be used as redundant links. If a physical link failure breaks the internal connectivity of the backbone area, you can configure a virtual link to replace the failed physical link,
81
Figure 20 Virtual link application 2
Area 1
Virtual link
R2 R1
Area 0
The virtual link between the two ABRs acts as a point-to-point connection. You can configure interface parameters, such as hello interval, on the virtual link as they are configured on a physical interface.
The two ABRs on the virtual link unicast OSPF packets to each other, and the OSPF routers in between convey these OSPF packets as normal IP packets.
Stub area and totally stub area
A stub area does not distribute Type-5 LSAs to reduce the routing table size and LSAs advertised within the area. The ABR of the stub area advertises a default route in a Type-3 LSA so that the routers in the area can reach external networks through the default route.
To further reduce the routing table size and advertised LSAs, you can configure the stub area as a totally stub area. The ABR of a totally stub area does not advertise inter-area routes or external routes. It advertises a default route in a Type-3 LSA so that the routers in the area can reach external networks through the default route.
NSSA area and totally NSSA area
An NSSA area does not import AS external LSAs (Type-5 LSAs) but can import Type-7 LSAs generated by the NSSA ASBR. The NSSA ABR translates Type-7 LSAs into Type-5 LSAs and advertises the Type-5 LSAs to other areas.
As shown in Figure 21 , the OSPF AS contains Area 1, Area 2, and Area 0. The other two ASs run RIP.
Area 1 is an NSSA area where the ASBR redistributes RIP routes in Type-7 LSAs into Area 1. Upon receiving the Type-7 LSAs, the NSSA ABR translates them to Type-5 LSAs, and advertises the
Type-5 LSAs to Area 0.
The ASBR of Area 2 redistributes RIP routes in Type-5 LSAs into the OSPF routing domain.
However, Area 1 does not receive Type-5 LSAs because it is an NSSA area.
Figure 21 NSSA area
RIP
RIP
NSSA
ASBR
Type 5
Type 5
Area 2 ABR
Type 5
Type 5
Area 0
NSSA
ABR
Type 7
Area 1
NSSA
ASBR
Router types
ABRs, backbone routers, and ASBRs.
82
Figure 22 OSPF router types
RIP
IS-IS
ASBR
Area 1
Area 4
Backbone router
Internal router
Area 0
ABR
Area 2
Area 3
Internal router
All interfaces on an internal router belong to one OSPF area.
ABR
An ABR belongs to more than two areas, one of which must be the backbone area. ABR connects the backbone area to a non-backbone area. An ABR and the backbone area can be connected through a physical or logical link.
Backbone router
No less than one interface of a backbone router must reside in the backbone area. All ABRs and internal routers in Area 0 are backbone routers.
ASBR
An ASBR exchanges routing information with another AS. An ASBR might not reside on the border of the AS. It can be an internal router or an ABR.
Route types
OSPF prioritizes routes into the following route levels:
•
Intra-area route.
•
Inter-area route.
•
Type-1 external route.
•
Type-2 external route.
The intra-area and inter-area routes describe the network topology of the AS. The external routes describe routes to external ASs.
A Type-1 external route has high credibility. The cost of a Type-1 external route = the cost from the router to the corresponding ASBR + the cost from the ASBR to the destination of the external route.
83
A Type-2 external route has low credibility. OSPF considers that the cost from the ASBR to the destination of a Type-2 external route is much greater than the cost from the ASBR to an OSPF internal router. The cost of a Type-2 external route = the cost from the ASBR to the destination of the
Type-2 external route. If two Type-2 routes to the same destination have the same cost, OSPF takes the cost from the router to the ASBR into consideration to determine the best route.
Router ID
A router ID uniquely identifies a router in an AS. For a router to run OSPF, it must have a router ID.
You can choose to manually specify a router ID, automatically obtain a router ID, or use the global router ID for an OSPF process.
Manual configuration
When you create an OSPF process, you can manually specify a router ID. To make sure the router
ID is unique in the AS, you can specify the IP address of an interface on the router as the router ID.
Automatic configuration
When you create an OSPF process, you can enable the OSPF process to automatically obtain a router ID. The OSPF process obtains a router ID in the following ways:
•
During the startup of the OSPF process, the primary IPv4 address of the first interface that runs the process is specified as the router ID.
•
During the reboot of the router, the primary IPv4 address of the first interface that runs the process is specified as the router ID.
•
During the restart of the OSPF process, the highest primary IPv4 address of the loopback interface that runs the process is specified as the router ID. If no loopback address is available, the highest primary IPv4 address of the interface that runs the process is used, regardless of the interface state (up or down).
Using the global router ID
If you do not specify a router ID when creating an OSPF process, the global router ID is used. As a best practice, manually specify a router ID or enable the OSPF process to automatically obtain a router ID when you create the OSPF process.
Route calculation
OSPF computes routes in an area as follows:
•
Each router generates LSAs based on the network topology around itself, and sends them to other routers in update packets.
•
Each OSPF router collects LSAs from other routers to compose an LSDB. An LSA describes the network topology around a router, and the LSDB describes the entire network topology of the area.
•
Each router transforms the LSDB to a weighted directed graph that shows the topology of the area. All the routers within the area have the same graph.
•
Each router uses the SPF algorithm to compute a shortest path tree that shows the routes to the nodes in the area. The router itself is the root of the tree.
OSPF network types
OSPF classifies networks into the following types, depending on different link layer protocols:
•
Broadcast —If the link layer protocol is Ethernet or FDDI, OSPF considers the network type as broadcast by default. On a broadcast network, hello, LSU, and LSAck packets are multicast to
224.0.0.5 that identifies all OSPF routers or to 224.0.0.6 that identifies the DR and BDR. DD packets and LSR packets are unicast.
84
•
NBMA —If the link layer protocol is Frame Relay, ATM, or X.25, OSPF considers the network type as NBMA by default. OSPF packets are unicast on an NBMA network.
•
P2MP —No link is P2MP type by default. P2MP must be a conversion from other network types such as NBMA. On a P2MP network, OSPF packets are multicast to 224.0.0.5.
•
P2P —If the link layer protocol is PPP or HDLC, OSPF considers the network type as P2P. On a
P2P network, OSPF packets are multicast to 224.0.0.5.
The following are the differences between NBMA and P2MP networks:
•
NBMA networks are fully meshed. P2MP networks are not required to be fully meshed.
•
NBMA networks require DR and BDR election. P2MP networks do not have DR or BDR.
•
On an NBMA network, OSPF packets are unicast, and neighbors are manually configured. On a
P2MP network, OSPF packets are multicast by default, and you can configure OSPF to unicast protocol packets.
DR and BDR
DR and BDR mechanism
On a broadcast or NBMA network, any two routers must establish an adjacency to exchange routing information with each other. If n routers are present on the network, n(n-1)/2 adjacencies are established. Any topology change on the network results in an increase in traffic for route synchronization, which consumes a large amount of system and bandwidth resources.
Using the DR and BDR mechanisms can solve this problem.
•
DR —Elected to advertise routing information among other routers. If the DR fails, routers on the network must elect another DR and synchronize information with the new DR. Using this mechanism without BDR is time-consuming and is prone to route calculation errors.
•
BDR —Elected along with the DR to establish adjacencies with all other routers. If the DR fails, the BDR immediately becomes the new DR, and other routers elect a new BDR.
Routers other than the DR and BDR are called DR Others. They do not establish adjacencies with one another, so the number of adjacencies is reduced.
The role of a router is subnet (or interface) specific. It might be a DR on one interface and a BDR or
DR Other on another interface.
As shown in Figure 23 , solid lines are Ethernet physical links, and dashed lines represent OSPF
adjacencies. With the DR and BDR, only seven adjacencies are established.
Figure 23 DR and BDR in a network
DR BDR
DR other
Physical links
DR other DR other
Adjacencies
85
NOTE:
In OSPF, neighbor and adjacency are different concepts. After startup, OSPF sends a hello packet on each OSPF interface. A receiving router checks parameters in the packet. If the parameters match its own, the receiving router considers the sending router an OSPF neighbor. Two OSPF neighbors establish an adjacency relationship after they synchronize their LSDBs through exchange of DD packets and LSAs.
DR and BDR election
DR election is performed on broadcast or NBMA networks but not on P2P and P2MP networks.
Routers in a broadcast or NBMA network elect the DR and BDR by router priority and ID. Routers with a router priority value higher than 0 are candidates for DR and BDR election.
The election votes are hello packets. Each router sends the DR elected by itself in a hello packet to all the other routers. If two routers on the network declare themselves as the DR, the router with the higher router priority wins. If router priorities are the same, the router with the higher router ID wins.
If a router with a higher router priority becomes active after DR and BDR election, the router cannot replace the DR or BDR until a new election is performed. Therefore, the DR of a network might not be the router with the highest priority, and the BDR might not be the router with the second highest priority.
Protocols and standards
•
RFC 1245, OSPF protocol analysis
•
RFC 1246, Experience with the OSPF protocol
•
RFC 1370, Applicability Statement for OSPF
•
RFC 1403, BGP OSPF Interaction
•
RFC 1745, BGP4/IDRP for IP—OSPF Interaction
•
RFC 1765, OSPF Database Overflow
•
RFC 1793, Extending OSPF to Support Demand Circuits
•
RFC 2154, OSPF with Digital Signatures
•
RFC 2328, OSPF Version 2
•
RFC 3101, OSPF Not-So-Stubby Area (NSSA) Option
•
RFC 3166, Request to Move RFC 1403 to Historic Status
•
RFC 3509, Alternative Implementations of OSPF Area Border Routers
•
RFC 4167, Graceful OSPF Restart Implementation Report
•
RFC 4577, OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private
Networks (VPNs)
•
RFC 4750, OSPF Version 2 Management Information Base
•
RFC 4811, OSPF Out-of-Band LSDB Resynchronization
•
RFC 4812, OSPF Restart Signaling
•
RFC 5088, OSPF Protocol Extensions for Path Computation Element (PCE) Discovery
•
RFC 5250, The OSPF Opaque LSA Option
•
RFC 5613, OSPF Link-Local Signaling
•
RFC 5642, Dynamic Hostname Exchange Mechanism for OSPF
•
RFC 5709, OSPFv2 HMAC-SHA Cryptographic Authentication
•
RFC 5786, Advertising a Router's Local Addresses in OSPF Traffic Engineering (TE)
Extensions
86
•
RFC 6571, Loop-Free Alternate (LFA) Applicability in Service Provider (SP) Networks
•
RFC 6860, Hiding Transit-Only Networks in OSPF
•
RFC 6987, OSPF Stub Router Advertisement
Restrictions and guidelines: OSPF configuration
Make a proper configuration plan to avoid incorrect settings that can result in route blocking and routing loops.
OSPF tasks at a glance
To configure OSPF, perform the following tasks:
1.
Configuring basic OSPF funtions
2.
(Optional.) Configuring OSPF areas
3.
(Optional.) Configuring OSPF network types
Configuring the broadcast network type for an interface
Configuring the NBMA network type for an interface
Configuring the P2MP network type for an interface
Configuring the P2P network type for an interface
4.
(Optional.) Configuring OSPF route control
Configuring OSPF inter-area route summarization
Configuring redistributed route summarization
Configuring received OSPF route filtering
Configuring Type-3 LSA filtering
Setting an OSPF cost for an interface
Setting the maximum number of ECMP routes
Configuring discard routes for summary networks
Redistributing routes from another routing protocol
Redistributing a default route
Advertising OSPF link state information to BGP
5.
(Optional.) Setting OSPF timers
Configuring OSPF packet timers
Setting LSA transmission delay
Setting SPF calculation interval
Setting the LSA arrival interval
Setting the LSA generation interval
87
Setting OSPF exit overflow interval
6.
(Optional.) Configuring OSPF packet parameters
Disabling interfaces from receiving and sending OSPF packets
Adding the interface MTU into DD packets
Setting the DSCP value for outgoing OSPF packets
Setting the maximum length of OSPF packets that can be sent by an interface
7.
(Optional.) Controlling LSA generation, advertisement, and reception
Setting the maximum number of external LSAs in LSDB
Filtering outbound LSAs on an interface
Filtering LSAs for the specified neighbor
Configuring update suppression
8.
(Optional.) Accelerating OSPF convergence speed
Configuring prefix suppression
Configuring prefix prioritization
9.
(Optional.) Configuring advanced OSPF features
Enabling compatibility with RFC 1583
Configuring OSPF dynamic host name mappings
10. (Optional.) Enhancing OSPF availability
11. (Optional.) Configuring OSPF security features
Configuring OSPF authentication
12.
(Optional.) Configuring GTSM for OSPF
13.
(Optional.) Configuring OSPF logging and SNMP notifications
Logging neighbor state changes
Configuring the OSPF logging feature
Configuring OSPF network management
Configuring basic OSPF funtions
Enabling an OSPF process
1. Enter system view. system-view
2. (Optional.) Configure a global router ID.
router id router-id
By default, no global router ID is configured.
88
If no global router ID is configured, the highest loopback interface IP address, if any, is used as the router ID. If no loopback interface IP address is available, the highest physical interface IP address is used, regardless of the interface status (up or down).
3. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
By default, OSPF is disabled.
4. (Optional.) Configure a description for the OSPF process.
description text
By default, no description is configured for the OSPF process.
As a best practice, configure a description for each OSPF process.
Configuring an OSPF area
1. Enter system view. system-view
2. (Optional.) Configure a global router ID.
router id router-id
By default, no global router ID is configured.
3. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
By default, OSPF is disabled.
4. (Optional.) Configure a description for the OSPF process. description text
By default, no description is configured for the OSPF process.
As a best practice, configure a description for each OSPF process.
5. Create an OSPF area, and enter OSPF area view. area area-id
6. (Optional.) Configure a description for the area. description text
By default, no description is configured for the area.
As a best practice, configure a description for each OSPF area.
7. (Optional.) Exclude interfaces in the OSPF area from the base topology. capability default-exclusion
By default, interfaces in an OSPF area belong to the base topology.
For correct neighbor relationship establishment, perform this task on both the local device and the neighbor device.
Enabling OSPF
About this task
To enable OSPF on a router, you must perform the following tasks:
1. Create an OSPF process.
2. Create an OSPF area for the process.
89
3. Specify a network in the area.
The interface attached to the network will run the OSPF process in the area. OSPF advertises the direct route of the interface.
OSPF supports multiple processes. To run multiple OSPF processes, you must specify an ID for each process. The process IDs take effect locally and has no influence on packet exchange between routers. Two routers with different process IDs can exchange packets.
OSPF supports multiple VPNs. You can configure an OSPF process to run in a VPN instance. An
OSPF process with no VPN instance specified runs on the public network. For more information about VPN, see MPLS Configuration Guide .
Restrictions and guidelines for enabling OSPF
When you configure OSPF on an interface, follow these restrictions and guidelines:
•
You can enable OSPF on the network where the interface resides or directly enable OSPF on that interface. If you configure both, the latter takes precedence.
•
If the specified OSPF process and area do not exist, the operation creates an OSPF process and area for the interface. Disabling an OSPF process on an interface does not delete the
OSPF process or the area.
Enabling OSPF on a network
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter OSPF area view. area area-id
4. Specify a network to enable the interface attached to the network to run the OSPF process in the area.
network ip-address wildcard-mask
By default, no network is specified.
A network can be added to only one area.
Enabling OSPF on an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable an OSPF process on the interface.
ospf process-id area area-id [ exclude-subip ]
By default, OSPF is disabled on an interface.
Configuring OSPF areas
About OSPF area configuration
This task allows you to configure an OSPF area as a stub area or NSSA area. It also allows you to create a virtual link if no connectivity can be achieved between a non-backbone area and backbone area, or in the backbone area.
90
Configuring a stub area
About this task
You can configure a non-backbone area at an AS edge as a stub area. To do so, execute the stub command on all routers attached to the area. The routing table size is reduced because Type-5 LSAs will not be flooded within the stub area. The ABR generates a default route into the stub area so all packets destined outside of the AS are sent through the default route.
To further reduce the routing table size and routing information exchanged in the stub area, configure a totally stub area by using the stub no-summary command on the ABR. AS external routes and inter-area routes will not be distributed into the area. All the packets destined for outside of the AS or area will be sent to the ABR for forwarding.
A stub or totally stub area cannot have an ASBR because external routes cannot be distributed into the area.
Restrictions and guidelines
Do not configure the backbone area as a stub area or totally stub area.
To configure an area as a stub area, execute the stub command on all routers attached to the area.
To configure an area as a totally stub area, execute the stub command on all routers attached to the area, and execute the stub no-summary command on the ABR.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter area view. area area-id
4. Configure the area as a stub area. stub [ default-route-advertise-always | no-summary ] *
By default, no stub area is configured.
5. (Optional.) Set a cost for the default route advertised to the stub area. default-cost cost-value
By default, the cost is 1 for the default route advertised to the stub area.
This command takes effect only on the ABR of a stub area or totally stub area.
Configuring an NSSA area
About this task
A stub area cannot import external routes, but an NSSA area can import external routes into the
OSPF routing domain while retaining other stub area characteristics.
To configure an area as a totally NSSA area, use the nssa no-summary command. The ABR of the area does not advertise inter-area routes into the area.
Restrictions and guidelines
Do not configure the backbone area as an NSSA area or totally NSSA area.
To configure an NSSA area, configure the nssa command on all the routers attached to the area.
91
To configure a totally NSSA area, configure the nssa command on all the routers attached to the area and configure the nssa no-summary command on the ABR.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter area view. area area-id
4. Configure the area as an NSSA area. nssa [ default-route-advertise [ cost cost-value | nssa-only |
route-policy route-policy-name | type type ] * | no-import-route | no-summary | suppress-fa | [ [ [ translate-always ]
[ translate-ignore-checking-backbone ] ] | translate-never ] |
translator-stability-interval value ] *
By default, no area is configured as an NSSA area.
5. (Optional.) Set a cost for the default route advertised to the NSSA area. default-cost cost-value
By default, the cost is 1 for the default route advertised to the NSSA area.
This command takes effect only on the ABR/ASBR on an NSSA area or totally NSSA area.
Configuring a virtual link
About this task
You can configure a virtual link to maintain connectivity between a non-backbone area and the backbone, or in the backbone itself.
Restrictions and guidelines
A virtual link cannot traverse a stub area, totally stub area, NSSA area, or totally NSSA area.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter OSPF area view. area area-id
4. Configure a virtual link. vlink-peer router-id [ dead seconds | hello seconds | { { hmac-md5 | hmac-sha-256 | md5 } key-id { cipher | plain } string | keychain keychain-name | simple { cipher | plain } string } | retransmit seconds
| trans-delay seconds ] *
Configure this command on both ends of a virtual link. The hello and dead intervals must be identical on both ends of the virtual link.
92
Configuring OSPF network types
Based on the link layer protocol, OSPF classifies networks into different types, including broadcast,
NBMA, P2MP, and P2P.
Restrictions and guidelines for configuring OSPF network types
If any routers in a broadcast network do not support multicasting, change the network type to NBMA.
If a router on an NBMA network has only one neighbor, you can change the network type to P2P to save costs.
Two broadcast-, NBMA-, and P2MP-interfaces can establish a neighbor relationship only when they are on the same network segment.
Configuring the broadcast network type for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the OSPF network type for the interface as broadcast. ospf network-type broadcast
By default, the network type of an interface depends on the link layer protocol.
When the link layer protocol is Ethernet or FDDI, OSPF classifies the network type as broadcast by default.
4. (Optional.) Set a router priority for the interface.
ospf dr-priority priority
The default router priority is 1.
Configuring the NBMA network type for an interface
Restrictions and guidelines
After you configure the network type as NBMA, you must specify neighbors and their router priorities because NBMA interfaces cannot find neighbors by broadcasting hello packets.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the OSPF network type for the interface as NBMA. ospf network-type nbma
By default, the network type of an interface is broadcast.
4. (Optional.) Set a router priority for the interface. ospf dr-priority priority
The default router priority for an interface is 1.
93
The router priority configured with this command is for DR election.
5. Return to system view. quit
6. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
7. Specify an NBMA neighbor. peer ip-address [ dr-priority priority ]
By default, no neighbor is specified.
The priority configured with this command indicates whether a neighbor has the election right or not. If you configure the router priority for a neighbor as 0, the local router determines the neighbor has no election right. It does not send hello packets to this neighbor. However, if the local router is the DR or BDR, it still sends hello packets to the neighbor for neighbor relationship establishment.
Configuring the P2MP network type for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the OSPF network type for the interface as P2MP. ospf network-type p2mp [ unicast ]
By default, the network type of an interface is broadcast.
After you configure the OSPF network type for an interface as P2MP unicast, all packets are unicast over the interface. The interface cannot broadcast hello packets to discover neighbors, so you must manually specify the neighbors.
4. Return to system view. quit
5. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
6. Specify a P2MP neighbor. peer ip-address [ cost cost-value ]
By default, no neighbor is specified
This step is required if the interface network type is P2MP unicast.
Configuring the P2P network type for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the OSPF network type for the interface as P2P. ospf network-type p2p [ peer-address-check ]
By default, the network type of an interface is broadcast.
94
Configuring OSPF route control
This section describes how to control the advertisement and reception of OSPF routing information, as well as route redistribution from other protocols.
Configuring OSPF inter-area route summarization
About this task
OSPF inter-area route summarization reduces the routing information exchanged between areas and the size of routing tables, and improves routing performance.
OSPF inter-area route summarization enables an ABR to summarize contiguous networks into a single network and advertise the network to other areas. For example, three internal networks
19.1.1.0/24, 19.1.2.0/24, and 19.1.3.0/24 are available within an area. You can configure the ABR to summarize the three networks into network 19.1.0.0/16, and advertise the summary network to other areas in a Type-3 LSA. This configuration reduces the scale of LSDBs on routers in other areas and the influence of topology changes.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter OSPF area view. area area-id
4. Configure ABR route summarization. abr-summary ip-address { mask-length | mask } [ advertise | not-advertise ] [ cost cost-value ]
By default, route summarization is not configured on an ABR.
Configuring redistributed route summarization
About this task
Perform this task to enable an ASBR to summarize external routes within the specified address range into a single route. The ASBR advertises only Type-5 LSAs to reduce the number of LSAs in the LSDB.
An ASBR can summarize routes in the following LSAs:
•
Type-5 LSAs.
•
Type-7 LSAs in an NSSA area.
Restrictions and guidelines
If an ASBR (also an ABR) is a translator in an NSSA area, it summarizes routes in Type-5 LSAs translated from Type-7 LSAs. If it is not a translator, it does not summarize routes in in Type-5 LSAs translated from Type-7 LSAs.
Procedure
1. Enter system view. system-view
2. Enter OSPF view.
95
ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure ASBR route summarization. asbr-summary ip-address { mask-length | mask } [ cost cost-value | not-advertise | nssa-only | tag tag ] *
By default, route summarization is not configured on an ASBR.
Configuring received OSPF route filtering
About this task
Perform this task to filter routes calculated using received LSAs.
The following filtering methods are available:
•
Use an ACL or IP prefix list to filter routing information by destination address.
•
Use the gateway prefix-list-name option to filter routing information by next hop.
•
Use an ACL or IP prefix list to filter routing information by destination address. At the same time use the gateway prefix-list-name option to filter routing information by next hop.
•
Use the route-policy route-policy-name option to filter routing information.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure OSPF to filter routes calculated using received LSAs. filter-policy { ipv4-acl-number [ gateway prefix-list-name ] | gateway prefix-list-name | prefix-list prefix-list-name [ gateway prefix-list-name ] | route-policy route-policy-name } import
By default, OSPF accepts all routes calculated by using received LSAs.
Configuring Type-3 LSA filtering
About this task
Perform this task to filter Type-3 LSAs advertised into the local area or other areas on an ABR.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter OSPF area view. area area-id
4. Configure Type-3 LSA filtering. filter { ipv4-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } { export | import }
By default, the ABR does not filter Type-3 LSAs.
96
Setting an OSPF cost for an interface
About this task
Set an OSPF cost for an interface by using either of the following methods:
•
Set the cost value in interface view.
•
Set a bandwidth reference value for the interface. OSPF computes the cost with this formula:
Interface OSPF cost = Bandwidth reference value (100 Mbps) / Expected interface bandwidth
(Mbps). The expected bandwidth of an interface is configured with the bandwidth command
(see Interface Command Reference ).
If the calculated cost is greater than 65535, the value of 65535 is used. If the calculated cost is less than 1, the value of 1 is used.
If no cost or bandwidth reference value is configured for an interface, OSPF computes the interface cost based on the interface bandwidth and default bandwidth reference value.
Setting an OSPF cost for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set an OSPF cost for the interface. ospf cost cost value
By default, the OSPF cost is calculated according to the interface bandwidth. For a loopback interface, the OSPF cost is 0 by default.
Setting a bandwidth reference value
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance instance-name ] *
3. Set a bandwidth reference value. bandwidth-reference value
The default setting is 100 Mbps.
Setting the maximum number of ECMP routes
About this task
OSPF might find multiple optimal equal-cost routes to the same destination, which can be used to share the traffic load. This task allows you to set the maximum number of ECMP routes for OSPF.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the maximum number of ECMP routes. maximum load-balancing number
97
By default, the maximum number of ECMP routes equals the maximum number of ECMP routes supported by the system.
Setting OSPF preference
About this task
A router can run multiple routing protocols, and each protocol is assigned a preference. If multiple routes are available to the same destination, the one with the highest protocol preference is selected as the best route.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set a preference for OSPF. preference [ ase ] { preference | route-policy route-policy-name } *
By default, the preference of OSPF internal routes is 10 and the preference of OSPF external routes is 150.
Configuring discard routes for summary networks
About this task
Perform this task on an ABR or ASBR to specify whether to generate discard routes for summary networks. You can also specify a preference for the discard routes.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure discard routes for summary networks. discard-route { external { preference | suppression } | internal
{ preference | suppression } } *
By default, the ABR or ASBR generates discard routes for summary networks and the default preference of discard routes is 255.
Redistributing routes from another routing protocol
About this task
On a router running OSPF and other routing protocols, you can configure OSPF to redistribute static routes, direct routes, or routes from other protocols, such as RIP, IS-IS, and BGP. OSPF advertises the routes in Type-5 LSAs or Type-7 LSAs. In addition, you can configure OSPF to filter redistributed routes so that OSPF advertises only permitted routes.
98
Restrictions and guidelines
OSPF redistributes only active routes. To view route status information, use the display ip routing-table protocol command.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure route redistribution. import-route bgp [ as-number ] [ allow-ibgp ] [ cost cost-value | nssa-only | route-policy route-policy-name | tag tag | type type ] * import-route { direct | static } [ cost cost-value | nssa-only |
route-policy route-policy-name | tag tag | type type ] * import-route { isis | ospf | rip } [ process-id | all-processes ]
[ allow-direct | cost cost-value | nssa-only | route-policy route-policy-name | tag tag | type type ] *
By default, OSPF does not redistribute routes.
The import-route bgp command redistributes only EBGP routes. The import-route bgp command with the allow-ibgp keyword specified redistributes both EBGP and IBGP routes, which might cause routing loops. When you use the allow-ibgp keyword, make sure you understand its impact on the network.
4. (Optional.) Configure OSPF to filter redistributed routes. filter-policy { ipv4-acl-number | prefix-list prefix-list-name } export [ bgp | direct | { isis | ospf | rip } [ process-id ] | static ]
By default, OSPF accepts all redistributed routes.
5. Configure the default parameters for redistributed routes (cost, tag, and type). default { cost cost-value | tag tag | type type } *
By default, the cost is 1, the tag is 1, and the route type is 2
Redistributing a default route
About this task
The import-route command cannot redistribute a default external route. Perform this task to redistribute a default route.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Redistribute a default route. default-route-advertise [ [ always | permit-calculate-other ] | cost cost-value | route-policy route-policy-name | type type ] * default-route-advertise [ summary cost cost-value ]
By default, no default route is redistributed.
99
This command is applicable only to VPNs. The PE router advertises a default route in a Type-3
LSA to a CE router.
4. Configure the default parameters for redistributed routes (cost, tag, and type). default { cost cost-value | tag tag | type type } *
By default, the cost is 1, the tag is 1, and the route type is 2
Advertising a host route
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter area view. area area-id
4. Advertise a host route. host-advertise ip-address cost-value
By default, OSPF does not advertise host routes that are not in the area.
Advertising OSPF link state information to BGP
About this task
After the device advertises OSPF link state information to BGP, BGP can advertise the information for intended applications. For more information about BGP LS, see "Configuring BGP LS."
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Advertise OSPF link state information to BGP. distribute bgp-ls [ instance-id id ] [ strict-link-checking ]
By default, the device does not advertise OSPF link state information to BGP.
Setting OSPF timers
About setting OSPF timers
This task allows you to change OSPF packet timers to adjust the convergence speed and network load and tune the delay time for sending LSAs on low-speed links.
Configuring OSPF packet timers
About this task
An OSPF interface includes the following timers:
100
•
Hello timer — Interval for sending hello packets. It must be identical on OSPF neighbors.
•
Poll timer — Interval for sending hello packets to a neighbor that is down on the NBMA network.
•
Dead timer — Interval within which if the interface does not receive any hello packet from the neighbor, it declares the neighbor is down.
•
LSA retransmission timer — Interval within which if the interface does not receive any acknowledgment packets after sending an LSA to the neighbor, it retransmits the LSA.
Restrictions and guidelines
The default value for the hello interval and neighbor dead interval depends on the network type.
When the network type for an interface is changed, the default hello interval and neighbor dead interval are restored. Make sure two neighboring interfaces are configured with the same hello interval and neighbor dead interval. Inconsistent settings will affect the OSPF neighbor relationship establishment.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the hello interval. ospf timer hello seconds
The default hello interval on P2P and broadcast interfaces is 10 seconds. The default hello interval on P2MP and NBMA interfaces is 30 seconds.
4. Set the poll interval. ospf timer poll seconds
The default setting is 120 seconds.
The poll interval is a minimum of four times the hello interval.
5. Set the dead interval. ospf timer dead seconds
The default dead interval on P2P and broadcast interfaces is 40 seconds. The default dead interval on P2MP and NBMA interfaces is 120 seconds.
The dead interval must be a minimum of four times the hello interval on an interface.
6. Set the retransmission interval. ospf timer retransmit interval
The default retransmission interval is 5 seconds.
A retransmission interval setting that is too small can cause unnecessary LSA retransmissions.
Typically set a bigger interval than the round-trip time of a packet between two neighbors.
Setting LSA transmission delay
About this task
To avoid LSAs from aging out during transmission, set an LSA retransmission delay especially for low speed links.
Procedure
1. Enter system view. system-view
2. Enter interface view.
101
interface interface-type interface-number
3. Set the LSA transmission delay. ospf trans-delay seconds
The default LSA transmission delay is 1 second.
Setting SPF calculation interval
About this task
LSDB changes result in SPF calculations. When the topology changes frequently, a large amount of network and router resources are occupied by SPF calculation. You can adjust the SPF calculation interval to reduce the impact.
For a stable network, the minimum interval is used. If network changes become frequent, the SPF calculation interval increases by the incremental interval × 2 n-2
for each calculation until the maximum interval is reached. The value n is the number of calculation times.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the SPF calculation interval. spf-schedule-interval { maximum-interval [ minimum-interval
[ incremental-interval [ conservative ] ] ] | millisecond interval }
By default, the maximum interval is 5 seconds, the minimum interval is 50 milliseconds, and the incremental interval is 200 milliseconds.
Setting the LSA arrival interval
About this task
For a stable network, LSAs arrive at the minimum interval. If network changes become frequent, the
LSA arrival interval increases by the incremental interval × 2 n-2
for each arrival until the maximum interval is reached. The value n is the number of arrival times.
OSPF drops any duplicate LSAs within the LSA arrival interval. An LSA is a duplicate of a previous
LSA if they have the same LSA type, LS ID, and router ID.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the LSA arrival interval. lsa-arrival-interval maximum-interval [ minimum-interval
[ incremental-interval ] ]
By default, the maximum interval is 1000 milliseconds, the minimum interval is 500 milliseconds, and the incremental interval is 500 milliseconds.
102
Setting the LSA generation interval
About this task
Adjust the LSA generation interval to protect network resources and routers from being overwhelmed by LSAs at the time of frequent network changes.
For a stable network, the minimum interval is used. If network changes become frequent, the LSA generation interval increases by the incremental interval × 2 n-2
for each generation until the maximum interval is reached. The value n is the number of generation times.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the LSA generation interval. lsa-generation-interval maximum-interval [ minimum-interval
[ incremental-interval ] ]
By default, the maximum interval is 5 seconds, the minimum interval is 50 milliseconds, and the incremental interval is 200 milliseconds.
Setting OSPF exit overflow interval
About this task
When the number of LSAs in the LSDB exceeds the upper limit, the LSDB is in an overflow state. In this state, OSPF does not receive any external LSAs and deletes the external LSAs generated by itself to save system resources.
This task allows you to configure the interval that OSPF exits overflow state.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the interval that OSPF exits overflow state.
lsdb-overflow-interval interval
By default, the OSPF exit overflow interval is 300 seconds. An interval of 0 means that OSPF does not exit overflow state.
Setting the LSU transmit rate
About this task
During LSDB synchronization, if the local router has multiple neighbors, it must send many LSUs to each neighbor. When a neighbor receives excessive LSUs within a short time period, the following events might occur:
•
The neighbor experiences degraded performance because it uses too many system resources to process the received LSU packets.
103
•
The neighbor drops hello packets used for maintaining the neighbor relationship because it is busy dealing with the LSUs. As a result, the neighbor relationship is torn down. To reestablish a relationship to the neighbor, the local router must send more LSUs to the neighbor. This exacerbates the performance degradation.
This task allows you to limit the LSU transmit rate by setting the LSU transmit interval and the maximum number of LSUs that can be sent at each interval.
Procedure
1. Enter system view. system-view
2. Enable OSPF to limit the LSU transmit rate.
ospf lsu-flood-control [ interval count ]
By default, OSPF does not limit the LSU transmit rate.
Inappropriate use of this command might cause abnormal routing. As a best practice, execute this command with the default values.
3. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
4. (Optional.) Set the LSU transmit rate. transmit-pacing interval interval count count
By default, an OSPF interface sends a maximum of three LSU packets every 20 milliseconds.
Configuring OSPF packet parameters
Disabling interfaces from receiving and sending OSPF packets
About this task
To enhance OSPF adaptability and reduce resource consumption, you can set an OSPF interface to
"silent." A silent OSPF interface blocks OSPF packets and cannot establish any OSPF neighbor relationship. However, other interfaces on the router can still advertise direct routes of the interface in
Router LSAs.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Disable interfaces from receiving and sending OSPF packets. silent-interface { interface-type interface-number | all }
By default, an OSPF interface can receive and send OSPF packets.
This command disables only the interfaces associated with the current process rather than other processes. Multiple OSPF processes can disable the same interface from receiving and sending OSPF packets.
104
Adding the interface MTU into DD packets
About this task
By default, an OSPF interface adds a value of 0 into the interface MTU field of a DD packet rather than the actual interface MTU. You can enable an interface to add its MTU into DD packets.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable the interface to add its MTU into DD packets. ospf mtu-enable
By default, the interface adds an MTU value of 0 into DD packets.
Setting the DSCP value for outgoing OSPF packets
About this task
The DSCP value specifies the precedence of outgoing packets.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the DSCP value for outgoing OSPF packets. dscp dscp-value
By default, the DSCP value for outgoing OSPF packets is 48.
Setting the maximum length of OSPF packets that can be sent by an interface
About this task
Perform this task to set the packet size limit on an interface. In some scenarios, for example, when you establish OSPF neighbors over a tunnel, you can perform this task to prevent OSPF packet fragmentation on the outgoing tunnel interface. Make sure the maximum length of the OSPF packets plus the encapsulated header length is no greater than the outgoing tunnel interface's MTU. For more information about tunnel interfaces, see tunnel interface configuration in Interface
Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the maximum length of OSPF packets that can be sent by an interface.
105
ospf packet-size value
By default, the maximum length of OSPF packets that an interface can send equals the interface's MTU.
Controlling LSA generation, advertisement, and reception
Setting the maximum number of external LSAs in LSDB
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the maximum number of external LSAs in the LSDB. lsdb-overflow-limit number
By default, the maximum number of external LSAs in the LSDB is not limited.
Filtering outbound LSAs on an interface
About this task
To reduce the LSDB size for the neighbor and save bandwidth, you can perform this task on an interface to filter LSAs to be sent to the neighbor.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Filter outbound LSAs on the interface. ospf database-filter { all | { ase [ acl ipv4-acl-number ] | nssa [ acl ipv4-acl-number ] | summary [ acl ipv4-acl-number ] } * }
By default, the outbound LSAs are not filtered on the interface.
Filtering LSAs for the specified neighbor
About this task
On a P2MP network, a router might have multiple P2MP type OSPF neighbors. Perform this task to prevent the router from sending LSAs to the specified P2MP neighbor.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
106
3. Filter LSAs for the specified P2MP neighbor.
database-filter peer ip-address { all | { ase [ acl ipv4-acl-number ] | nssa [ acl ipv4-acl-number ] | summary [ acl ipv4-acl-number ] } * }
By default, the LSAs for the specified P2MP neighbor are not filtered.
Configuring update suppression
About this task
When route flaps occur on an OSPF network, the devices consecutively flood LSAs into the network.
This might cause more route flaps. Moreover, excessive LSAs can cause frequent route calculation, which costs too much CPU resources and degrades the performance of the devices. To prevent this problem, you can perform this task to suppress routing update during route flapping.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Suppress the generation of LSAs during route flapping.
lsa-generation-interval suppress-flapping delay-interval
[ threshold threshold-value ]
By default, the LSA generation is not suppressed during route flapping.
4. Suppress incoming LSAs during route flapping.
lsa-arrival-interval suppress-flapping delay-interval [ threshold threshold-value ]
By default, incoming LSAs are not suppressed during route flapping.
5. Set the delay for route calculation triggered by router LSAs with max age.
maxage-lsa route-calculate-delay delay-interval
By default, the delay is 10 seconds for route calculation triggered by router LSAs with max age.
Accelerating OSPF convergence speed
Enabling OSPF ISPF
About this task
When the topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable OSPF ISPF. ispf enable
107
By default, OSPF ISPF is enabled.
Configuring prefix suppression
About this task
By default, an OSPF interface advertises all of its prefixes in LSAs. To speed up OSPF convergence, you can suppress interfaces from advertising all of their prefixes. This feature helps improve network security by preventing IP routing to the suppressed networks.
When prefix suppression is enabled:
•
On P2P and P2MP networks, OSPF does not advertise Type-3 links in Type-1 LSAs. Other routing information can still be advertised to ensure traffic forwarding.
•
On broadcast and NBMA networks, the DR generates Type-2 LSAs with a mask length of 32 to suppress network routes. Other routing information can still be advertised to ensure traffic forwarding. If no neighbors exist, the DR does not advertise Type-3 links in Type-1 LSAs.
Restrictions and guidelines for prefix suppression
As a best practice, configure prefix suppression on all OSPF routers if you want to use prefix suppression.
Configuring prefix suppression for an OSPF process
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable prefix suppression for the OSPF process. prefix-suppression
By default, prefix suppression is disabled for an OSPF process.
This feature does not suppress the prefixes of secondary IP addresses, loopback interfaces, and passive interfaces.
Configuring prefix suppression for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable prefix suppression for the interface. ospf prefix-suppression [ disable ]
By default, prefix suppression is disabled on an interface.
This feature does not suppress prefixes of secondary IP addresses.
Configuring prefix prioritization
About this task
This feature enables the device to install prefixes in descending priority order: critical, high, medium, and low. The prefix priorities are assigned through routing policies. When a route is assigned multiple prefix priorities, the route uses the highest priority.
By default, the 32-bit OSPF host routes have a medium priority and other routes have a low priority.
108
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable prefix prioritization.
prefix-priority route-policy route-policy-name
By default, prefix prioritization is disabled.
Configuring OSPF PIC
About this task
Prefix Independent Convergence (PIC) enables the device to speed up network convergence by ignoring the number of prefixes.
Restrictions and guidelines for OSPF PIC
When both OSPF PIC and OSPF FRR are configured, OSPF FRR takes effect.
OSPF PIC applies only to inter-area routes and external routes.
Enabling OSPF PIC
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable PIC for OSPF. pic [ additional-path-always ]
By default, OSPF PIC is enabled.
Configuring BFD control packet mode for OSPF PIC
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for OSPF PIC. ospf primary-path-detect bfd ctrl
By default, BFD control packet mode is disabled for OSPF PIC.
This mode requires BFD configuration on both OSPF routers on the link.
Configuring BFD echo packet mode for OSPF PIC
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets. bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
109
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for OSPF PIC. ospf primary-path-detect bfd echo
By default, BFD echo packet mode is disabled for OSPF PIC.
This mode requires BFD configuration on one OSPF router on the link.
Configuring advanced OSPF features
Configuring stub routers
About this task
A stub router is used for traffic control. It reports its status as a stub router to neighboring OSPF routers. The neighboring routers can have a route to the stub router, but they do not use the stub router to forward data.
Router LSAs from the stub router might contain different link type values. A value of 3 means a link to a stub network, and the cost of the link will not be changed by default. To set the cost of the link to
65535, specify the include-stub keyword in the stub-router command. A value of 1, 2 or 4 means a point-to-point link, a link to a transit network, or a virtual link. On such links, a maximum cost value of 65535 is used. Neighbors do not send packets to the stub router as long as they have a route with a smaller cost.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure the router as a stub router. stub-router [ external-lsa [ max-metric-value ] | include-stub | on-startup { seconds | wait-for-bgp [ seconds ] } | summary-lsa
[ max-metric-value ] ] *
By default, the router is not configured as a stub router.
A stub router is not related to a stub area.
Enabling compatibility with RFC 1583
About this task
RFC 1583 specifies a different method than RFC 2328 for selecting the optimal route to a destination in another AS. When multiple routes are available to the ASBR, OSPF selects the optimal route by using the following procedure:
1. Selects the route with the highest preference.
If RFC 2328 is compatible with RFC 1583, all these routes have equal preference.
110
If RFC 2328 is not compatible with RFC 1583, the intra-area route in a non-backbone area is preferred to reduce the burden of the backbone area. The inter-area route and intra-area route in the backbone area have equal preference.
2. Selects the route with the lower cost if two routes have equal preference.
3. Selects the route with the larger originating area ID if two routes have equal cost.
Restrictions and guidelines
To avoid routing loops, set identical RFC 1583-compatibility on all routers in a routing domain.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable compatibility with RFC 1583. rfc1583 compatible
By default, compatibility with RFC 1583 is enabled.
Configuring OSPF dynamic host name mappings
About this task
OSPF uses a router ID to uniquely identify a router in an AS. The length of router IDs is fixed at 4 bytes. It is inconvenient for the network administrator to memorize the router IDs in dotted decimal notation when verifying the OSPF neighbor relationships, routing tables, and LSDBs.
This task allows you to map a router ID to a host name. The mapping table is maintained by OSPF routers. Host names are more straightforward than router IDs in network maintenance, management, and failure diagnosis.
Restrictions and guidelines
OSPF uses Type-10 LSAs and Type-11 LSAs to carry information about the dynamic host name attribute. Therefore, make sure the opaque LSA reception and advertisement capability is enabled.
Procedure
1. Enter system view. system-view
2. Enable OSPF, and enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable the opaque LSA reception and advertisement capability. opaque-capability enable
By default, the opaque LSA reception and advertisement capability is enabled.
4. Enable the OSPF dynamic host name mapping feature. hostname [ host-name ]
By default, the OSPF dynamic host name mapping feature is disabled.
111
Configuring OSPF GR
About OSPF GR
GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.
Two routers are required to complete a GR process. The following are router roles in a GR process:
•
GR restarter —Graceful restarting router. It must have GR capability.
•
GR helper —A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
OSPF GR has the following types:
•
IETF GR —Uses Opaque LSAs to implement GR.
•
Non-IETF GR —Uses link local signaling (LLS) to advertise GR capability and uses out of band synchronization to synchronize the LSDB.
A device can act as a GR restarter and GR helper at the same time.
Restrictions and guidelines for OSPF GR
You cannot enable OSPF NSR on a device that acts as GR restarter.
Configuring OSPF GR restarter
Configuring the IETF OSPF GR restarter
1. Enter system view. system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable opaque LSA reception and advertisement capability. opaque-capability enable
By default, opaque LSA reception and advertisement capability is enabled.
4. Enable the IETF GR. graceful-restart ietf [ global | planned-only ] *
By default, the IETF GR capability is disabled.
5. (Optional.) Set the GR interval. graceful-restart interval interval
By default, the GR interval is 120 seconds.
Configuring the non-IETF OSPF GR restarter
1. Enter system view. system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable the link-local signaling capability.
112
enable link-local-signaling
By default, the link-local signaling capability is disabled.
4. Enable the out-of-band re-synchronization capability. enable out-of-band-resynchronization
By default, the out-of-band re-synchronization capability is disabled.
5. Enable non-IETF GR. graceful-restart [ nonstandard ] [ global | planned-only ] *
By default, non-IETF GR capability is disabled.
6. (Optional.) Set the GR interval. graceful-restart interval interval
By default, the GR interval is 120 seconds.
Configuring OSPF GR helper
Configuring the IETF OSPF GR helper
1. Enter system view. system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable opaque LSA reception and advertisement capability. opaque capability enable
By default, opaque LSA reception and advertisement capability is enabled.
4. Enable GR helper capability. graceful-restart helper enable [ planned-only ]
By default, GR helper capability is enabled.
5. (Optional.) Enable strict LSA checking for the GR helper. graceful-restart helper strict-lsa-checking
By default, strict LSA checking for the GR helper is disabled.
When an LSA change on the GR helper is detected, the GR helper device exits the GR helper mode.
Configuring the non-IETF OSPF GR helper
1. Enter system view. system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable the link-local signaling capability. enable link-local-signaling
By default, the link-local signaling capability is disabled.
4. Enable the out-of-band re-synchronization capability. enable out-of-band-resynchronization
By default, the out-of-band re-synchronization capability is disabled.
5. Enable GR helper.
113
graceful-restart helper enable
By default, GR helper is enabled.
6. (Optional.) Enable strict LSA checking for the GR helper. graceful-restart helper strict-lsa-checking
By default, strict LSA checking for the GR helper is disabled.
When an LSA change on the GR helper is detected, the GR helper device exits the GR helper mode.
Triggering OSPF GR
About this task
You can trigger OSPF GR by performing an active/standby switchover or using the reset ospf process command.
Procedure
To trigger OSPF GR, execute the reset ospf [ process id ] process graceful-restart command in user view.
Configuring OSPF NSR
About this task
Nonstop routing (NSR) backs up OSPF link state information from the active process to the standby process. After an active/standby switchover, NSR can complete link state recovery and route regeneration without tearing down adjacencies or impacting forwarding services.
NSR does not require the cooperation of neighboring devices to recover routing information, and it is typically used more often than GR.
Restrictions and guidelines
A device that has OSPF NSR enabled cannot act as GR restarter.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable OSPF NSR. non-stop-routing
By default, OSPF NSR is disabled.
This command takes effect only for the current process. As a best practice, enable OSPF NSR for each process if multiple OSPF processes exist.
114
Configuring BFD for OSPF
About BFD for OSPF
BFD provides a single mechanism to quickly detect and monitor the connectivity of links between
OSPF neighbors, which improves the network convergence speed. For more information about BFD, see High Availability Configuration Guide .
OSPF supports the following BFD detection modes:
•
Bidirectional control detection —Requires BFD configuration to be made on both OSPF routers on the link.
•
Single-hop echo detection —Requires BFD configuration to be made on one OSPF router on the link.
Configuring bidirectional control detection
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD bidirectional control detection. ospf bfd enable
By default, BFD bidirectional control detection is disabled.
Both ends of a BFD session must be on the same network segment and in the same area.
Configuring single-hop echo detection
1. Enter system view. system-view
2. Configure the source address of echo packets. bfd echo-source-ip ip-address
By default, the source address of echo packets is not configured.
The source IP address cannot be on the same network segment as any local interfaces.
For more information about this command, see BFD commands in High Availability Command
Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD single-hop echo detection. ospf bfd enable echo
By default, BFD single-hop echo detection is disabled.
115
Configuring OSPF FRR
About OSPF FRR
OSPF Fast Reroute (FRR) calculates a backup path based on the LSDB or specifies a backup path by using a routing policy. Then, it saves the backup path information to the FIB. When the primary path fails, the system immediately switches traffic to the backup path to prevent traffic loss and reduce the route convergence time.
OSPF supports Loop Free Alternate (LFA) FRR and remote LFA FRR.
The following OSPF FRR traffic protection types are available:
•
Link protection —Protects traffic that traverses a specific link.
•
Node protection —Protects traffic that traverses a specific node.
Node protection takes precedence over link protection.
Restrictions and guidelines for OSPF FRR
If both OSPF FRR and PIC are configured, OSPF FRR takes effect.
OSPF FRR tasks at a glance
To configure OSPF FRR, perform the following tasks:
1. Configuring an OSPF backup path
Perform a minimum of one task.
Configuring OSPF remote LFA FRR
Configuring OSPF FRR to use a backup next hop specified in a routing policy
2.
(Optional.) Setting the priority for FRR backup path selection policies
3. (Optional.) Configuring BFD for OSPF FRR
Configuring BFD control packet mode for OSPF FRR
Configuring BFD echo packet mode for OSPF FRR
Configuring OSPF LFA FRR
About this task
A link or router failure on a path can cause packet loss until OSPF completes routing convergence based on the new network topology. FRR enables fast rerouting to minimize the impact of link or node failures.
Figure 24 Network diagram for OSPF FRR
Backup nexthop: Router C
Router A Router B
116
Nexthop: Router D Router E
As shown in Figure 24 , configure OSPF FRR on Router B to calculate a backup next hop by using
the LFA algorithm. When the primary link fails, OSPF directs packets to the backup next hop. At the same time, OSPF calculates the shortest path based on the new network topology. It forwards packets over the path after network convergence.
Restrictions and guidelines for OSPF FRR
Do not use the fast-reroute lfa command together with the vlink-peer command.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Enable LFA on an interface. ospf fast-reroute lfa-backup
By default, the interface is enabled with LFA and it can be selected as a backup interface.
4. Return to system view. quit
5. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
6. Enable OSPF FRR to use the LFA algorithm to calculate a backup next hop. fast-reroute lfa [ abr-only ]
By default, OSPF FRR is disabled.
If abr-only is specified, the route to the ABR is selected as the backup path.
Configuring OSPF remote LFA FRR
About this task
In a network topology where OSPF LFA FRR cannot calculate the backup path, configure remote
LFA FRR to ensure network reliability.
Remote LFA uses the following concepts:
•
P space —Use the source node of the protected link as the root to establish a shortest path tree.
All nodes that are reachable from the source node without passing the protected link form the P space. Nodes in the P space are called P nodes.
•
Extended P space —Use the source node of the protected link and its neighbors as the roots to establish shortest path trees. All nodes that are reachable from the source node or one of its neighbors without passing the protected link form the extended P space. The P space is a subset of the extended P space.
•
Q space —Use the destination node of the protected link as the root to establish a reverse shortest path tree. All nodes that are reachable from the root node without passing the protected link form the Q space. Nodes in the Q space are called Q nodes.
•
PQ node —A PQ node refers to a node that resides in both the extended P space and the Q space. Remote LFA uses a PQ node as the destination node of a protected link.
As shown in Figure 25 , the traffic forwarding path is PE 1—P 1—P 2—PE 2. To avoid traffic loss
caused by link failures between P 1 and P 2, the system establishes an LDP tunnel between P 1 and
P 4, which is the PQ node. When the link between P 1 and P 2 fails, P 1 encapsulates IP packets in
MPLS packets and sends the MPLS packets to P 4 through the LDP tunnel. After receiving the
117
MPLS packets, P 4 removes the MPLS labels of the packets and then forwards the packets to the next hop based on the IP routing table.
The system determines P 4 as the PQ node as follows:
1. Uses P 1 (source node of the protected link) and its neighbors except P 2 (which passes the protected link) as the roots to establish shortest path trees.
2. Finds out all nodes that are reachable from P 1 or one of its neighbors without passing the protected link, which are PE 1, P 1, P 3, and P 4.
These nodes form the extended P space.
3. Uses P 2 (destination node of the protected link) as the root to establish a reverse shortest path tree.
4. Finds out all nodes that are reachable from P 2 without passing the protected link, which are PE
2 and P 4.
These nodes form the Q space.
5. Finds out all nodes that reside in both the extended P space and the Q space.
Only P 4 resides in both the extended P space and the Q space, so P 4 is the PQ node of the protected link.
Figure 25 Network diagram for OSPF remote LFA FRR
PE 1 P 1 P 2 PE 2
5 5 5
LSP
10 10
Q space
Extended P space
10
P 3 P 4
PQ node
Prerequisites
Enable MPLS and MPLS LDP on all nodes and interfaces participating in MPLS forwarding. For more information, see basic MPLS configuration and LDP configuration in MPLS Configuration
Guide .
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable OSPF remote LFA FRR. fast-reroute remote-lfa tunnel ldp
By default, OSPF remote LFA FRR is disabled.
4. (Optional.) Set the maximum cost from the source node of a protected link to a PQ node.
fast-reroute remote-lfa maximum-cost cost
By default, the maximum cost from the source node of a protected link to a PQ node is
16777215.
5. (Optional.) Specify a prefix list to filter PQ nodes.
118
fast-reroute remote-lfa prefix-list prefix-list-name
By default, no prefix list is specified to filter PQ nodes. Any PQ node can be selected as the backup next hop.
Multiple PQ nodes might reach the source node of a specific protected link. You can use this command to specify a prefix list to filter PQ nodes.
6. (Optional.) Disable remote LFA calculation on an interface. a. Return to system view. quit b. Enter interface view. interface interface-type interface-number c. Disable remote LFA calculation on the interface. ospf fast-reroute remote-lfa disable
By default, remote LFA calculation is enabled on the interface.
Configuring OSPF FRR to use a backup next hop specified in a routing policy
About this task
Before you perform this task, use the apply fast-reroute backup-interface command to specify a backup next hop in a routing policy for OSPF FRR. For more information about the apply fast-reroute backup-interface command and routing policy configuration, see
" Configuring routing policies ."
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable OSPF FRR to use a backup next hop specified in a routing policy. fast-reroute route-policy route-policy-name
By default, OSPF FRR is disabled.
Setting the priority for FRR backup path selection policies
About this task
By default, OSPF uses the node-protection policy to select the backup path. As shown in Figure 26 ,
traffic forwarding path Device A->Device D->Device E->Device F has two backup paths: Device
A->Device C->Device E->Device F and Device A->Device B->Device E->Device F . Because
Device C has higher forwarding capability than Device B, OSPF prefers backup path Device
A->Device C->Device E->Device F .
119
Figure 26 Node-protection backup path selection
Device C
10
10
20
10 10
Device A
Device D Device E Device F
10 15
Device B
To apply the lowest-cost policy that is more applicable in certain networks, perform this task to set a
Device A->Device D->Device E has two backup paths: Device A->Device C->Device D->Device
E and Device A->Device B->Device D->Device E . By default, OSPF selects backup path Device
A->Device C->Device D->Device E according to the node-protection policy. For OSPF to select backup path Device A->Device B->Device D->Device E , set a higher priority for the lowest-cost policy than the node-protection policy.
Figure 27 Lowest-cost backup path selection
Device C
10 20
10 10
Device A
10 15
Device D Device E
Device B
As shown in Figure 28 , traffic from Device S to Device E is shared between Link 1 and Link 2, which
share the same resource and have the same failure risk. To avoid backup path failure, add Link 1 and
Link 2 to the same Shared Risk Link Group (SRLG) and configure OSPF to use the SRLG-disjoint backup path selection policy. Then, Devise S will take Link 3 as the backup path. For more information about SRLGs, see MPLS TE configuration in MPLS Configuration Guide .
120
Figure 28 SRLG-disjoint backup path selection
Device S Device E
Link 1
Cost 10
Link 2 Cost 10
Link 3
Cost 10
Cost 10
Device N
Restrictions and guidelines
Cost 10
Device D
When you configure multiple backup path selection policies for an OSPF process, OSPF first uses the policy with the highest priority to calculate a backup path. If the backup path calculation fails,
OSPF works as follows:
•
If the SRLG-disjoint policy has the highest priority but the backup path calculation fails, OSPF selects the one with the higher priority from the node-protection and lowest-cost policies:
If the node-protection policy has the higher priority but the backup path calculation still fails,
OSPF uses the lowest-cost policy for further calculation.
If the lowest-cost policy has the higher priority but the backup path calculation still fails,
OSPF does not perform further backup path calculation.
•
If the node-protection policy has the highest priority but the backup path calculation fails, OSPF selects the one with the higher priority from the SRLG-disjoint and lowest-cost policies:
If the SRLG-disjoint policy has the higher priority but the backup path calculation still fails,
OSPF uses the lowest-cost policy for further calculation.
If the lowest-cost policy has the higher priority but the backup path calculation still fails,
OSPF does not perform further backup path calculation.
•
If the lowest-cost policy has the highest priority but the backup path calculation fails, OSPF does not perform further backup path calculation.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Set the priority for the node-protection, lowest-cost, or SRLG-disjoint backup path selection policy. fast-reroute tiebreaker { lowest-cost | node-protecting | srlg-disjoint } preference preference
By default, the priority values of the node-protection, lowest-cost, and SRLG-disjoint backup path selection policies are 40, 20, and 10, respectively.
121
Configuring BFD control packet mode for OSPF FRR
About this task
By default, OSPF FRR does not use BFD to detect primary link failures. To speed up OSPF convergence, enable BFD control packet mode for OSPF FRR to detect primary link failures. This mode requires BFD configuration on both OSPF routers on the link.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for OSPF FRR. ospf primary-path-detect bfd ctrl
By default, BFD control packet mode is disabled for OSPF FRR.
Configuring BFD echo packet mode for OSPF FRR
About this task
By default, OSPF FRR does not use BFD to detect primary link failures. To speed up OSPF convergence, enable BFD echo packet mode for OSPF FRR to detect primary link failures. This mode requires BFD configuration on one OSPF router on the link.
Procedure
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets. bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for OSPF FRR. ospf primary-path-detect bfd echo
By default, BFD echo packet mode is disabled for OSPF FRR.
Configuring OSPF authentication
About OSPF area and interface authentication
Perform this task to configure OSPF area and interface authentication.
OSPF adds the configured key into sent packets, and uses the key to authenticate received packets.
Only packets that pass the authentication can be received. If a packet fails the authentication, the
OSPF neighbor relationship cannot be established.
122
If you configure OSPF authentication for both an area and an interface in that area, the interface uses the OSPF authentication configured on it.
Configuring OSPF area authentication
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter area view. area area-id
4. Configure area authentication mode.
Configure MD5/HMAC-MD5/HMAC-SHA-256 authentication.
authentication-mode { hmac-md5 | hmac-sha-256 | md5 } key-id { cipher
| plain } string
Configure simple authentication.
authentication-mode simple { cipher | plain } string
Configure keychain authentication.
authentication-mode keychain keychain-name
For information about keychains, see Security Configuration Guide .
By default, no authentication is configured.
You must configure the same authentication mode and key on all the routers in an area.
Configuring OSPF interface authentication
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure interface authentication mode.
Configure simple authentication.
ospf authentication-mode simple { cipher | plain } string
Configure MD5/HMAC-MD5/HMAC-SHA-256 authentication.
ospf authentication-mode { hmac-md5 | hmac-sha-256 | md5 } key-id
{ cipher | plain } string
Configure keychain authentication.
ospf authentication-mode keychain keychain-name
For information about keychains, see Security Configuration Guide .
By default, no authentication is configured.
You must configure the same authentication mode and key on both the local interface and its peer interface.
123
Configuring GTSM for OSPF
About GTSM
The Generalized TTL Security Mechanism (GTSM) protects the device by comparing the TTL value in the IP header of incoming OSPF packets against a valid TTL range. If the TTL value is within the valid TTL range, the packet is accepted. If not, the packet is discarded.
The valid TTL range is from 255 – the configured hop count + 1 to 255.
When GTSM is configured, the OSPF packets sent by the device have a TTL of 255.
Restrictions and guidelines for GTSM
To use GTSM, you must configure GTSM on both the local and peer devices. You can specify different hop-count values for them.
The GTSM configuration in OSPF area view applies to all OSPF interfaces in the area. The GTSM configuration in interface view takes precedence over the configuration in OSPF area view.
GTSM checks OSPF packets from common neighbors and virtual link neighbors. It does not check
OSPF packets from sham link neighbors. For information about GTSM for OSPF sham links, see
MPLS Configuration Guide .
Configuring GTSM in OSPF area view
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enter OSPF area view. area area-id
4. Enable GTSM for the OSPF area. ttl-security [ hops hop-count ]
By default, GTSM is disabled for the OSPF area.
Configuring GTSM in interface view
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure GTSM for the interface.
Enable GTSM for the interface. ospf ttl-security [ hops hop-count ]
Disable GTSM for the interface. ospf ttl-security disable
Disable GTSM for an interface when the following conditions exist:
124
−
The area to which the interface belongs is enabled with GTSM.
−
The neighbor of the interface does not support GTSM.
By default, an interface uses the GTSM configuration of the area to which the interface belongs.
Configuring OSPF logging and SNMP notifications
Logging neighbor state changes
About this task
Perform this task to enable output of neighbor state change logs to the information center. The information center processes the logs according to user-defined output rules (whether and where to output logs). For more information about the information center, see information center configuration in System Management Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Enable the logging of neighbor state changes. log-peer-change
By default, this feature of logging neighbor state changes is enabled.
Configuring the OSPF logging feature
About this task
OSPF logs include LSA aging logs, route calculation logs, neighbor logs, OSPF route logs, and self-originated and received LSA logs.
Procedure
1. Enter system view. system-view
2. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
3. Configure the OSPF logging feature. event-log { hello { received [ abnormal | dropped ] | sent [ abnormal | failed ] } | lsa-flush | peer | route | spf } size count event-log lsa-history { asbr | ase | include-duplicate | link-state-id
| network | nssa | opaque-area | opaque-as | opaque-link | originate-router advertising-router-id | router | size count | summary
| verbose } *
By default, the device can generate a maximum of 100 OSPF logs for each type.
125
Configuring OSPF network management
About this task
This task involves the following configurations:
•
Bind an OSPF process to MIB so that you can use network management software to manage the specified OSPF process.
•
Enable SNMP notifications for OSPF to report important events.
•
Configure the SNMP notification output interval and the maximum number of SNMP notifications that can be output at each interval.
To report critical OSPF events to an NMS, enable SNMP notifications for OSPF. For SNMP notifications to be sent correctly, you must also configure SNMP on the device. For more information about SNMP configuration, see the network management and monitoring configuration guide for the device.
Procedure
1. Enter system view. system-view
2. Bind MIB to an OSPF process.
ospf mib-binding process-id
By default, MIB is bound to the process with the smallest process ID.
3. Enable SNMP notifications for OSPF. snmp-agent trap enable ospf [ authentication-failure | bad-packet | config-error | grhelper-status-change | grrestarter-status-change | if-state-change | lsa-maxage | lsa-originate | lsdb-approaching-overflow | lsdb-overflow | neighbor-state-change | nssatranslator-status-change | retransmit | virt-authentication-failure | virt-bad-packet | virt-config-error | virt-retransmit | virtgrhelper-status-change | virtif-state-change | virtneighbor-state-change ] *
By default, SNMP notifications for OSPF are enabled.
4. Enter OSPF view. ospf [ process-id | router-id { auto-select | router-id } | vpn-instance vpn-instance-name ] *
5. Configure the SNMP notification output interval and the maximum number of SNMP notifications that can be output at each interval.
snmp trap rate-limit interval trap-interval count trap-number
By default, OSPF outputs a maximum of seven SNMP notifications within 10 seconds.
Verifying and maintaining OSPF
Verifying OSPF configuration and running status
Verifying basic OSPF configuration and running status
Perform display tasks in any view.
•
Display OSPF process information. display ospf [ process-id ] [ verbose ]
•
Display OSPF ABR and ASBR information.
126
display ospf [ process-id ] abr-asbr [ verbose ]
•
Display the router ID-to-host name mapping table. display ospf [ process-id ] hostname-table
•
Display OSPF interface information. display ospf [ process-id ] interface [ interface-type interface-number | verbose ]
•
Display information about hello packets sent by an interface.
display ospf [ process-id ] interface [ interface-type interface-number ] hello
•
Display OSPF LSDB information. display ospf [ process-id ] lsdb [ brief | originate-router advertising-router-id | self-originate ] [ age { max-value max-age-value | min-value min-age-value } * ] [ resolve-hostname ] display ospf [ process-id ] lsdb hostname host-name [ age { max-value max-age-value | min-value min-age-value } * ] display ospf [ process-id ] lsdb { ase | opaque-as } [ link-state-id ]
[ originate-router advertising-router-id | self-originate ] [ age
{ max-value max-age-value | min-value min-age-value } * ]
[ resolve-hostname ] display ospf [ process-id ] lsdb { ase | opaque-as } [ link-state-id ] hostname host-name [ age { max-value max-age-value | min-value min-age-value } * ] display ospf [ process-id ] [ area area-id ] lsdb { asbr | network | nssa
| opaque-area | opaque-link | router | summary } [ link-state-id ]
[ originate-router advertising-router-id | self-originate ] [ age
{ max-value max-age-value | min-value min-age-value } * ]
[ resolve-hostname ] display ospf [ process-id ] [ area area-id ] lsdb { asbr | network | nssa
| opaque-area | opaque-link | router | summary } [ link-state-id ] hostname host-name [ age { max-value max-age-value | min-value min-age-value } * ]
•
Display OSPF next hop information. display ospf [ process-id ] nexthop
•
Display OSPF neighbor information. display ospf [ process-id ] peer [ hello | verbose ] [ interface-type interface-number ] [ [ neighbor-id ] [ resolve-hostname ] | hostname host-name ]
•
Display OSPF routing table information. display ospf [ process-id ] routing [ ip-address { mask-length | mask } ]
[ interface interface-type interface-number ] [ nexthop nexthop-address ] [ verbose ]
•
Display OSPF topology information. display ospf [ process-id ] [ area area-id ] spf-tree [ verbose ]
•
Display the global route ID. display router id [ vpn-instance vpn-instance-name ]
Verifying OSPF request queue and retransmission queue configuration
To display OSPF request queue information, execute the following command in any view:
127
display ospf [ process-id ] request-queue [ interface-type interface-number ] [ neighbor-id ]
To display OSPF retransmission queue information, execute the following command in any view: display ospf [ process-id ] retrans-queue [ interface-type interface-number ] [ neighbor-id ]
Verifying OSPF virtual link configuration
To display OSPF virtual link information, execute the following command in any view: display ospf [ process-id ] vlink
Verifying OSPF network reliability configuration and status
Perform display tasks in any view.
•
Display OSPF FRR backup next hop information. display ospf [ process-id ] [ area area-id ] fast-reroute lfa-candidate
•
Display OSPF GR information. display ospf [ process-id ] graceful-restart [ verbose ]
•
Display OSPF NSR information. display ospf [ process-id ] non-stop-routing status
Displaying and clearing OSPF statistics
Displaying OSPF statistics
Perform display tasks in any view.
•
Display global OSPF statistics. display ospf global-statistics [ public | vpn-instance vpn-instance-name ]
•
Display neighbor statistics for OSPF areas. display ospf [ process-id ] peer statistics
•
Display OSPF statistics. display ospf [ process-id ] statistics [ error | packet [ hello | interface-type interface-number ] ]
Clearing OSPF statistics
To clear OSPF statistics, execute the following command in user view: reset ospf [ process-id ] statistics
Verifying OSPF route summarization configuration
About this task
You can configure route summarization for OSPF inter-area or redistributed routes. Perform this task to view OSPF ABR or ASBR route summarization information.
Procedure
Perform display tasks in any view.
•
Display OSPF ABR route summarization information. display ospf [ process-id ] [ area area-id ] abr-summary [ ip-address
{ mask-length | mask } ] [ verbose ]
128
•
Display OSPF ASBR route summarization information. display ospf [ process-id ] asbr-summary [ ip-address { mask-length | mask } ]
Displaying and clearing GTSM discarded packet statistics
Displaying GTSM discarded packet statistics
To display GTSM discarded packet statistics, execute the following command in any view: display ttl-security statistics [ slot slot-number ]
For more information about the command, see "Advanced BGP commands."
Clearing GTSM discarded packet statistics
To clear GTSM discarded packet statistics, execute the following command in user view: reset ttl-security statistics [ slot slot-number ]
For more information about the command, see "Advanced BGP commands."
Displaying and clearing OSPF log information
Displaying OSPF log information
To display OSPF log information, execute the following command in any view: display ospf [ process-id ] event-log { lsa-flush | lsa-history [ verbose ]
| peer [ neighbor-id ] [ slot slot-number ] | route | spf }
Clearing OSPF log information
To clear OSPF log information, execute the following command in user view: reset ospf [ process-id ] event-log [ lsa-flush | lsa-history | peer [ slot slot-number ] | route | spf ]
Displaying and clearing OSPF hello packet log information
Displaying OSPF hello packet log information
To display OSPF hello packet log information, execute the following commands in any view: display ospf [ process-id ] event-log hello { received [ abnormal | dropped ]
| sent } [ neighbor-id ] [ slot slot-number ] display ospf [ process-id ] event-log hello sent { abnormal | failed }
[ neighbor-address ] [ slot slot-number ]
Clearing OSPF hello packet log information
To clear OSPF hello packet log information, execute the following command in user view: reset ospf [ process-id ] event-log hello { received [ abnormal | dropped ]
| sent [ abnormal | failed ] } [ slot slot-number ]
Maintaining OSPF
To restart an OSPF process, execute the following command in user view: reset ospf [ process-id ] process [ graceful-restart ]
129
To re-enable OSPF route redistribution, execute the following command in user view: reset ospf [ process-id ] redistribution
OSPF configuration examples
Example: Configuring basic OSPF
Network configuration
•
Enable OSPF on all devices, and split the AS into three areas.
•
Configure Device A and Device B as ABRs.
Figure 29 Network diagram
Device A
HGE1/0/1
10.1.1.1/24
Area 0
HGE1/0/1
10.1.1.2/24
HGE1/0/2
10.2.1.1/24
Device B
HGE1/0/2
10.3.1.1/24
Area 1 HGE1/0/1
10.2.1.2/24
Area 2
HGE1/0/1
10.3.1.2/24
Device C
HGE1/0/2
10.4.1.1/24
HGE1/0/2
10.5.1.1/24 Device D
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Device A.
<DeviceA> system-view
[DeviceA] router id 10.2.1.1
[DeviceA] ospf
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] quit
[DeviceA-ospf-1] area 1
[DeviceA-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.1] quit
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] router id 10.3.1.1
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] area 2
130
[DeviceB-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.2] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] router id 10.4.1.1
[DeviceC] ospf
[DeviceC-ospf-1] area 1
[DeviceC-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.1] network 10.4.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.1] quit
[DeviceC-ospf-1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] router id 10.5.1.1
[DeviceD] ospf
[DeviceD-ospf-1] area 2
[DeviceD-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.2] network 10.5.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.2] quit
[DeviceD-ospf-1] quit
Verifying the configuration
# Display the OSPF neighbors of Device A.
[DeviceA] display ospf peer verbose
OSPF Process 1 with Router ID 10.2.1.1
Neighbors
Area 0.0.0.0 interface 10.1.1.1(HundredGigE1/0/1)'s neighbors
Router ID: 10.3.1.1 Address: 10.1.1.2 GR State: Normal
State: Full Mode: Nbr is master Priority: 1
DR: 10.1.1.1 BDR: 10.1.1.2 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 37 sec
Neighbor is up for 06:03:59
Authentication Sequence: [ 0 ]
Neighbor state change count: 5
BFD status: Disabled
Area 0.0.0.1 interface 10.2.1.1(HundredGigE1/0/2)'s neighbors
Router ID: 10.4.1.1 Address: 10.2.1.2 GR State: Normal
State: Full Mode: Nbr is master Priority: 1
DR: 10.2.1.1 BDR: 10.2.1.2 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 32 sec
Neighbor is up for 06:03:12
Authentication Sequence: [ 0 ]
Neighbor state change count: 5
131
BFD status: Disabled
# Display OSPF routing information on Device A.
[DeviceA] display ospf routing
OSPF Process 1 with Router ID 10.2.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 1 Transit 10.2.1.1 10.2.1.1 0.0.0.1
10.3.1.0/24 2 Inter 10.1.1.2 10.3.1.1 0.0.0.0
10.4.1.0/24 2 Stub 10.2.1.2 10.4.1.1 0.0.0.1
10.5.1.0/24 3 Inter 10.1.1.2 10.3.1.1 0.0.0.0
10.1.1.0/24 1 Transit 10.1.1.1 10.2.1.1 0.0.0.0
Total nets: 5
Intra area: 3 Inter area: 2 ASE: 0 NSSA: 0
# Display OSPF routing information on Device D.
[DeviceD] display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 3 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.3.1.0/24 1 Transit 10.3.1.2 10.3.1.1 0.0.0.2
10.4.1.0/24 4 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.5.1.0/24 1 Stub 10.5.1.1 10.5.1.1 0.0.0.2
10.1.1.0/24 2 Inter 10.3.1.1 10.3.1.1 0.0.0.2
Total nets: 5
Intra area: 2 Inter area: 3 ASE: 0 NSSA: 0
# Ping 10.4.1.1 to test reachability.
[DeviceD] ping 10.4.1.1
Ping 10.4.1.1 (10.4.1.1): 56 data bytes, press CTRL+C to break
56 bytes from 10.4.1.1: icmp_seq=0 ttl=253 time=1.549 ms
56 bytes from 10.4.1.1: icmp_seq=1 ttl=253 time=1.539 ms
56 bytes from 10.4.1.1: icmp_seq=2 ttl=253 time=0.779 ms
56 bytes from 10.4.1.1: icmp_seq=3 ttl=253 time=1.702 ms
56 bytes from 10.4.1.1: icmp_seq=4 ttl=253 time=1.471 ms
--- Ping statistics for 10.4.1.1 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
132
round-trip min/avg/max/std-dev = 0.779/1.408/1.702/0.323 ms
Example: Configuring OSPF route redistribution
Network configuration
•
Enable OSPF on all the devices.
•
Split the AS into three areas.
•
Configure Device A and Device B as ABRs.
•
Configure Device C as an ASBR to redistribute external routes (static routes).
Figure 30 Network diagram
Device A
HGE1/0/1
10.1.1.1/24
Area 0
HGE1/0/1
10.1.1.2/24
HGE1/0/2
10.2.1.1/24
Device B
HGE1/0/2
10.3.1.1/24
Area 2
HGE1/0/1
10.3.1.2/24
Area 1 HGE1/0/1
10.2.1.2/24
Device C
HGE1/0/2
10.4.1.1/24
HGE1/0/2
10.5.1.1/24
Device D
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2.
Enable OSPF (see " Example: Configuring basic OSPF ").
3. Configure OSPF to redistribute routes:
# On Device C, configure a static route destined for network 3.1.2.0/24.
<DeviceC> system-view
[DeviceC] ip route-static 3.1.2.1 24 10.4.1.2
# On Device, configure OSPF to redistribute the static route.
[DeviceC] ospf 1
[DeviceC-ospf-1] import-route static
Verifying the configuration
# Display the ABR/ASBR information on Device D.
<DeviceD> display ospf abr-asbr
OSPF Process 1 with Router ID 10.5.1.1
Routing Table to ABR and ASBR
Topology base (MTID 0)
Type Destination Area Cost Nexthop RtType
Intra 10.3.1.1 0.0.0.2 10 10.3.1.1 ABR
Inter 10.4.1.1 0.0.0.2 22 10.3.1.1 ASBR
# Display the OSPF routing information on Device D.
133
<DeviceD> display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 22 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.3.1.0/24 10 Transit 10.3.1.2 10.3.1.1 0.0.0.2
10.4.1.0/24 25 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.5.1.0/24 10 Stub 10.5.1.1 10.5.1.1 0.0.0.2
10.1.1.0/24 12 Inter 10.3.1.1 10.3.1.1 0.0.0.2
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
3.1.2.0/24 1 Type2 1 10.3.1.1 10.4.1.1
Total nets: 6
Intra area: 2 Inter area: 3 ASE: 1 NSSA: 0
Example: Configuring OSPF route summarization
Network configuration
•
Configure OSPF on Device A and Device B in AS 200.
•
Configure OSPF on Device C, Device D, and Device E in AS 100.
•
Configure an EBGP connection between Device B and Device C. Configure Device and Device to redistribute OSPF routes and direct routes into BGP and BGP routes into OSPF.
•
Configure Device B to advertise only summary route 10.0.0.0/8 to Device A.
134
Figure 31 Network diagram
HGE1/0/2
10.3.1.1/24
Device D
HGE1/0/1
10.1.1.1/24
AS 100
HGE1/0/1
10.2.1.2/24
HGE1/0/1
10.1.1.2/24
Device C
HGE1/0/3
10.2.1.1/24
HGE1/0/2
11.1.1.2/24
EBGP
HGE1/0/2
11.1.1.1/24
Device B
Device E
HGE1/0/2
10.4.1.1/24
HGE1/0/1
11.2.1.2/24
HGE1/0/1
11.2.1.1/24
AS 200
Device A
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Device A.
<DeviceA> system-view
[DeviceA] router id 11.2.1.2
[DeviceA] ospf
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 11.2.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] quit
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] router id 11.2.1.1
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 11.2.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] router id 11.1.1.2
[DeviceC] ospf
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
135
# Configure Device D.
<DeviceD> system-view
[DeviceD] router id 10.3.1.1
[DeviceD] ospf
[DeviceD-ospf-1] area 0
[DeviceD-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.0] network 10.3.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.0] quit
[DeviceD-ospf-1] quit
# Configure Device E.
<DeviceE> system-view
[DeviceE] router id 10.4.1.1
[DeviceE] ospf
[DeviceE-ospf-1] area 0
[DeviceE-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[DeviceE-ospf-1-area-0.0.0.0] network 10.4.1.0 0.0.0.255
[DeviceE-ospf-1-area-0.0.0.0] quit
[DeviceE-ospf-1] quit
3. Configure BGP to redistribute OSPF routes and direct routes:
# Configure Device B.
[DeviceB] bgp 200
[DeviceB-bgp-default] peer 11.1.1.2 as-number 100
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 11.1.1.2 enable
[DeviceB-bgp-default-ipv4] import-route ospf
[DeviceB-bgp-default-ipv4] import-route direct
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C.
[DeviceC] bgp 100
[DeviceC-bgp-default] peer 11.1.1.1 as-number 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 11.1.1.1 enable
[DeviceC-bgp-default-ipv4] import-route ospf
[DeviceC-bgp-default-ipv4] import-route direct
[DeviceB-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
4. Configure Device B and Device C to redistribute BGP routes into OSPF:
# Configure OSPF to redistribute routes from BGP on Device B.
[DeviceB] ospf
[DeviceB-ospf-1] import-route bgp
# Configure OSPF to redistribute routes from BGP on Device C.
[DeviceC] ospf
[DeviceC-ospf-1] import-route bgp
# Display the IP routing table on Device A.
[DeviceA] display ip routing-table
Destinations : 16 Routes : 16
136
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.1.1.0/24 O_ASE2 150 1 11.2.1.1 HGE1/0/1
10.2.1.0/24 O_ASE2 150 1 11.2.1.1 HGE1/0/1
10.3.1.0/24 O_ASE2 150 1 11.2.1.1 HGE1/0/1
10.4.1.0/24 O_ASE2 150 1 11.2.1.1 HGE1/0/1
11.2.1.0/24 Direct 0 0 11.2.1.2 HGE1/0/1
11.2.1.0/32 Direct 0 0 11.2.1.2 HGE1/0/1
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.2.1.255/32 Direct 0 0 11.2.1.2 HGE1/0/1
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
5. Configure route summarization:
# Configure route summarization on Device B to advertise a single route 10.0.0.0/8.
[DeviceB-ospf-1] asbr-summary 10.0.0.0 8
# Display the IP routing table on Device A.
[DeviceA] display ip routing-table
Destinations : 13 Routes : 13
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/8 O_ASE2 150 1 11.2.1.1 HGE1/0/1
11.2.1.0/24 Direct 0 0 11.2.1.2 HGE1/0/1
11.2.1.0/32 Direct 0 0 11.2.1.2 HGE1/0/1
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.2.1.255/32 Direct 0 0 11.2.1.2 HGE1/0/1
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
The output shows that routes 10.1.1.0/24, 10.2.1.0/24, 10.3.1.0/24 and 10.4.1.0/24 are summarized into a single route 10.0.0.0/8.
Example: Configuring OSPF stub area
Network configuration
•
Enable OSPF on all devices, and split the AS into three areas.
137
•
Configure Device A and Device B as ABRs to forward routing information between areas.
•
Configure Device D as the ASBR to redistribute static routes.
•
Configure Area 1 as a stub area to reduce advertised LSAs without influencing reachability.
Figure 32 Network diagram
Device A
HGE1/0/1
10.1.1.1/24
Area 0
HGE1/0/2
10.2.1.1/24
HGE1/0/1
10.1.1.2/24
Device B
HGE1/0/2
10.3.1.1/24
Area 1
Stub
HGE1/0/1
10.2.1.2/24
Device C
HGE1/0/2
10.4.1.1/24
Area 2
HGE1/0/1
10.3.1.2/24
ASBR
HGE1/0/2
10.5.1.1/24 Device D
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2.
Enable OSPF (see " Example: Configuring basic OSPF ").
3. Configure route redistribution:
# Configure Device D to redistribute static routes.
<DeviceD> system-view
[DeviceD] ip route-static 3.1.2.1 24 10.5.1.2
[DeviceD] ospf
[DeviceD-ospf-1] import-route static
[DeviceD-ospf-1] quit
# Display ABR/ASBR information on Device C.
<DeviceC> display ospf abr-asbr
OSPF Process 1 with Router ID 10.4.1.1
Routing Table to ABR and ASBR
Topology base (MTID 0)
Type Destination Area Cost Nexthop RtType
Intra 10.2.1.1 0.0.0.1 3 10.2.1.1 ABR
Inter 10.5.1.1 0.0.0.1 7 10.2.1.1 ASBR
# Display OSPF routing information on Device C.
<DeviceC> display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
138
10.2.1.0/24 3 Transit 0.0.0.0 10.2.1.1 0.0.0.1
10.3.1.0/24 7 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.4.1.0/24 3 Stub 10.4.1.1 10.4.1.1 0.0.0.1
10.5.1.0/24 17 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.1.1.0/24 5 Inter 10.2.1.1 10.2.1.1 0.0.0.1
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
3.1.2.0/24 1 Type2 1 10.2.1.1 10.5.1.1
Total nets: 6
Intra area: 2 Inter area: 3 ASE: 1 NSSA: 0
The output shows that Device C's routing table contains an AS external route.
4. Configure Area 1 as a stub area:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf
[DeviceA-ospf-1] area 1
[DeviceA-ospf-1-area-0.0.0.1] stub
[DeviceA-ospf-1-area-0.0.0.1] quit
[DeviceA-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf
[DeviceC-ospf-1] area 1
[DeviceC-ospf-1-area-0.0.0.1] stub
[DeviceC-ospf-1-area-0.0.0.1] quit
[DeviceC-ospf-1] quit
# Display OSPF routing information on Device C.
[DeviceC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
0.0.0.0/0 4 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.2.1.0/24 3 Transit 0.0.0.0 10.2.1.1 0.0.0.1
10.3.1.0/24 7 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.4.1.0/24 3 Stub 10.4.1.1 10.4.1.1 0.0.0.1
10.5.1.0/24 17 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.1.1.0/24 5 Inter 10.2.1.1 10.2.1.1 0.0.0.1
Total nets: 6
Intra area: 2 Inter area: 4 ASE: 0 NSSA: 0
The output shows that a default route replaces the AS external route.
139
# Configure Area 1 as a totally stub area.
[DeviceA] ospf
[DeviceA-ospf-1] area 1
[DeviceA-ospf-1-area-0.0.0.1] stub no-summary
[DeviceA-ospf-1-area-0.0.0.1] quit
# Display OSPF routing information on Device C.
[DeviceC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
0.0.0.0/0 4 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.2.1.0/24 3 Transit 0.0.0.0 10.4.1.1 0.0.0.1
10.4.1.0/24 3 Stub 10.4.1.1 10.4.1.1 0.0.0.1
Total nets: 3
Intra area: 2 Inter area: 1 ASE: 0 NSSA: 0
The output shows that inter-area routes are removed, and only one external route (a default route) exists on Device C.
Example: Configuring OSPF NSSA area
Network configuration
•
Configure OSPF on all devices and split AS into three areas.
•
Configure Device A and Device B as ABRs to forward routing information between areas.
•
Configure Area 1 as an NSSA area and configure Device C as an ASBR to redistribute static routes into the AS.
Figure 33 Network diagram
Device A
HGE1/0/1
10.1.1.1/24
Area 0
HGE1/0/1
10.1.1.2/24
HGE1/0/2
10.2.1.1/24
Device B
HGE1/0/2
10.3.1.1/24
Area 1
NSSA
HGE1/0/1
10.2.1.2/24
ASBR
Device C
HGE1/0/2
10.4.1.1/24
Area 2
HGE1/0/2
10.5.1.1/24
HGE1/0/1
10.3.1.2/24
Device D
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
140
2.
Enable OSPF (see " Example: Configuring basic OSPF ").
3. Configure Area 1 as an NSSA area:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf
[DeviceA-ospf-1] area 1
[DeviceA-ospf-1-area-0.0.0.1] nssa
[DeviceA-ospf-1-area-0.0.0.1] quit
[DeviceA-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf
[DeviceC-ospf-1] area 1
[DeviceC-ospf-1-area-0.0.0.1] nssa
[DeviceC-ospf-1-area-0.0.0.1] quit
[DeviceC-ospf-1] quit
# Display routing information on Device C.
[DeviceC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 3 Transit 10.2.1.2 10.4.1.1 0.0.0.1
10.3.1.0/24 7 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.4.1.0/24 3 Stub 10.4.1.1 10.4.1.1 0.0.0.1
10.5.1.0/24 17 Inter 10.2.1.1 10.2.1.1 0.0.0.1
10.1.1.0/24 5 Inter 10.2.1.1 10.2.1.1 0.0.0.1
Total nets: 5
Intra area: 2 Inter area: 3 ASE: 0 NSSA: 0
4. Configure route redistribution:
# Configure OSPF to redistribute the static route on Device C.
[DeviceC] ip route-static 3.1.2.1 24 10.4.1.2
[DeviceC] ospf
[DeviceC-ospf-1] import-route static
[DeviceC-ospf-1] quit
# Display routing information on Device D.
<DeviceD> display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Table
Topology base (MTID 0)
141
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 22 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.3.1.0/24 10 Transit 10.3.1.2 10.3.1.1 0.0.0.2
10.4.1.0/24 25 Inter 10.3.1.1 10.3.1.1 0.0.0.2
10.5.1.0/24 10 Stub 10.5.1.1 10.5.1.1 0.0.0.2
10.1.1.0/24 12 Inter 10.3.1.1 10.3.1.1 0.0.0.2
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
3.1.2.0/24 1 Type2 1 10.3.1.1 10.2.1.1
Total nets: 6
Intra area: 2 Inter area: 3 ASE: 1 NSSA: 0
The output shows that an AS external route imported from the NSSA area exists on Device D.
Example: Configuring OSPF DR election
Network configuration
•
Enable OSPF on Devices A, B, C, and D on the same network.
•
Configure Device D as the DR, and configure Device C as the BDR.
•
Change the device priorities on the interfaces to configure Device A as the DR and Device C as the BDR.
Figure 34 Network diagram
Device A Device B
HGE1/0/1
192.168.1.1/24
HGE1/0/1
192.168.1.2/24
HGE1/0/1
192.168.1.3/24
HGE1/0/1
192.168.1.4/24
Device C Device D
Restrictions and guidelines
If the network already has a DR or BDR, the device priority settings configured on interfaces do not take effect immediately.
The Full neighbor state means an adjacency has been established. The 2-Way neighbor state means the two devices are not the DR or BDR, and they do not exchange LSAs.
The interface state DROther means the interface is not the DR or BDR.
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2.
Configure basic OSPF settings on all devices (see " Example: Configuring basic OSPF ").
142
3. Display neighbor information on Device A.
[DeviceA] display ospf peer verbose
OSPF Process 1 with Router ID 1.1.1.1
Neighbors
Area 0.0.0.0 interface 192.168.1.1(HundredGigE1/0/1)'s neighbors
Router ID: 2.2.2.2 Address: 192.168.1.2 GR State: Normal
State: 2-Way Mode: None Priority: 1
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 38 sec
Neighbor is up for 00:01:31
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 3.3.3.3 Address: 192.168.1.3 GR State: Normal
State: Full Mode: Nbr is master Priority: 1
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 31 sec
Neighbor is up for 00:01:28
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 4.4.4.4 Address: 192.168.1.4 GR State: Normal
State: Full Mode: Nbr is master Priority: 1
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 31 sec
Neighbor is up for 00:01:28
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
The output shows that Device D is the DR and Device C is the BDR.
4. Configure device priorities on interfaces:
# Configure Device A.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospf dr-priority 100
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] quit
# Configure Device B.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospf dr-priority 0
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] quit
143
# Configure Device C.
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospf dr-priority 2
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] quit
# Display information about neighbors of Device D.
<DeviceD> display ospf peer verbose
OSPF Process 1 with Router ID 4.4.4.4
Neighbors
Area 0.0.0.0 interface 192.168.1.4(HundredGigE1/0/1)'s neighbors
Router ID: 1.1.1.1 Address: 192.168.1.1 GR State: Normal
State: Full Mode:Nbr is slave Priority: 100
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 31 sec
Neighbor is up for 00:11:17
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 2.2.2.2 Address: 192.168.1.2 GR State: Normal
State: Full Mode:Nbr is slave Priority: 0
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 35 sec
Neighbor is up for 00:11:19
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 3.3.3.3 Address: 192.168.1.3 GR State: Normal
State: Full Mode:Nbr is slave Priority: 2
DR: 192.168.1.4 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 33 sec
Neighbor is up for 00:11:15
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
The output shows that the DR and BDR are not changed.
5. Restart OSPF processes:
# Restart the OSPF process on Device A.
<DeviceA> reset ospf 1 process
Warning : Reset OSPF process? [Y/N]:y
# Restart the OSPF process on Device B.
<DeviceB> reset ospf 1 process
144
Warning : Reset OSPF process? [Y/N]:y
# Restart the OSPF process on Device C.
<DeviceC> reset ospf 1 process
Warning : Reset OSPF process? [Y/N]:y
# Restart the OSPF process on Device D.
<DeviceD> reset ospf 1 process
Warning : Reset OSPF process? [Y/N]:y
# Display neighbor information on Device D.
<DeviceD> display ospf peer verbose
OSPF Process 1 with Router ID 4.4.4.4
Neighbors
Area 0.0.0.0 interface 192.168.1.4(HundredGigE1/0/1)'s neighbors
Router ID: 1.1.1.1 Address: 192.168.1.1 GR State: Normal
State: Full Mode: Nbr is slave Priority: 100
DR: 192.168.1.1 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 39 sec
Neighbor is up for 00:01:40
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 2.2.2.2 Address: 192.168.1.2 GR State: Normal
State: 2-Way Mode: None Priority: 0
DR: 192.168.1.1 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 35 sec
Neighbor is up for 00:01:44
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
Router ID: 3.3.3.3 Address: 192.168.1.3 GR State: Normal
State: Full Mode: Nbr is slave Priority: 2
DR: 192.168.1.1 BDR: 192.168.1.3 MTU: 0
Options is 0x02 (-|-|-|-|-|-|E|-)
Dead timer due in 39 sec
Neighbor is up for 00:01:41
Authentication Sequence: [ 0 ]
Neighbor state change count: 6
BFD status: Disabled
The output shows that Device A becomes the DR and Device C becomes the BDR.
# Display OSPF interface information.
<DeviceA> display ospf interface
OSPF Process 1 with Router ID 1.1.1.1
145
Interfaces
Area: 0.0.0.0
IP Address Type State Cost Pri DR BDR
192.168.1.1 Broadcast DR 1 100 192.168.1.1 192.168.1.3
[DeviceB] display ospf interface
OSPF Process 1 with Router ID 2.2.2.2
Interfaces
Area: 0.0.0.0
IP Address Type State Cost Pri DR BDR
192.168.1.2 Broadcast DROther 1 0 192.168.1.1 192.168.1.3
Example: Configuring OSPF virtual link
Network configuration
As shown in Figure 35 , configure a virtual link between Device B and Device C to connect Area 2 to
the backbone area. After configuration, Device B can learn routes to Area 2.
Figure 35 Network diagram
Area 1
Virtual link
Device D
HGE1/0/1
10.3.1.1/24
HGE1/0/2
10.3.1.2/24
Area 2
Device C
HGE1/0/1
10.2.1.2/24
Device B
HGE1/0/2
10.2.1.1/24
Area 0
HGE1/0/1
10.1.1.2/24
HGE1/0/1
10.1.1.1/24
Device A
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf 1 router-id 1.1.1.1
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] quit
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf 1 router-id 2.2.2.2
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] area 1
146
[DeviceB–ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[DeviceB–ospf-1-area-0.0.0.1] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf 1 router-id 3.3.3.3
[DeviceC-ospf-1] area 1
[DeviceC-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.1] quit
[DeviceC-ospf-1] area 2
[DeviceC–ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[DeviceC–ospf-1-area-0.0.0.2] quit
[DeviceC-ospf-1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] ospf 1 router-id 4.4.4.4
[DeviceD-ospf-1] area 2
[DeviceD-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.2] quit
[DeviceD-ospf-1] quit
# Display OSPF routing information on Device B.
[DeviceB] display ospf routing
OSPF Process 1 with Router ID 2.2.2.2
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 2 Transit 10.2.1.1 3.3.3.3 0.0.0.1
10.1.1.0/24 2 Transit 10.1.1.2 2.2.2.2 0.0.0.0
Total nets: 2
Intra area: 2 Inter area: 0 ASE: 0 NSSA: 0
The output shows that Device B does not have routes to Area 2 because Area 0 is not directly connected to Area 2.
3. Configure a virtual link:
# Configure Device B.
[DeviceB] ospf
[DeviceB-ospf-1] area 1
[DeviceB-ospf-1-area-0.0.0.1] vlink-peer 3.3.3.3
[DeviceB-ospf-1-area-0.0.0.1] quit
[DeviceB-ospf-1] quit
# Configure Device C.
[DeviceC] ospf
[DeviceC-ospf-1] area 1
[DeviceC-ospf-1-area-0.0.0.1] vlink-peer 2.2.2.2
[DeviceC-ospf-1-area-0.0.0.1] quit
147
[DeviceC-ospf-1] quit
# Display OSPF routing information on Device B.
[DeviceB] display ospf routing
OSPF Process 1 with Router ID 2.2.2.2
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 2 Transit 10.2.1.1 3.3.3.3 0.0.0.1
10.3.1.0/24 5 Inter 10.2.1.2 3.3.3.3 0.0.0.0
10.1.1.0/24 2 Transit 10.1.1.2 2.2.2.2 0.0.0.0
Total nets: 3
Intra area: 2 Inter area: 1 ASE: 0 NSSA: 0
The output shows that Device B has learned the route 10.3.1.0/24 to Area 2.
Example: Configuring OSPF GR
Network configuration
•
Device A, Device B, and Device C that belong to the same autonomous system and the same
OSPF routing domain are GR capable.
•
Device A acts as the non-IETF GR restarter. Device B and Device C are the GR helpers, and synchronize their LSDBs with Device A through OOB communication of GR.
Figure 36 Network diagram
Router ID: 1.1.1.1
GR restarter
Device A
HGE1/0/1
192.1.1.1/24
HGE1/0/1
192.1.1.2/24
HGE1/0/1
192.1.1.3/24
Device B Device C
GR helper
Router ID: 2.2.2.2
GR helper
Router ID: 3.3.3.3
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Device A.
<DeviceA> system-view
148
[DeviceA] router id 1.1.1.1
[DeviceA] ospf 100
[DeviceA-ospf-100] area 0
[DeviceA-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[DeviceA-ospf-100-area-0.0.0.0] quit
[DeviceA-ospf-100] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] router id 2.2.2.2
[DeviceB] ospf 100
[DeviceB-ospf-100] area 0
[DeviceB-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[DeviceB-ospf-100-area-0.0.0.0] quit
[DeviceB-ospf-100] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] router id 3.3.3.3
[DeviceC] ospf 100
[DeviceC-ospf-100] area 0
[DeviceC-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[DeviceC-ospf-100-area-0.0.0.0] quit
[DeviceC-ospf-100] quit
3. Configure OSPF GR:
# Configure Device A as the non-IETF OSPF GR restarter: enable the link-local signaling capability, the out-of-band re-synchronization capability, and non-IETF GR for OSPF process
100.
[DeviceA-ospf-100] enable link-local-signaling
[DeviceA-ospf-100] enable out-of-band-resynchronization
[DeviceA-ospf-100] graceful-restart
[DeviceA-ospf-100] quit
# Configure Device B as the GR helper: enable the link-local signaling capability and the out-of-band re-synchronization capability for OSPF process 100.
[DeviceB-ospf-100] enable link-local-signaling
[DeviceB-ospf-100] enable out-of-band-resynchronization
# Configure Device C as the GR helper: enable the link-local signaling capability and the out-of-band re-synchronization capability for OSPF process 100.
[DeviceC-ospf-100] enable link-local-signaling
[DeviceC-ospf-100] enable out-of-band-resynchronization
Verifying the configuration
# Enable OSPF GR event debugging and restart the OSPF process by using GR on Device A.
<DeviceA> debugging ospf event graceful-restart
<DeviceA> terminal monitor
<DeviceA> terminal logging level 7
<DeviceA> reset ospf 100 process graceful-restart
Reset OSPF process? [Y/N]:y
%Oct 21 15:29:28:727 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(HundredGigE1/0/1) from Full to Down.
149
%Oct 21 15:29:28:729 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(HundredGigE1/0/1) from Full to Down.
*Oct 21 15:29:28:735 2011 RouterA OSPF/7/DEBUG:
OSPF 100 nonstandard GR Started for OSPF Router
*Oct 21 15:29:28:735 2011 RouterA OSPF/7/DEBUG:
OSPF 100 created GR wait timer,timeout interval is 40(s).
*Oct 21 15:29:28:735 2011 RouterA OSPF/7/DEBUG:
OSPF 100 created GR Interval timer,timeout interval is 120(s).
*Oct 21 15:29:28:758 2011 RouterA OSPF/7/DEBUG:
OSPF 100 created OOB Progress timer for neighbor 192.1.1.3.
*Oct 21 15:29:28:766 2011 RouterA OSPF/7/DEBUG:
OSPF 100 created OOB Progress timer for neighbor 192.1.1.2.
%Oct 21 15:29:29:902 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(HundredGigE1/0/1) from Loading to Full.
*Oct 21 15:29:29:902 2011 RouterA OSPF/7/DEBUG:
OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.2.
%Oct 21 15:29:30:897 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(HundredGigE1/0/1) from Loading to Full.
*Oct 21 15:29:30:897 2011 RouterA OSPF/7/DEBUG:
OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.3.
*Oct 21 15:29:30:911 2011 RouterA OSPF/7/DEBUG:
OSPF GR: Process 100 Exit Restart,Reason : DR or BDR change,for neighbor : 192.1.1.3.
*Oct 21 15:29:30:911 2011 RouterA OSPF/7/DEBUG:
OSPF 100 deleted GR Interval timer.
*Oct 21 15:29:30:912 2011 RouterA OSPF/7/DEBUG:
OSPF 100 deleted GR wait timer.
%Oct 21 15:29:30:920 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(HundredGigE1/0/1) from Full to Down.
%Oct 21 15:29:30:921 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(HundredGigE1/0/1) from Full to Down.
%Oct 21 15:29:33:815 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(HundredGigE1/0/1) from Loading to Full.
%Oct 21 15:29:35:578 2011 RouterA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(HundredGigE1/0/1) from Loading to Full.
The output shows that Device A completes GR.
Example: Configuring OSPF NSR
Network configuration
As shown in Figure 37 , Device S, Device A, and Device B belong to the same OSPF routing domain.
Enable OSPF NSR on Device S to ensure correct routing when an active/standby switchover occurs on Device S.
Figure 37 Network diagram
Loop 0
22.22.22.22/32
Device A
HGE1/0/1
12.12.12.1/24
HGE1/0/1
12.12.12.2/24
Device S
HGE1/0/1
14.14.14.1/24
HGE1/0/2
14.14.14.2/24
Device B
Loop 0
44.44.44.44/32
150
Procedure
1. Configure IP addresses and subnet masks for interfaces on the routers. (Details not shown.)
2. Configure OSPF on the devices to ensure the following: (Details not shown.)
Device S, Device A, and Device B can communicate with each other at Layer 3.
Dynamic route update can be implemented among them with OSPF.
3. Enable OSPF NSR on Device S.
<DeviceS> system-view
[DeviceS] ospf 100
[DeviceS-ospf-100] non-stop-routing
[DeviceS-ospf-100] quit
Verifying the configuration
# Perform an active/standby switchover on Device S.
[DeviceS] placement reoptimize
Predicted changes to the placement
Service Group(instance name) Cur location New location
---------------------------------------------------------------------------- rib 0/0 0/0 staticroute 0/0 0/0 ospf 0/0 1/0
Continue? [y/n]:y
Re-optimization of the placement start. You will be notified on completion.
Re-optimization of the placement complete. Use 'display placement' to view the new placement.
# During the switchover period, display OSPF neighbors on Device A to verify the neighbor relationship between Device A and Device S.
<DeviceA> display ospf peer
OSPF Process 1 with Router ID 2.2.2.1
Neighbor Brief Information
Area: 0.0.0.0
Router ID Address Pri Dead-Time State Interface
3.3.3.1 12.12.12.2 1 37 Full/BDR HGE1/0/1
# Display OSPF routes on Device A to verify if Device A has a route to the loopback interface on
Device B.
<DeviceA> display ospf routing
OSPF Process 1 with Router ID 2.2.2.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
44.44.44.44/32 2 Stub 12.12.12.2 4.4.4.1 0.0.0.0
14.14.14.0/24 2 Transit 12.12.12.2 4.4.4.1 0.0.0.0
22.22.22.22/32 0 Stub 22.22.22.22 2.2.2.1 0.0.0.0
151
12.12.12.0/24 1 Transit 12.12.12.1 2.2.2.1 0.0.0.0
Total nets: 4
Intra area: 4 Inter area: 0 ASE: 0 NSSA: 0
# Display OSPF neighbors on Device B to verify the neighbor relationship between Device B and
Device S.
<DeviceB> display ospf peer
OSPF Process 1 with Router ID 4.4.4.1
Neighbor Brief Information
Area: 0.0.0.0
Router ID Address Pri Dead-Time State Interface
3.3.3.1 14.14.14.2 1 39 Full/BDR HGE1/0/1
# Display OSPF routes on Device B to verify if Device B has a route to the loopback interface on
Device A.
<DeviceB> display ospf routing
OSPF Process 1 with Router ID 4.4.4.1
Routing Table
Topology base (MTID 0)
Routing for network
Destination Cost Type NextHop AdvRouter Area
44.44.44.44/32 0 Stub 44.44.44.44 4.4.4.1 0.0.0.0
14.14.14.0/24 1 Transit 14.14.14.1 4.4.4.1 0.0.0.0
22.22.22.22/32 2 Stub 14.14.14.2 2.2.2.1 0.0.0.0
12.12.12.0/24 2 Transit 14.14.14.2 2.2.2.1 0.0.0.0
Total nets: 4
Intra area: 4 Inter area: 0 ASE: 0 NSSA: 0
The output shows the following when an active/standby switchover occurs on Device S:
•
The neighbor relationships and routing information on Device A and Device B have not changed.
•
The traffic from Device A to Device B has not been impacted.
Example: Configuring BFD for OSPF
Network configuration
As shown in Figure 38 , run OSPF on Device A, Device B, and Device C so that they can reach each
other at the network layer.
•
When the link over which Device A and Device B communicate through a Layer 2 switch fails,
BFD can quickly detect the failure and notify OSPF of the failure.
•
Device A and Device B then communicate through Device C.
152
Figure 38 Network diagram
Loop0
Device A
HGE1/0/1
HGE1/0/2
BFD
HGE1/0/1
Device B
L2 Switch HGE1/0/2
Loop0
Area 0
HGE1/0/1 HGE1/0/2
Device C
Table 9 Interface and IP address assignment
Device
Device A
Device A
Device A
Device B
Device B
Device B
Device C
Interface
HGE1/0/1
HGE1/0/2
Loop0
HGE1/0/1
HGE1/0/2
Loop0
HGE1/0/1
IP address
192.168.0.102/24
10.1.1.102/24
121.1.1.1/32
192.168.0.100/24
13.1.1.1/24
120.1.1.1/32
10.1.1.100/24
Device C
Procedure
HGE1/0/2 13.1.1.2/24
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 192.168.0.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] network 121.1.1.1 0.0.0.0
[DeviceA-ospf-1-area-0.0.0.0] quit
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 192.168.0.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] network 13.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] network 120.1.1.1 0.0.0.0
[DeviceB-ospf-1-area-0.0.0.0] quit
153
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] network 13.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
3. Configure BFD:
# Enable BFD on Device A and configure BFD parameters.
[DeviceA] bfd session init-mode active
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospf bfd enable
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 7
[DeviceA-HundredGigE1/0/1] quit
# Enable BFD on Device B and configure BFD parameters.
[DeviceB] bfd session init-mode active
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospf bfd enable
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 6
[DeviceB-HundredGigE1/0/1] quit
Verifying the configuration
# Display the BFD information on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 Session Working Under Ctrl Mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
3/1 192.168.0.102 192.168.0.100 Up 1700ms HGE1/0/1
# Display routes destined for 120.1.1.1/32 on Device A.
<DeviceA> display ip routing-table 120.1.1.1 verbose
Summary count : 1
Destination: 120.1.1.1/32
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 10
IpPre: N/A QosLocalID: N/A
154
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 192.168.0.100
Label: NULL RealNextHop: 192.168.0.100
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display routes destined for 120.1.1.1/32 on Device A.
<DeviceA> display ip routing-table 120.1.1.1 verbose
Summary count : 1
Destination: 120.1.1.1/32
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 2 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 10.1.1.100
Label: NULL RealNextHop: 10.1.1.100
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
155
Example: Configuring OSPF FRR
Network configuration
As shown in Figure 39 , Device A, Device B, and Device C reside in the same OSPF domain.
Configure OSPF FRR so that when Link A fails, traffic is immediately switched to Link B.
Figure 39 Network diagram
Device C
HGE
1/0
/1
Link B
HGE
1/0
/2
HGE
1/0
/1
Link A
Loop0
Device A
HGE1/0/2
Table 10 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Device A
Device A
Device B
Device B
Device B
Device C
Interface
HGE1/0/1
HGE1/0/2
Loop0
HGE1/0/1
HGE1/0/2
Loop0
HGE1/0/1
IP address
12.12.12.1/24
13.13.13.1/24
1.1.1.1/32
24.24.24.4/24
13.13.13.2/24
4.4.4.4/32
12.12.12.2/24
Device C HGE1/0/2 24.24.24.2/24
Procedure
1. Configure IP addresses and subnet masks for interfaces on the routers. (Details not shown.)
2. Configure OSPF on the devices to ensure that Device A, Device B, and Device C can communicate with each other at the network layer. (Details not shown.)
3. Configure OSPF FRR:
You can enable OSPF FRR to either calculate a backup next hop by using the LFA algorithm, or specify a backup next hop by using a routing policy.
(Method 1.) Enable OSPF FRR to calculate a backup next hop by using the LFA algorithm:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospf 1
[DeviceA-ospf-1] fast-reroute lfa
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf 1
[DeviceB-ospf-1] fast-reroute lfa
[DeviceB-ospf-1] quit
156
(Method 2.) Enable OSPF FRR to specify a backup next hop by using a routing policy:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ip prefix-list abc index 10 permit 4.4.4.4 32
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ip address prefix-list abc
[DeviceA-route-policy-frr-10] apply fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 12.12.12.2
[DeviceA-route-policy-frr-10] quit
[DeviceA] ospf 1
[DeviceA-ospf-1] fast-reroute route-policy frr
[DeviceA-ospf-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ip prefix-list abc index 10 permit 1.1.1.1 32
[DeviceB] route-policy frr permit node 10
[DeviceB-route-policy-frr-10] if-match ip address prefix-list abc
[DeviceB-route-policy-frr-10] apply fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 24.24.24.2
[DeviceB-route-policy-frr-10] quit
[DeviceB] ospf 1
[DeviceB-ospf-1] fast-reroute route-policy frr
[DeviceB-ospf-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Device A to view the backup next hop information.
[DeviceA] display ip routing-table 4.4.4.4 verbose
Summary count : 1
Destination: 4.4.4.4/32
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.2
Label: NULL RealNextHop: 13.13.13.2
BkLabel: NULL BkNextHop: 12.12.12.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
157
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display route 1.1.1.1/32 on Device B to view the backup next hop information.
[DeviceB] display ip routing-table 1.1.1.1 verbose
Summary count : 1
Destination: 1.1.1.1/32
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.1
Label: NULL RealNextHop: 13.13.13.1
BkLabel: NULL BkNextHop: 24.24.24.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
Troubleshooting OSPF configuration
No OSPF neighbor relationship established
Symptom
No OSPF neighbor relationship can be established.
Analysis
Solution
If the physical link and lower layer protocols work correctly, verify OSPF parameters configured on interfaces. Two neighbors must have the same parameters, such as the area ID, network segment, and mask. (A P2P or virtual link can have different network segments and masks.)
To resolve the problem:
1. Use the display ospf peer command to verify OSPF neighbor information.
158
2. Use the display ospf interface command to verify OSPF interface information.
3. Ping the neighbor router's IP address to verify that the connectivity is normal.
4. Verify OSPF timers. The dead interval on an interface must be a minimum of four times the hello interval.
5. On an NBMA network, use the peer ip-address command to manually specify the neighbor.
6. A minimum of one interface must have a router priority higher than 0 on an NBMA or a broadcast network.
7. If the problem persists, contact Hewlett Packard Enterprise Support.
Incorrect routing information
Symptom
OSPF cannot find routes to other areas.
Analysis
The backbone area must maintain connectivity to all other areas. If a router connects to more than one area, a minimum of one area must be connected to the backbone. The backbone cannot be configured as a stub area.
In a stub area, all routers cannot receive external routes, and all interfaces connected to the stub area must belong to the stub area.
Solution
To resolve the problem:
1. Use the display ospf peer command to verify neighbor information.
2. Use the display ospf interface command to verify OSPF interface information.
3. Use the display ospf lsdb command to verify the LSDB.
4. Use the display current-configuration configuration ospf command to verify area configuration. If more than two areas are configured, a minimum of one area is connected to the backbone.
5. In a stub area, all routers attached are configured with the stub command. In an NSSA area, all routers attached are configured with the nssa command.
6. If a virtual link is configured, use the display ospf vlink command to verify the state of the virtual link.
7. If the problem persists, contact Hewlett Packard Enterprise Support.
159
Configuring IS-IS
About IS-IS
IS-IS is an IGP used within an AS. It uses the SPF algorithm for route calculation.
Terminology
•
Intermediate system —Similar to a router in TCP/IP, IS is the basic unit used in an IS-IS routing domain to generate and propagate routing information. Throughout this chapter, an IS refers to a router.
•
End system —Similar to a host in TCP/IP, an ES does not run IS-IS. ISO defines the ES-IS protocol for communication between an ES and an IS.
•
Routing domain —An RD comprises a group of ISs that exchange routing information with each other by using the same routing protocol.
•
Area —An IS-IS routing domain can be split into multiple areas.
•
Link State Database —All link states in the network form the LSDB. Each IS has a minimum of one LSDB. An IS uses the SPF algorithm and LSDB to generate IS-IS routes.
•
Link State Protocol Data Unit or Link State Packet —An IS advertises link state information in an LSP.
•
Network Protocol Data Unit —An NPDU is a network layer protocol packet in OSI, similar to an IP packet in TCP/IP.
•
Designated IS —A DIS is elected on a broadcast network.
•
Network service access point —An NSAP is an OSI network layer address. The NSAP identifies an abstract network service access point and describes the network address format in the OSI reference model.
IS-IS address
As shown in Figure 40 , an NSAP address comprises the Initial Domain Part (IDP) and the Domain
Specific Part (DSP). The IDP is analogous to the network ID of an IP address, and the DSP is analogous to the subnet and host ID.
The IDP includes the Authority and Format Identifier (AFI) and the Initial Domain Identifier (IDI).
The DSP includes:
•
High Order Part of DSP (HO-DSP) — Identifies the area.
•
System ID —Identifies the host.
•
SEL —Also known as the N-SEL or the NSAP selector (SEL). It is similar to the protocol identifier in IP and is used to identify the type of service. Different transport layer protocols correspond to different SELs.
The IDP and DSP are variable in length. The length of an NSAP address is in the range of 8 to 20 bytes.
160
Figure 40 NSAP address format
AFI
IDP
IDI HO-DSP
DSP
System ID (6 octet) SEL (1 octet)
Area address
An IS-IS address contains the following components:
•
Area address
The area address comprises the IDP and the HO-DSP of the DSP, which identify the area and the routing domain. Different routing domains cannot have the same area address.
Typically, a router only needs one area address, and all nodes in the same area must have the same area address. To support smooth area merging, partitioning, and switching, a router can have a maximum of three area addresses.
•
System ID
A system ID uniquely identifies a host or router. It has a fixed length of 48 bits (6 bytes).
The system ID of a device can be generated from the router ID. For example, suppose a router uses the IP address 168.10.1.1 of Loopback 0 as the router ID. The system ID can be obtained in the following steps: a. Extend each decimal number of the IP address to three digits by adding 0s from the left, such as 168.010.001.001. b. Divide the extended IP address into three sections that each has four digits to get the system ID 1680.1000.1001.
If you use other methods to define a system ID, make sure that it can uniquely identify the host or router.
•
SEL
An SEL is used to identify the type of service. Different transport layer protocols correspond to different SELs. It has a fixed length of 8 bits. All SELs in IP are 00.
NET
A network entity title (NET) identifies the network layer information of an IS. It does not include transport layer information. A NET is a special NSAP address with the SEL being 0. The length of a
NET is in the range of 8 to 20 bytes, same as a NSAP address.
A NET includes the following parts:
•
Area ID —Has a length of 1 to 13 bytes.
•
System ID —A system ID uniquely identifies a host or router in the area and has a fixed length of 6 bytes.
•
SEL —Has a value of 0 and a fixed length of 1 byte.
For example, for a NET ab.cdef.1234.5678.9abc.00, the area ID is ab.cdef, the system ID is
1234.5678.9abc, and the SEL is 00.
Typically, a router only needs one NET, but it can have a maximum of three NETs for smooth area merging and partitioning. When you configure multiple NETs, make sure the system IDs are the same.
161
IS-IS area
IS-IS has a 2-level hierarchy to support large-scale networks. A large-scale routing domain is divided into multiple areas. Typically, a Level-1 router is deployed within an area. A Level-2 router is deployed between areas. A Level-1-2 router is deployed between Level-1 and Level-2 routers.
Level-1 router
A Level-1 router establishes neighbor relationships with Level-1 and Level-1-2 routers in the same area. It maintains an LSDB comprising intra-area routing information. A Level-1 router forwards packets destined for external areas to the nearest Level-1-2 router. Level-1 routers in different areas cannot establish neighbor relationships.
Level-2 router
A Level-2 router establishes neighbor relationships with Level-2 and Level-1-2 routers in the same area or in different areas. It maintains a Level-2 LSDB containing inter-area routing information. All the Level-2 and Level-1-2 routers must be contiguous to form the backbone of the IS-IS routing domain. Level-2 routers can establish neighbor relationships even if they are in different areas.
Level-1-2 router
A router with both Level-1 and Level-2 router functions is a Level-1-2 router. It can establish Level-1 neighbor relationships with Level-1 and Level-1-2 routers in the same area. It can establish Level-2 neighbor relationships with Level-2 and Level-1-2 routers in different areas. A Level-1 router can reach other areas only through a Level-1-2 router. The Level-1-2 router maintains two LSDBs, a
Level-1 LSDB for intra-area routing and a Level-2 LSDB for inter-area routing.
IS-IS topology
Figure 41 shows one IS-IS network topology. Area 1 is the backbone that comprises a set of Level-2
routers. The other four areas are non-backbone areas connected to the backbone through Level-1-2 routers.
Figure 41 IS-IS topology 1
Area 3
Area 2
L1/L2
L1/L2
L1 L2
L2
L2
Area 1
L2
Area 5
L1/L2
Area 4
L1/L2 L1
L1
L1 L1
L1
162
Figure 42 shows another IS-IS topology. No area is defined as the backbone in this topology. The
backbone comprises all contiguous Level-2 and Level-1-2 routers in different areas. The IS-IS backbone does not need to be a specific area.
Figure 42 IS-IS topology 2
Area 1
L2
Area 2
L1
L1 L1/L2
L1/L2
Area 4
L1
Area 3
L2
Both the Level-1 and Level-2 routers use the SPF algorithm to generate the shortest path tree.
Route leaking
Level-2 and Level-1-2 routers form a Level-2 area. An IS-IS routing domain comprises only one
Level-2 area and multiple Level-1 areas. A Level-1 area must connect to the Level-1-2 area rather than another Level-1 area.
Level-1-2 routers send the routing information of Level-1 areas to the Level-2 area. Level-2 routers know the routing information of the entire IS-IS routing domain. By default, a Level-2 router does not advertise the routing information of other areas to a Level-1 area. A Level-1 router simply sends packets destined for other areas to the nearest Level-1-2 router. The path passing through the
Level-1-2 router might not be the best. To solve this problem, IS-IS provides the route leaking feature.
Route leaking enables a Level-1-2 router to advertise the routes of other areas to the connected
Level-1 area so that the Level-1 routers can select the optimal routes.
IS-IS network types
IS-IS supports broadcast networks (for example, Ethernet and Token Ring) and point-to-point networks (for example, PPP and HDLC).
IS-IS cannot run on P2MP links.
DIS and pseudonodes
IS-IS routers on a broadcast network must elect a DIS.
The Level-1 and Level-2 DISs are elected separately. You can assign different priorities to a router for different level DIS elections. The higher the router priority, the more likely the router becomes the
DIS. If multiple routers with the same highest DIS priority exist, the one with the highest Subnetwork
Point of Attachment (SNPA) address will be elected. On a broadcast network, the SNPA address is the MAC address. A router can be the DIS for different levels.
IS-IS DIS election differs from OSPF DIS election in the following ways:
•
A router with priority 0 can also participate in the DIS election.
163
•
When a router with a higher priority is added to the network, an LSP flooding process is performed to elect the router as the new DIS.
As shown in Figure 43 , the same level routers on a network, including non-DIS routers, establish
adjacency with each other.
Figure 43 DIS in the IS-IS broadcast network
L1/L2 L1/L2
L2 adjacencies
L1 adjacencies
L1
DIS
L2
DIS
The DIS creates and updates pseudonodes, and generates LSPs for the pseudonodes, to describe all routers on the network.
A pseudonode represents a virtual node on the broadcast network. It is not a real router. In IS-IS, it is identified by the system ID of the DIS and a 1-byte Circuit ID (a non-zero value).
Using pseudonodes simplifies network topology and can reduce the amount of resources consumed by SPF.
NOTE:
On an IS-IS broadcast network, all routers establish adjacency relationships, but they synchronize their LSDBs through the DIS.
IS-IS PDUs
PDU
IS-IS PDUs are encapsulated into link layer frames. An IS-IS PDU has two parts, the headers and the variable length fields. The headers comprise the PDU common header and the PDU specific header. All PDUs have the same PDU common header. The specific headers vary by PDU type.
Figure 44 PDU format
PDU common header PDU specific header Variable length fields (CLV)
Table 11 PDU types
17
18
20
24
Type
15
16
PDU Type
Level-1 LAN IS-IS hello PDU
Level-2 LAN IS-IS hello PDU
Point-to-Point IS-IS hello PDU
Level-1 Link State PDU
Level-2 Link State PDU
Level-1 Complete Sequence Numbers PDU
Acronym
L1 LAN IIH
L2 LAN IIH
P2P IIH
L1 LSP
L2 LSP
L1 CSNP
164
Type
25
26
PDU Type
Level-2 Complete Sequence Numbers PDU
Level-1 Partial Sequence Numbers PDU
Acronym
L2 CSNP
L1 PSNP
27 Level-2 Partial Sequence Numbers PDU L2 PSNP
Hello PDU
IS-to-IS hello (IIH) PDUs are used by routers to establish and maintain neighbor relationships. On broadcast networks, Level-1 routers use Level-1 LAN IIHs, and Level-2 routers use Level-2 LAN IIHs.
The P2P IIHs are used on point-to-point networks.
LSP
The LSPs carry link state information. LSPs include Level-1 LSPs and Level-2 LSPs. The Level-2
LSPs are sent by the Level-2 routers, and the Level-1 LSPs are sent by the Level-1 routers. The
Level-1-2 router can send both types of LSPs.
SNP
A sequence number PDU (SNP) describes the complete or partial LSPs for LSDB synchronization.
SNPs include CSNP and PSNP, which are further divided into Level-1 CSNP, Level-2 CSNP, Level-1
PSNP, and Level-2 PSNP.
A CSNP describes the summary of all LSPs for LSDB synchronization between neighboring routers.
On broadcast networks, CSNPs are sent by the DIS periodically (every 10 seconds by default). On point-to-point networks, CSNPs are sent only during the first adjacency establishment.
A PSNP only contains the sequence numbers of one or multiple latest received LSPs. It can acknowledge multiple LSPs at one time. When LSDBs are not synchronized, a PSNP is used to request missing LSPs from a neighbor.
CLV
The variable fields of PDU comprise multiple Code-Length-Value (CLV) triplets.
Figure 45 CLV format
Code
No. of Octets
1
Length 1
Value Length
Table 15 shows that different PDUs contain different CLVs. Codes 1 through 10 are defined in ISO
10589 (code 3 and 5 are not shown in the table). Codes 128 through 132 are defined in RFC 1195.
Table 12 CLV codes and PDU types
7
8
9
2
4
6
CLV Code
1
Name
Area Addresses
IS Neighbors (LSP)
Partition Designated Level 2 IS
IS Neighbors (MAC Address)
IS Neighbors (SNPA Address)
Padding
LSP Entries
PDU Type
IIH, LSP
LSP
L2 LSP
LAN IIH
LAN IIH
IIH
SNP
165
CLV Code
10
128
129
130
131
132
Name
Authentication Information
IP Internal Reachability Information
Protocols Supported
IP External Reachability Information
Inter-Domain Routing Protocol Information
IP Interface Address
PDU Type
IIH, LSP, SNP
LSP
IIH, LSP
L2 LSP
L2 LSP
IIH, LSP
IPv6 IS-IS
IS-IS supports multiple network protocols, including IPv6. To support IPv6, the IETF added two type-length-values (TLVs) and a new network layer protocol identifier (NLPID).
The TLVs are as follows:
•
IPv6 Reachability —Contains routing prefix and metric information to describe network reachability and has a type value of 236 (0xEC).
•
IPv6 Interface Address —Same as the "IP Interface Address" TLV in IPv4 ISIS, except that the
32-bit IPv4 address is translated to the 128-bit IPv6 address.
The new NLPID is an 8-bit field that identifies which network layer protocol is supported. For IPv6, the NLPID is 142 (0x8E).
Protocols and standards
•
ISO 8348, Ad2 Network Services Access Points
•
ISO 9542, ES-IS Routing Protocol
•
ISO 10589, ISO IS-IS Routing Protocol
•
RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
•
RFC 2973, IS-IS Mesh Groups
•
RFC 3277, IS-IS Transient Blackhole Avoidance
•
RFC 3358, Optional Checksums in ISIS
•
RFC 3359, Reserved Type, Length and Value (TLV) Codepoints in Intermediate System to
Intermediate System
•
RFC 3563, Cooperative Agreement Between the ISOC/IETF and ISO/IEC Joint Technical
Committee 1/Sub Committee 6 (JTC1/SC6) on IS-IS Routing Protocol Development
•
RFC 3719, Recommendations for Interoperable Networks using Intermediate System to
Intermediate System (IS-IS)
•
RFC 3787, Recommendations for Interoperable IP Networks using Intermediate System to
Intermediate System (IS-IS)
•
RFC 4444, Management Information Base for Intermediate System to Intermediate System
(IS-IS)
•
RFC 5029, Definition of an IS-IS Link Attribute Sub-TLV
•
RFC 5089, IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery
•
RFC 5130, A Policy Control Mechanism in IS-IS Using Administrative Tags
•
RFC 5301, Dynamic Hostname Exchange Mechanism for IS-IS
•
RFC 5302, Domain-Wide Prefix Distribution with Two-Level IS-IS
166
•
RFC 5303, Three-Way Handshake for IS-IS Point-to-Point Adjacencies
•
RFC 5304, IS-IS Cryptographic Authentication
•
RFC 5306, Restart Signaling for IS-IS
•
RFC 5308, Routing IPv6 with IS-IS
•
RFC 5310, IS-IS Generic Cryptographic Authentication
•
RFC 5311, Simplified Extension of Link State PDU (LSP) Space for IS-IS
•
RFC 6165, Extensions to IS-IS for Layer-2 Systems
•
RFC 6213, IS-IS BFD-Enabled TLV
•
RFC 6232, Purge Originator Identification TLV for IS-IS
•
RFC 6233, IS-IS Registry Extension for Purges
•
RFC 6329, IS-IS Extensions Supporting IEEE 802.1aq Shortest Path Bridging
•
RFC 6571, Loop-Free Alternate (LFA) Applicability in Service Provider (SP) Networks
•
RFC 6823, Advertising Generic Information in IS-IS
•
RFC 7142, OSI IS-IS Intra-domain Routing Protocol
•
RFC 7356, IS-IS Flooding Scope Link State PDUs (LSPs)
•
RFC 7370, Updates to the IS-IS TLV Codepoints Registry
•
RFC 7602, IS-IS Extended Sequence Number TLV
•
RFC 7645, The Keying and Authentication for Routing Protocol (KARP) IS-IS Security Analysis
•
RFC 7775, IS-IS Route Preference for Extended IP and IPv6 Reachability
•
RFC 7794, IS-IS Prefix Attributes for Extended IPv4 and IPv6 Reachability
•
RFC 7813, IS-IS Path Control and Reservation
•
RFC 7917, Advertising Node Administrative Tags in IS-IS
•
RFC 7981, IS-IS Extensions for Advertising Router Information
•
RFC 7987, IS-IS Minimum Remaining Lifetime
IPv4 IS-IS tasks at a glance
To configure IPv4 IS-IS, perform the following tasks:
1.
a.
b.
(Optional.) Setting the IS level and circuit level
c.
(Optional.) Configuring P2P network type for an interface
2.
(Optional.) Configuring IS-IS multi-instance processes
3.
(Optional.) Configuring IPv6 IS-IS MTR
4.
Configuring IS-IS route control
Enabling IS-IS to advertise the maximum link cost to neighbors
Specifying a preference for IS-IS
Configuring the maximum number of ECMP routes
Configuring IS-IS route summarization
Configuring IS-IS route redistribution
Filtering routes calculated from received LSPs
167
Filtering redistributed routes
Configuring IS-IS route leaking
Advertising IS-IS link state information to BGP
5.
(Optional.) Configuring IS-IS timers
Specifying the interval for sending IS-IS hello packets
Specifying the interval for sending IS-IS CSNP packets
Setting the maximum age of LSPs
Setting the LSP refresh interval and generation interval
Setting the LSP receiving interval
Setting the SPF calculation interval
6.
(Optional.) Configuring IS-IS packet-related features
Configuring a DIS priority for an interface
Configuring the tag value for an interface
Specifying the IS-IS hello multiplier
Disabling an interface from sending/receiving IS-IS packets
Enabling an interface to send small hello packets
Enabling LSP fragment extension
7.
(Optional.) Controlling LSP generation, advertisement and reception
Configuring IS-IS route update suppression
8.
(Optional.) Configuring advanced IS-IS features
Enabling source address check for hello packets on a P2P interface
Configuring convergence priorities for specific routes
Setting IS-IS interface cost upon LSDB overload
Configuring system ID to host name mappings
9.
(Optional.) Configuring IS-IS logging and SNMP notifications
Enabling the logging of neighbor state changes
Configuring IS-IS network management
10.
(Optional.) Configuring IS-IS fast convergence
11.
(Optional.) Enhancing IS-IS network security
Configuring neighbor relationship authentication
Configuring area authentication
Configuring routing domain authentication
12. (Optional.) Enhancing IS-IS network reliability
168
Controlling adjacency establishment and maintenance based on BFD session state
IPv6 IS-IS tasks at a glance
To configure IPv6 IS-IS, perform the following tasks:
1.
a.
b.
(Optional.) Setting the IS level and circuit level
c.
(Optional.) Configuring P2P network type for an interface
2.
(Optional.) Configuring IS-IS multi-instance processes
3.
4.
(Optional.) Configuring IS-IS route control
Enabling IS-IS to advertise the maximum link cost to neighbors
Specifying a preference for IS-IS
Configuring the maximum number of ECMP routes
Configuring IS-IS route summarization
Configuring IS-IS route redistribution
Filtering routes calculated from received LSPs
Filtering redistributed routes
Configuring IS-IS route leaking
Advertising IS-IS link state information to BGP
5.
(Optional.) Configuring IS-IS timers
Specifying the interval for sending IS-IS hello packets
Specifying the interval for sending IS-IS CSNP packets
Setting the maximum age of LSPs
Setting the LSP refresh interval and generation interval
Setting the LSP receiving interval
Setting the SPF calculation interval
6.
(Optional.) Configuring IS-IS packet-related features
Configuring a DIS priority for an interface
Configuring the tag value for an interface
Specifying the IS-IS hello multiplier
Disabling an interface from sending/receiving IS-IS packets
Enabling an interface to send small hello packets
Enabling LSP fragment extension
7.
(Optional.) Controlling LSP generation, advertisement and reception
169
Configuring IS-IS route update suppression
8.
(Optional.) Configuring advanced IS-IS features
Enabling source address check for hello packets on a P2P interface
Configuring convergence priorities for specific routes
Setting IS-IS interface cost upon LSDB overload
Configuring system ID to host name mappings
9.
(Optional.) Configuring IS-IS logging and SNMP notifications
Enabling the logging of neighbor state changes
Configuring IS-IS network management
10.
(Optional.) Configuring IS-IS fast convergence
11.
(Optional.) Enhancing IS-IS network security
Configuring neighbor relationship authentication
Configuring area authentication
Configuring routing domain authentication
12. (Optional.) Enhancing IS-IS network reliability
Controlling adjacency establishment and maintenance based on BFD session state
Configuring basic IS-IS
Enabling IPv4 IS-IS
1. Enter system view. system-view
2. Enable IS-IS and enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
By default, IS-IS is disabled.
3. Assign a NET. network-entity net
By default, NET is not assigned.
CAUTION:
If you want to execute the cost-style , is-level , and network-entity commands for the same IS-IS process, execute the network-entity command after the other two commands to avoid data loss.
4. Return to system view.
170
quit
5. Enter interface view. interface interface-type interface-number
6. Enable IS-IS on the interface. isis enable [ process-id ]
By default, IS-IS is disabled.
Enabling IPv6 IS-IS
1. Enter system view. system-view
2. Enable an IS-IS process and enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
By default, no IS-IS process is enabled.
3. Configure the NET for the IS-IS process. network-entity net
By default, the NET is not configured.
CAUTION:
If you want to execute the cost-style , is-level , and network-entity commands for the same IS-IS process, execute the network-entity command after the other two commands to avoid data loss.
4. Create the IPv6 address family and enter its view. address-family ipv6 [ unicast ]
5. Return to IS-IS view. quit
6. Return to system view. quit
7. Enter interface view. interface interface-type interface-number
8. Enable IPv6 for IS-IS on the interface. isis ipv6 enable [ process-id ]
By default, IPv6 is disabled for IS-IS on an interface.
Setting the IS level and circuit level
About this task
Follow these guidelines when you configure the IS level for routers in only one area:
•
Set the IS level of all routers to Level-1 or Level-2 rather than different levels because the routers do not need to maintain two identical LSDBs.
•
Set the IS level to Level-2 on all routers in an IP network for good scalability.
For an interface of a Level-1 or Level-2 router, the circuit level can only be Level-1 or Level-2. For an interface of a Level-1-2 router, the default circuit level is Level-1-2. If the router only needs to form
Level-1 or Level-2 neighbor relationships, set the circuit level for its interfaces to Level-1 or Level-2.
This will limit neighbor relationship establishment.
171
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the IS level. is-level { level-1 | level-1-2 | level-2 }
By default, the IS level is Level-1-2.
4. Return to system view. quit
5. Enter interface view. interface interface-type interface-number
6. Specify the circuit level. isis circuit-level [ level-1 | level-1-2 | level-2 ]
By default, an interface can establish either the Level-1 or Level-2 adjacency.
Configuring P2P network type for an interface
About this task
Interfaces with different network types operate differently. For example, broadcast interfaces on a network must elect the DIS and flood CSNP packets to synchronize the LSDBs. However, P2P interfaces on a network do not need to elect the DIS, and have a different LSDB synchronization mechanism.
If only two routers exist on a broadcast network, set the network type of attached interfaces to P2P.
This avoids DIS election and CSNP flooding, saving network bandwidth and speeding up network convergence.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure P2P network type for an interface. isis [ process-id process-id ] circuit-type p2p
By default, the network type of an interface varies by physical media. The network type of a
VLAN interface is broadcast.
Perform this task only for a broadcast network that has up to two attached routers.
Configuring IS-IS multi-instance processes
About this task
NOTE:
IS-IS processes not enabled with the multi-instance process feature are called traditional IS-IS processes. IS-IS processes enabled with the multi-instance process feature are called IS-IS multi-instance processes.
172
By default, an interface supports only one IS-IS process. To configure multiple IS-IS processes on a device, you must add more interfaces to the device and configure the interfaces manually. To simplify configuration, use the IS-IS multi-instance process feature to configure multiple IS-IS multi-instance processes as well as a traditional IS-IS process on an interface.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable the IS-IS multi-instance process and specify an instance ID for the process.
multi-instance enable iid iid-value
By default, IS-IS multi-instance process is disabled.
4. Configure IS-IS multi-instance processes on an interface: a. Return to system view. quit b. Enter interface view. interface interface-type interface-number c. Enable an IS-IS multi-instance process on the interface:
IPv4: isis enable [ process-id ]
By default, IPv4 IS-IS is disabled on an interface, and the interface is not enabled with any
IS-IS processes.
IPv6: isis ipv6 enable [ process-id ]
By default, IPv6 IS-IS is disabled on an interface, and the interface is not enabled with any
IS-IS processes.
Configuring IPv6 IS-IS MTR
About this task
On a network, IPv4 and IPv6 topologies must be consistent so that both IPv6 IS-IS and IPv4 IS-IS can use the SPF algorithm to perform route calculation. If they are different, routers supporting both
IPv4 and IPv6 might send IPv6 packets to routers that do not support IPv6, resulting in packet loss.
To resolve this issue, configure IPv6 IS-IS MTR to perform route calculation separately in IPv4 and
IPv6 topologies.
173
Figure 46 Network diagram
Router A
IPv6 IPv6
Router B
4
IPv6 IPv4
36 3
IPv6 IPv4
5
Router D
IPv4 IPv4
Router C
both IPv4 and IPv6. Router C supports only IPv4 and cannot forward IPv6 packets.
Enable IPv6 IS-IS MTR on Router A, Router B, Router C, and Router D to make them perform route calculation separately in IPv4 and IPv6 topologies. With this configuration, Router A does not forward
IPv6 packets destined to Router D through Router B, avoiding packet loss.
Restrictions and guidelines
As a best practice to avoid route calculation failures, configure this feature when both IPv4 and IPv6 topologies exist in the network.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify an IS-IS cost style. cost-style { compatible | wide | wide-compatible }
By default, IS-IS only transmits and receives packets using the narrow cost style.
4. Enter IPv6 address family view. address-family ipv6 [ unicast ]
5. Enable IPv6 IS-IS MTR. multi-topology [ compatible ]
By default, IPv6 IS-IS MTR is disabled.
Configuring IS-IS route control
Configuring IS-IS link cost
About this task
The IS-IS cost of an interface is determined in the following order:
1. IS-IS cost specified in interface view.
2. IS-IS cost specified in system view.
The cost is applied to the interfaces associated with the IS-IS process.
3. Automatically calculated cost.
174
If the cost style is wide or wide-compatible , IS-IS automatically calculates the cost using the formula: Interface cost = (Bandwidth reference value / Expected interface bandwidth) × 10,
in the range of 1 to 16777214. For other cost styles, Table 16 applies.
Configure the expected bandwidth of an interface with the bandwidth command.
Table 13 Automatic cost calculation scheme for cost styles other than wide and wide-compatible
Interface bandwidth
≤ 10 Mbps
≤ 100 Mbps
≤ 155 Mbps
≤ 622 Mbps
≤ 2500 Mbps
Interface cost
60
50
40
30
20
> 2500 Mbps 10
4. If none of the above costs is used, a default cost of 10 applies.
Configuring an IPv4 IS-IS cost for an interface
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. (Optional.) Specify an IS-IS cost style. cost-style { narrow | wide | wide-compatible | { compatible | narrow-compatible } [ relax-spf-limit ] }
By default, the IS-IS cost type is narrow .
4. Return to system view. quit
5. Enter interface view. interface interface-type interface-number
6. Specify a cost for the IS-IS interface. isis [ process-id process-id ] cost cost value [ level-1 | level-2 ]
By default, no cost for the interface is specified.
Configuring a global IPv4 IS-IS cost
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify a global IS-IS cost. circuit-cost cost-value [ level-1 | level-2 ]
By default, no global cost is specified.
Enabling automatic IPv4 IS-IS cost calculation
1. Enter system view. system-view
175
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable automatic IS-IS cost calculation. auto-cost enable
By default, automatic IS-IS cost calculation is disabled.
4. (Optional.) Configure a bandwidth reference value for automatic IS-IS cost calculation. bandwidth-reference value
The default setting is 100 Mbps.
Configuring an IPv6 IS-IS cost for an interface
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. (Optional.) Specify an IS-IS cost style. cost-style { narrow | wide | wide-compatible | { compatible | narrow-compatible } [ relax-spf-limit ] }
By default, the IS-IS cost type is narrow .
4. Enter IPv6 address family view. address-family ipv6 [ unicast ]
5. Return to IS-IS view. quit
6. Return to system view. quit
7. Enter interface view. interface interface-type interface-number
8. Enable IPv6 for IS-IS on the interface. isis ipv6 enable [ process-id ]
By default, IPv6 is disabled for IS-IS on an interface.
9. Specify an IPv6 cost for the IS-IS interface. isis [ process-id process-id ] ipv6 cost cost-value [ level-1 | level-2 ]
By default, no IPv6 cost is specified for the interface.
Configuring a global IPv6 IS-IS cost
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IPv6 address family view. address-family ipv6 [ unicast ]
4. Specify a global IPv6 IS-IS cost.
circuit-cost cost-value [ level-1 | level-2 ]
By default, no global IPv6 cost is specified.
176
Enabling automatic IPv6 IS-IS cost calculation
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. (Optional.) Specify an IS-IS cost style. cost-style { narrow | wide | wide-compatible | { compatible | narrow-compatible } [ relax-spf-limit ] }
4. Enter IPv6 address family view. address-family ipv6 [ unicast ]
5. Enable automatic IPv6 IS-IS cost calculation. auto-cost enable
By default, automatic IPv6 IS-IS cost calculation is disabled.
6. (Optional.) Configure a bandwidth reference value for automatic IPv6 IS-IS cost calculation. bandwidth-reference value
By default, the bandwidth reference value is 100 Mbps.
Enabling IS-IS to advertise the maximum link cost to neighbors
About this task
On an IS-IS network, when a link recovers from failures or the state of an interface changes, IS-IS will re-establish neighbor relationships and perform route convergence. During the route convergence process, routing loops and traffic loss might occur because the convergence speeds of the nodes are different. To address this issue, enable IS-IS to advertise the maximum link cost to neighbors within a specific period, so the traffic forwarding path remains unchanged. After the specified period, IS-IS advertises the original link cost to neighbors and performs optimal route selection again.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IS-IS to advertise the maximum link cost to neighbors within the specified period. isis peer hold-max-cost duration time
By default, IS-IS does not advertise the maximum link cost to neighbors.
Specifying a preference for IS-IS
About this task
If multiple routing protocols find routes to the same destination, the route found by the routing protocol that has the highest preference is selected as the optimal route.
Perform this task to assign a preference to IS-IS directly or by using a routing policy. For more
information about the routing policy, see " Configuring routing policies ."
177
Configuring a preference for IPv4 IS-IS
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Configure a preference for IPv4 IS-IS. preference { preference | route-policy route-policy-name } *
The default setting is 15.
Configuring a preference for IPv6 IS-IS
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Configure a preference for IPv6 IS-IS. preference { preference | route-policy route-policy-name } *
The default setting is 15.
Configuring the maximum number of ECMP routes
About this task
Perform this task to implement load sharing over ECMP routes in order to improve link utilization.
Configuring the maximum number of ECMP routes for IPv4 IS-IS
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Specify the maximum number of ECMP routes.
maximum load-balancing number
By default, the maximum number of IPv4 IS-IS ECMP routes equals the maximum number of
ECMP routes, which is configurable by using the max-ecmp-num command.
Configuring the maximum number of ECMP routes for IPv6 IS-IS
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Specify the maximum number of ECMP routes.
maximum load-balancing number
178
By default, the maximum number of IPv6 IS-IS ECMP routes equals the maximum number of
ECMP routes, which is configurable by using the max-ecmp-num command.
Configuring IS-IS route summarization
About this task
Perform this task to summarize specific routes, including IS-IS routes and redistributed routes, into a single route. Route summarization can reduce the routing table size and the LSDB scale.
Route summarization applies only to locally generated LSPs.
Configuring IPv4 IS-IS route summarization
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Configure IPv4 IS-IS route summarization. summary ip-address { mask-length | mask } [ avoid-feedback | generate_null0_route | [ level-1 | level-1-2 | level-2 ] | tag tag ] *
By default, IPv4 IS-IS route summarization is not configured.
The cost of the summary route is the lowest one among the costs of the more-specific routes.
Configuring IPv6 IS-IS route summarization
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Configure IPv6 IS-IS route summarization.
summary ipv6-prefix prefix-length [ avoid-feedback | generate_null0_route | [ level-1 | level-1-2 | level-2 ] | tag tag ]
*
By default, IPv6 IS-IS route summarization is not configured.
Advertising a default route
About this task
IS-IS cannot redistribute a default route to its neighbors. This task enables IS-IS to advertise a default route of 0.0.0.0/0 in an LSP to the same-level neighbors. Upon receiving the default route, the neighbors add it into their routing table.
Advertising an IPv4 IS-IS default route
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
179
address-family ipv4 [ unicast ]
3. Advertise a Level-1 or Level-2 default route. default-route-advertise [ avoid-learning | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
By default, IPv4 IS-IS does not advertise a Level-1 or Level-2 default route.
Advertising an IPv6 IS-IS default route
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Advertise a Level-1 or Level-2 default route. default-route-advertise [ avoid-learning | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
By default, IPv6 IS-IS does not advertise a Level-1 or Level-2 default route.
Configuring IS-IS route redistribution
About this task
Perform this task to redistribute routes from other routing protocols into IS-IS. You can specify a cost for redistributed routes and specify the maximum number of redistributed routes.
Configuring IPv4 IS-IS route redistribution
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Redistribute routes from other routing protocols or other IS-IS processes. import-route bgp [ as-number ] [ allow-ibgp ] [ cost cost-value | cost-type { external | internal } | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] * import-route { direct | static } [ cost cost-value | cost-type { external
| internal } | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
import-route { isis | ospf | rip } [ process-id | all-processes ]
[ allow-direct | cost cost-value | cost-type { external | internal } |
[ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
By default, IS-IS does not redistribute routes.
This command redistributes only active routes. To display active routes, use the display ip routing-table protocol command.
4. (Optional.) Configure the maximum number of redistributed Level 1/Level 2 IPv4 routes.
import-route limit number
By default, the maximum number of redistributed Level 1/Level 2 IPv4 routes is 1835008.
180
Configuring IPv6 IS-IS route redistribution
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Redistribute routes from other routing protocols or other IS-IS processes.
import-route protocol [ as-number | process-id ] [ allow-ibgp ]
[ allow-direct | cost cost-value ] | [ level-1 | level-1-2 | level-2 ] |
route-policy route-policy-name | tag tag ] *
By default, IPv6 IS-IS does not redistribute routes.
5. (Optional.) Configure the maximum number of redistributed Level 1/Level 2 IPv6 routes.
import-route limit number
By default, the maximum number of redistributed Level 1/Level 2 IPv6 routes is 917504.
Filtering routes calculated from received LSPs
About this task
IS-IS saves LSPs received from neighbors in the LSDB, and uses the SPF algorithm to calculate the shortest path tree with itself as the root. IS-IS installs the calculated routes to the IS-IS routing table and the optimal routes to the IP routing table.
Perform this task to filter calculated routes. Only routes that are not filtered can be added to the IP routing table. The filtered routes retain in the IS-IS routing table and can be advertised to neighbors.
Filtering IPv4 IS-IS routes calculated from received LSPs
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Filter routes calculated using received LSPs. filter-policy { ipv4-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } import
By default, IPv4 IS-IS route filtering is not configured.
Filtering IPv6 IS-IS routes calculated from received LSPs
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Filter routes calculated using received LSPs. filter-policy { ipv6-acl-number | prefix-list prefix-list-name |
route-policy route-policy-name } import
181
By default, IPv6 IS-IS route filtering is not configured.
Filtering redistributed routes
About this task
IS-IS can redistribute routes from other routing protocols or other IS-IS processes, add them to the
IS-IS routing table, and advertise them in LSPs.
Perform this task to filter redistributed routes. Only routes that are not filtered can be added to the
IS-IS routing table and advertised to neighbors.
Restrictions and guidelines
Use this command together with the import-route command.
Filtering redistributed IPv4 IS-IS routes
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Filter routes redistributed from other routing protocols or IS-IS processes. filter-policy { ipv4-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } export [ bgp | direct | { isis | ospf | rip } [ process-id ] | static ]
By default, IPv4 IS-IS route filtering is not configured.
Filtering redistributed IPv6 IS-IS routes
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Filter routes redistributed from other routing protocols or IS-IS processes. filter-policy { ipv6-acl-number | prefix-list prefix-list-name |
route-policy route-policy-name } export [ protocol [ process-id ] ]
By default, IPv6 IS-IS route filtering is not configured.
Configuring IS-IS route leaking
About this task
Perform this task to control route advertisement (route leaking) between Level-1 and Level-2.
You can configure IS-IS to advertise routes from Level-2 to Level-1, and to not advertise routes from
Level-1 to Level-2.
Configuring IPv4 IS-IS route leaking
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view.
182
isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Configure route leaking from Level-1 to Level-2. import-route isis level-1 into level-2 [ filter-policy
{ ipv4-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
By default, IS-IS advertises routes from Level-1 to Level-2.
4. Configure route leaking from Level-2 to Level-1. import-route isis level-2 into level-1 [ filter-policy
{ ipv4-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
By default, IS-IS does not advertise routes from Level-2 to Level-1.
Configuring IPv6 IS-IS route leaking
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Configure route leaking from Level-2 to Level-1. import-route isisv6 level-2 into level-1 [ filter-policy
{ ipv6-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
By default, IS-IS does not advertise routes from Level-2 to Level-1.
5. Configure route leaking from Level-1 to Level-2. import-route isisv6 level-1 into level-2 [ filter-policy
{ ipv6-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
By default, IS-IS advertises routes from Level-1 to Level-2.
Advertising IS-IS link state information to BGP
About this task
After the device advertises IS-IS link state information to BGP, BGP can advertise the information for intended applications. For more information about BGP LS, see "Configuring BGP LS."
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Advertise IS-IS link state information to BGP. distribute bgp-ls [ instance-id id ] [ level-1 | level-2 ]
By default, the device does not advertise IS-IS link state information to BGP.
183
Configuring IS-IS timers
Specifying the interval for sending IS-IS hello packets
About this task
If a neighbor does not receive any hello packets from the router within the advertised hold time, it considers the router down and recalculates the routes. The hold time is the hello multiplier multiplied by the hello interval.
Restrictions and guidelines
The interval between hello packets sent by the DIS is 1/3 the hello interval set with the isis timer hello command.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify the interval for sending hello packets.
isis timer hello seconds [ level-1 | level-2 ]
The default setting is 10 seconds.
Specifying the interval for sending IS-IS CSNP packets
About this task
On a broadcast network, perform this task on the DIS that uses CSNP packets to synchronize
LSDBs.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify the interval for sending CSNP packets on the DIS of a broadcast network.
isis timer csnp seconds [ level-1 | level-2 ]
The default setting is 10 seconds.
Setting the maximum age of LSPs
About this task
Each LSP has an age that decreases in the LSDB. Any LSP with an age of 0 is deleted from the
LSDB. You can adjust the age value based on the scale of a network.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view.
184
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the maximum LSP age.
timer lsp-max-age seconds
The default setting is 1200 seconds.
Setting the LSP refresh interval and generation interval
About this task
Each router needs to refresh its LSPs at a configurable interval and send them to other routers to prevent valid routes from aging out. A smaller refresh interval speeds up network convergence but consumes more bandwidth.
When network topology changes such as neighbor state, interface metric, system ID, or area ID changes occur, the router generates an LSP after a configurable interval. If such a change occurs frequently, excessive LSPs are generated, consuming a large amount of router resources and bandwidth. To solve the problem, you can adjust the LSP generation interval.
Restrictions and guidelines
Follow these restrictions and guidelines when you configure the timer lsp-generation command:
•
If you specify only the maximum-interval argument, the LSP generation interval is maximum-interval .
•
If you do not specify the incremental-interval argument, the LSP generation interval is in the range of minimum-interval to maximum-interval .
•
If you specify the incremental-interval argument, the LSP generation interval is as follows:
When network changes are not frequent, the minimum-interval is adopted.
When network changes are frequent, the LSP generation interval increases by incremental-interval × 2 n-2
(n is the number of calculation times) each time a generation occurs until the maximum-interval is reached.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the LSP refresh interval.
timer lsp-refresh seconds
By default, the LSP refresh interval is 900 seconds.
4. Set the LSP generation interval.
timer lsp-generation maximum-interval [ minimum-interval
[ incremental-interval ] ] [ level-1 | level-2 ]
By default:
The maximum interval is 5 seconds.
The minimum interval is 50 milliseconds.
The incremental interval is 200 milliseconds.
185
Setting LSP sending intervals
About this task
If a change occurs in the LSDB, IS-IS advertises the changed LSP to neighbors. You can specify the minimum interval for sending these LSPs to control the amount of LSPs on the network.
On a P2P link, IS-IS requires an advertised LSP be acknowledged. If no acknowledgment is received within a configurable interval, IS-IS will retransmit the LSP.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify the minimum interval for sending LSPs and the maximum LSP number that can be sent at a time.
isis timer lsp time [ count count ]
By default, the minimum interval is 33 milliseconds, and the maximum LSP number that can be sent at a time is 5.
4. Specify the LSP retransmission interval on a P2P link.
isis timer retransmit seconds
By default, the LSP retransmission interval on a P2P link is 5 seconds.
Setting the LSP receiving interval
About this task
When the network is stable, IS-IS uses the minimum receiving interval. When the network changes frequently, the receiving interval increases by the incremental interval each time the same LSP is received until the maximum receiving interval is reached.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the LSP receiving interval.
timer lsp-arrival maximum-interval [ minimum-interval
[ incremental-interval ] ] [ level-1 | level-2 ]
By default, the LSP receiving interval is not set.
Setting the SPF calculation interval
About this task
Based on the LSDB, an IS-IS router uses the SPF algorithm to calculate the shortest path tree with itself being the root, and uses the shortest path tree to determine the next hop to a destination network. By adjusting the SPF calculation interval, you can prevent bandwidth and router resources from being over consumed due to frequent topology changes.
186
When network changes are not frequent, the minimum-interval is adopted. If network changes become frequent, the SPF calculation interval increases by incremental-interval × 2 n-2
(n is the number of calculation times) each time a calculation occurs until the maximum-interval is reached.
Setting the IPv4 SPF calculation interval
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the SPF calculation interval. timer spf { maximum-interval [ minimum-interval [ incremental-interval
[ conservative ] ] ] | millisecond millisecond-interval }
[ exclude-prc ]
By default:
The maximum interval is 5 seconds.
The minimum interval is 50 milliseconds.
The incremental interval is 200 milliseconds.
Setting the IPv6 SPF calculation interval
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IPv6 address family view. address-family ipv6 [ unicast ]
4. Set the SPF calculation interval. timer spf { maximum-interval [ minimum-interval [ incremental-interval
[ conservative ] ] ] | millisecond millisecond-interval }
[ exclude-prc ]
By default:
The maximum interval is 5 seconds.
The minimum interval is 50 milliseconds.
The incremental interval is 200 milliseconds.
Configuring IS-IS packet-related features
Configuring a DIS priority for an interface
About this task
On a broadcast network, IS-IS must elect a router as the DIS at a routing level. You can specify a DIS priority at a level for an interface. The greater the interface's priority, the more likely it becomes the
DIS. If multiple routers in the broadcast network have the same highest DIS priority, the router with the highest MAC address becomes the DIS.
Procedure
1. Enter system view. system-view
187
2. Enter interface view. interface interface-type interface-number
3. Configure a DIS priority for the interface.
isis dis-priority priority [ level-1 | level-2 ]
The default setting is 64.
Configuring the tag value for an interface
About this task
Perform this task when the link cost style is wide , wide-compatible , or compatible .
When IS-IS advertises a prefix with a tag value, IS-IS adds the tag to the IP reachability information
TLV of the prefix.
Configuring the IPv4 IS-IS tag value for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the IPv4 IS-IS tag value for the interface.
isis tag tag
By default, the IPv4 IS-IS tag value of the interface is not configured.
Configuring the IPv6 IS-IS tag value for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure the IPv6 IS-IS tag value for the interface.
isis ipv6 tag tag
By default, the IPv6 IS-IS tag value of the interface is not configured.
When IS-IS advertises an IPv6 prefix with a tag value, it adds the tag to the IPv6 reachability information TLV, regardless of the link cost style.
Specifying the IS-IS hello multiplier
About this task
The hello multiplier is the number of hello packets a neighbor must miss before it declares that the router is down.
If a neighbor receives no hello packets from the router within the advertised hold time, it considers the router down and recalculates the routes. The hold time is the hello multiplier multiplied by the hello interval.
On a broadcast link, Level-1 and Level-2 hello packets are advertised separately. You must set a hello multiplier for each level.
On a P2P link, Level-1 and Level-2 hello packets are advertised in P2P hello packets. You do not need to specify Level-1 or Level-2.
188
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify the hello multiplier. isis timer holding-multiplier value [ level-1 | level-2 ]
The default setting is 3.
Disabling an interface from sending/receiving IS-IS packets
About this task
After being disabled from sending and receiving hello packets, an interface cannot form any neighbor relationship, but can advertise directly connected networks in LSPs through other interfaces. This can save bandwidth and CPU resources, and ensures that other routers know networks directly connected to the interface.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Disable the interface from sending and receiving IS-IS packets. isis silent
By default, the interface can send and receive IS-IS packets.
Enabling an interface to send small hello packets
About this task
IS-IS messages cannot be fragmented at the IP layer because they are directly encapsulated in frames. Any two IS-IS neighboring routers must negotiate a common MTU. To avoid sending big hellos to save bandwidth, enable the interface to send small hello packets without CLVs.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable the interface to send small hello packets without CLVs. isis small-hello
By default, the interface sends standard hello packets.
Setting LSP lengths
About this task
IS-IS messages cannot be fragmented at the IP layer because they are directly encapsulated in frames. IS-IS routers in an area must send LSPs smaller than the smallest interface MTU in the area.
189
If the IS-IS routers have different interface MTUs, configure the maximum size of generated LSP packets to be smaller than the smallest interface MTU in the area. Without the configuration, the routers must dynamically adjust the LSP packet size to fit the smallest interface MTU, which takes time and affects other services.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the maximum length of generated Level-1 LSPs or Level-2 LSPs.
lsp-length originate size [ level-1 | level-2 ]
By default, the maximum length of generated Level-1 LSPs or Level-2 LSPs is 1497 bytes.
4. Specify the maximum length of received LSPs.
lsp-length receive size
By default, the maximum length of received LSPs is 1497 bytes.
Enabling LSP flash flooding
About this task
Changed LSPs can trigger SPF recalculation. To advertise the changed LSPs before the router recalculates routes for faster network convergence, enable LSP flash flooding.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable LSP flash flooding. flash-flood [ flood-count flooding-count | max-timer-interval flooding-interval | [ level-1 | level-2 ] ] *
By default, LSP flash flooding is disabled.
Enabling LSP fragment extension
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable LSP fragment extension. lsp-fragments-extend [ level-1 | level-1-2 | level-2 ]
By default, LSP fragment extension is disabled.
The MTUs of all interfaces running the IS-IS process must not be less than 512. Otherwise, LSP fragment extension does not take effect.
4. Configure a virtual system ID. virtual-system virtual-system-id
By default, no virtual system ID is configured.
190
Configure a minimum of one virtual system to generate extended LSP fragments.
Controlling LSP generation, advertisement and reception
Limiting LSP flooding
About this task
In NBMA networks such as ATM and FR, many P2P links exist. As shown in Figure 47 , Routers A, B,
C and D run IS-IS. When Router A generates an LSP, it floods the LSP out of HGE1/0/1, HGE1/0/2, and HGE1/0/3. After Router D receives the LSP from HGE1/0/3, it floods it out of HGE1/0/1 and
HGE1/0/2 to Router B and Router C. However, Router B and Router C have already received the
LSP from Router A. Repeated LSP flooding consumes extra bandwidth.
Figure 47 Network diagram of a fully meshed network
Router D Router A
HGE1/0/1
HGE1/0/2
HGE1/0/3
HGE1/0/3
HGE1/0/2
HGE1/0/1
HGE1/0/1
HGE1/0/1
HGE1/0/2
HGE1/0/3
HGE1/0/2
HGE1/0/3
Router B Router C
To avoid this problem, you can add interfaces to a mesh group or block some interfaces.
•
An interface in a mesh group floods a received LSP only to interfaces not in the mesh group.
•
A blocked interface sends LSPs only after receiving LSP requests.
Restrictions and guidelines
Before you configure this task, you must consider redundancy for interfaces in case LSP packets cannot be flooded because of link failures.
Procedure
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Limit LSP flooding.
Add the interface to a mesh group.
isis mesh-group mesh-group-number
Block the interface. isis mesh-group mesh-blocked
By default, the interface does not belong to any mesh group and is not blocked.
The commands take effect only on P2P interfaces.
191
Configuring IS-IS route update suppression
About this task
Perform this task to protect network resources and routers from being overwhelmed by LSPs when route flapping occurs.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure IS-IS route update suppression.
Suppress LSP generation.
timer lsp-generation suppress-flapping delay-interval [ threshold threshold-value ] [ level-1 | level-2 ]
By default, IS-IS does not suppress LSP generation.
Suppress LSP flooding.
timer lsp-flood suppress-flapping delay-interval [ threshold threshold-value ] [ level-1 | level-2 ]
By default, IS-IS does not suppress LSP flooding.
Suppress route calculation.
timer route-calculate suppress-flapping delay-interval
[ threshold threshold-value ] [ level-1 | level-2 ]
By default, IS-IS does not suppress route calculation.
Suppress route calculation after fragment 0 of a purge LSP is received.
timer purge-zero-lsp route-calculate-delay delay-interval
[ level-1 | level-2 ]
By default, IS-IS suppresses route calculation for 10 seconds after fragment 0 of a purge
LSP is received.
Configuring advanced IS-IS features
Enabling source address check for hello packets on a P2P interface
About this task
An IS-IS P2P interface can have a peer on a different network. Perform this task to configure an IS-IS
P2P interface to establish neighbor relationship only with a peer on the same network.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable source address check for hello packets on a P2P interface. isis peer-ip-check
192
By default, an IS-IS P2P interface can have a peer on a different network.
The command applies only to P2P interfaces.
Configuring convergence priorities for specific routes
About this task
A topology change causes IS-IS routing convergence. To improve convergence speed, you can assign convergence priorities to IS-IS routes. Convergence priority levels are critical, high, medium, and low. The higher the convergence priority, the faster the convergence speed.
By default, IS-IS host routes have medium convergence priority, and other IS-IS routes have low convergence priority.
Configuring convergence priorities for specific IPv4 IS-IS routes
1. Enter system view. system-view
2. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
3. Assign convergence priorities to specific IPv4 IS-IS routes.
Assign a convergence priority to IPv4 IS-IS routes matching the specified prefix list. prefix-priority { critical | high | medium } { prefix-list prefix-list-name | tag tag-value }
Assign a convergence priority to IPv4 IS-IS routes by using a route policy.
prefix-priority route-policy route-policy-name
By default, IPv4 IS-IS routes, except IS-IS host routes, have the low convergence priority.
Configuring convergence priorities for specific IPv6 IS-IS routes
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IPv6 address family view. address-family ipv6 [ unicast ]
4. Assign convergence priorities to specific IPv6 IS-IS routes. prefix-priority { critical | high | medium } { prefix-list prefix-list-name | tag tag-value } prefix-priority route-policy route-policy-name
By default, IPv6 IS-IS routes, except IS-IS host routes, have the low convergence priority.
Setting the LSDB overload bit
About this task
By setting the overload bit in sent LSPs, a router informs other routers of failures that make it unable to select routes and forward packets.
When an IS-IS router cannot record the complete LSDB, for example, because of memory insufficiency, it will calculate wrong routes. To make troubleshooting easier, temporarily isolate the router from the IS-IS network by setting the overload bit.
193
Restrictions and guidelines
When you set the LSDB overload bit in IS-IS view, the OL bit is set for LSPs flooded to IPv4 and IPv6 topologies.
When you set the LSDB overload bit in IPv6 address family view, the configuration does not take effect.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view or IPv6 address family view.
Enter IS-IS view: isis [ process-id ] [ vpn-instance vpn-instance-name ]
Execute the following commands in sequence to enter IPv6 address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv6 [ unicast ]
3. Set the overload bit. set-overload [ on-startup [ [ start-from-nbr system-id [ timeout1
[ nbr-timeout ] ] ] | timeout2 | wait-for-bgp [ timeout3 ] ] ] [ allow
{ external | interlevel } * ]
By default, the overload bit is not set.
Setting IS-IS interface cost upon LSDB overload
About this task
Perform this task to prevent neighbor devices from sending traffic to an overloaded device in an anycast scenario.
Upon entering the overload state, the device sends an LSP with the OL bit set to its neighbors. The neighbor that receives the LSP performs path calculation and forwards packets as follows:
•
For packets destined to a network not directly connected to the overloaded device, the neighbor device does not forward the packets to the overloaded device.
•
For packets destined to the network directly connected to the overloaded device, the neighbor device forwards the packets to the overloaded device.
These processing methods might cause problems in an anycast scenario where the destination address of packets is an anycast address. The neighbor device will send such packets to the anycast node with the smallest cost, and that node might have already entered the overload state. To avoid such problems, perform this task to enable an overloaded device to increase its cost. Neighbors will not select the device during path calculation.
The command takes effect when the device enters the overload state as follows:
•
When the device is in overload state, the system increases the cost of all IS-IS interfaces on the device. Neighbors will not select the device during path calculation.
•
When the device exits the overload state or you execute the undo overload adjust-cost command, the IS-IS interfaces resume their original costs.
Restrictions and guidelines
When you set IS-IS interface cost upon LSDB overload, the configuration takes effect as follows:
•
The configuration in IS-IS view applies to both IPv4 and IPv6 IS-IS interfaces.
•
The configuration in IPv6 address family view does not take effect.
194
Procedure
1. Enter system view. system-view
2. Enter IS-IS view or IPv6 address family view.
Enter IS-IS view: isis [ process-id ] [ vpn-instance vpn-instance-name ]
Execute the following commands in sequence to enter IPv6 address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv6 [ unicast ]
3. Set the cost for all IS-IS interfaces when the device enters the overload state. overload adjust-cost { cost-offset | max }
By default, the device does not change the cost for any IS-IS interfaces when it enters the overload state.
Configuring the ATT bit
About this task
The ATT bit is used to identify the connection status between a Level-1 area and other areas. By default, a Level-1-2 router sets the ATT bit for Level-1 LSPs as follows:
•
The Level-1-2 router sets the ATT bit in Level-1 LSPs to inform the Level-1 devices that it can reach other areas. After a Level-1 device receives a Level-1 LSP with the ATT bit set, it generates a default route destined for the Level-1-2 router.
•
The Level-1-2 router does not set the ATT bit in Level-1 LSPs if it can reach only one area.
To edit the default ATT bit setting rule for a Level-1-2 router, perform the following tasks as needed:
•
To enable ATT bit setting for all Level-1 LSPs, execute the set-att always command on the
Level-1-2 router.
•
To disable a Level-1 device from generating a default route upon receiving an ATT-bit-set
Level-1 LSP from the Level-1-2 router, you can perform one of the following tasks:
Execute the ignore-att command on the Level-1 device.
Execute the set-att never command on the Level-1-2 router.
Configuring IS-IS not to calculate the default route through the ATT bit
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure IS-IS not to calculate the default route through the ATT bit. ignore-att
By default, IS-IS uses the ATT bit to calculate the default route.
Setting the ATT bit of IPv4 Level-1 LSPs
1. Enter system view. system-view
2. Enter IS-IS view isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the ATT bit of IPv4 Level-1 LSPs.
195
set-att { always | never }
By default, the Level-1-2 router sets the ATT bit for IPv4 Level-1 LSPs in accordance with the default ATT bit setting rule.
Setting the IPv6 ATT bit of Level-1 LSPs
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IPv6 address family view. address-family ipv6 [ unicast ]
4. Set the IPv6 ATT bit of Level-1 LSPs. set-att { always | never }
By default, the Level-1-2 router sets the ATT bit for IPv6 Level-1 LSPs in accordance with the default ATT bit setting rule.
Configuring system ID to host name mappings
About this task
A 6-byte system ID in hexadecimal notation uniquely identifies a router or host in an IS-IS network.
To make a system ID easy to read, the system allows you to use host names to identify devices. It also provides mappings between system IDs and host names.
The mappings can be configured manually or dynamically.
•
Static system ID to host name mapping —You must manually configure a mapping for each router in the network. When a new router is added to the network or a mapping must be modified, you must configure all routers manually.
•
Dynamic system ID to host name mapping —You only need to configure a host name for each router in the network. Each router advertises the host name in a dynamic host name CLV to other routers so all routers in the network can have all mappings. To help check the origin of
LSPs in the LSDB, you can configure a name for the DIS in a broadcast network.
Restrictions and guidelines
Follow these guidelines when you configure the mappings:
•
To view host names rather than system IDs by using the display isis lsdb command, you must enable dynamic system ID to host name mapping.
•
If you configure both dynamic mapping and static mapping on a router, the host name specified for dynamic mapping applies.
Configuring a static system ID to host name mapping
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure a system ID to host name mapping for a remote IS. is-name map sys-id map-sys-name
By default, no system ID to host name mapping is configured for a remote IS.
A system ID can correspond to only one host name.
196
Configuring dynamic system ID to host name mapping
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify a host name for the IS and enable dynamic system ID to host name mapping.
is-name sys-name
By default, dynamic system ID to host name mapping is disabled and no host name is specified for the router.
4. Return to system view. quit
5. Enter interface view. interface interface-type interface-number
6. Configure a DIS name.
isis dis-name symbolic-name
By default, no DIS name is configured.
This command takes effect only on a router enabled with dynamic system ID to host name mapping.
This command is not available on P2P interfaces.
Configuring IS-IS logging and SNMP notifications
Enabling the logging of neighbor state changes
About this task
With this feature enabled, the router delivers logs about neighbor state changes to its information center. The information center processes the logs according to user-defined output rules (whether to output logs and where to output). For more information about the information center, see information center configuration in System Management Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable the logging of neighbor state changes. log-peer-change
By default, the logging of neighbor state changes is enabled.
Configuring IS-IS network management
About this task
This task includes the following configurations:
•
Bind an IS-IS process to MIB so that you can use network management software to manage the specified IS-IS process.
197
•
Enable IS-IS notifications to report important events.
To report critical IS-IS events to an NMS, enable SNMP notifications for IS-IS. For SNMP notifications to be sent correctly, you must also configure SNMP on the device. For more information about SNMP configuration, see the network management and monitoring configuration guide for the device.
Procedure
1. Enter system view. system-view
2. Bind MIB to an IS-IS process.
isis mib-binding process-id
By default, MIB is bound to the IS-IS process with the smallest process ID.
3. Enable IS-IS notification sending. snmp-agent trap enable isis [ adjacency-state-change | area-mismatch | authentication | authentication-type | buffsize-mismatch | id-length-mismatch | lsdboverload-state-change | lsp-corrupt | lsp-parse-error | lsp-size-exceeded | manual-address-drop | max-seq-exceeded | maxarea-mismatch | own-lsp-purge | protocol-support | rejected-adjacency | skip-sequence-number | version-skew ] *
By default, IS-IS notification sending is enabled.
4. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
5. Configure the context name for the SNMP object for managing IS-IS. snmp context-name context-name
By default, no context name is set for the SNMP object for managing IS-IS.
Configuring IS-IS fast convergence
Enabling ISPF
About this task
When the network topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT.
Enabling IPv4 IS-IS ISPF
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable IPv4 IS-IS ISPF. ispf enable
By default, IPv4 IS-IS ISPF is enabled.
Enabling IPv6 IS-IS ISPF
1. Enter system view. system-view
2. Enter IS-IS view.
198
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IPv6 address family view. address-family ipv6 [ unicast ]
4. Enable IPv6 IS-IS ISPF. ispf enable
By default, IPv6 IS-IS ISPF is enabled.
Enabling prefix suppression
About this task
Perform this task to disable an interface from advertising its prefix in LSPs. This enhances network security by preventing IP routing to the interval nodes and speeds up network convergence.
Enabling IPv4 IS-IS prefix suppression
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IPv4 IS-IS prefix suppression on the interface. isis prefix-suppression
By default, IPv4 IS-IS prefix suppression is disabled on the interface.
This command is also applicable to the secondary IP address of the interface.
Enabling IPv6 IS-IS prefix suppression
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IPv6 IS-IS prefix suppression on the interface. isis ipv6 prefix-suppression
By default, IPv6 IS-IS prefix suppression is disabled on the interface.
Configuring IS-IS PIC
About this task
Prefix Independent Convergence (PIC) enables the device to speed up network convergence by ignoring the number of prefixes.
Restrictions and guidelines for IS-IS PIC
Follow these restrictions and guidelines when you configure IS-IS PIC:
•
When both IS-IS PIC and IS-IS FRR are configured, IS-IS FRR takes effect.
•
IS-IS PIC applies only to LSPs sent by neighbors.
Enabling IS-IS PIC
1. Enter system view. system-view
2. Enter IS-IS view.
199
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable PIC for IS-IS. pic [ additional-path-always ]
By default, IS-IS PIC is enabled.
Enabling BFD control packet mode for IS-IS PIC
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for IS-IS PIC. isis primary-path-detect bfd ctrl
By default, BFD control packet mode is disabled for IS-IS PIC.
To use BFD (control packet mode) to detect primary link failures, you must enable BFD control packet mode on both ends of the link.
Enabling BFD echo packet mode for IS-IS PIC
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for IS-IS PIC. isis primary-path-detect bfd echo
By default, BFD echo packet mode is disabled for IS-IS PIC.
To use BFD (echo packet mode) to detect primary link failures, you only need to enable BFD echo packet mode on one end of the link.
Enhancing IS-IS network security
To enhance the security of an IS-IS network, you can configure IS-IS authentication. IS-IS authentication involves neighbor relationship authentication, area authentication, and routing domain authentication.
Configuring neighbor relationship authentication
About this task
With neighbor relationship authentication configured, an interface adds the key in the specified mode into hello packets to the peer and checks the key in the received hello packets. If the authentication succeeds, it forms the neighbor relationship with the peer.
The authentication mode and key at both ends must be identical.
200
To prevent packet exchange failure in case of an authentication key change, configure the interface not to check the authentication information in the received packets.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify the authentication mode and key. isis [ process-id process-id ] authentication-mode { { gca key-id
{ hmac-sha-1 | hmac-sha-224 | hmac-sha-256 | hmac-sha-384 | hmac-sha-512 } [ nonstandard ] | md5 | simple } { cipher | plain } string
| keychain keychain-name } [ level-1 | level-2 ] [ ip | osi ]
By default, the authentication mode and key are not configured.
4. (Optional.) Configure the interface not to check the authentication information in the received hello packets. isis authentication send-only [ level-1 | level-2 ]
When the authentication mode and key are configured, the interface checks the authentication information in the received packets by default.
Configuring area authentication
About this task
Area authentication prevents the router from installing routing information from untrusted routers into the Level-1 LSDB. The router encapsulates the authentication key in the specified mode in Level-1 packets (LSP, CSNP, and PSNP). It also checks the key in received Level-1 packets.
Routers in a common area must have the same authentication mode and key.
To prevent packet exchange failure in case of an authentication key change, configure IS-IS not to check the authentication information in the received packets.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the area authentication mode and key. area-authentication-mode { { gca key-id { hmac-sha-1 | hmac-sha-224 | hmac-sha-256 | hmac-sha-384 | hmac-sha-512 } [ nonstandard ] | md5 | simple } { cipher | plain } string | keychain keychain-name } [ ip | osi ]
By default, the area authentication mode and key are not configured.
4. (Optional.) Configure the interface not to check the authentication information in the received
Level-1 packets, including LSPs, CSNPs, and PSNPs. area-authentication send-only
When the authentication mode and key are configured, the interface checks the authentication information in the received packets by default.
201
Configuring routing domain authentication
About this task
Routing domain authentication prevents untrusted routing information from entering into a routing domain. A router with the authentication configured encapsulates the key in the specified mode into
Level-2 packets (LSP, CSNP, and PSNP) and check the key in received Level-2 packets.
To prevent packet exchange failure in case of an authentication key change, configure IS-IS not to check the authentication information in the received packets.
Restrictions and guidelines
A router configured with routing domain authentication can establish neighbor relationships with routers not configured with routing domain authentication, but it will discard LSPs not carrying the authentication information. In this situation, IS-IS might fail to learn the expected routes. To resolve this issue, configure the same authentication mode and key on all routers in the backbone area.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the routing domain authentication mode and key. domain-authentication-mode { { gca key-id { hmac-sha-1 | hmac-sha-224
| hmac-sha-256 | hmac-sha-384 | hmac-sha-512 } [ nonstandard ] | md5 | simple } { cipher | plain } string | keychain keychain-name } [ ip | osi ]
By default, the routing domain authentication mode and key are not configured.
4. (Optional.) Configure the interface not to check the authentication information in the received
Level-2 packets, including LSPs, CSNPs, and PSNPs. domain-authentication send-only
When the authentication mode and key are configured, the interface checks the authentication information in the received packets by default.
Configuring IS-IS GR
About this task
GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.
Two routers are required to complete a GR process. The following are router roles in a GR process.
•
GR restarter —Graceful restarting router. It must have GR capability.
•
GR helper —A neighbor of the GR restarter. It assists the GR restarter to complete the GR process. By default, the device acts as the GR helper.
Configure IS-IS GR on the GR restarter.
GR restarter uses the following timers:
•
T1 timer —Specifies the times that GR restarter can send a Restart TLV with the RR bit set.
When rebooted, the GR restarter sends a Restart TLV with the RR bit set to its neighbor. If the
GR restarter receives a Restart TLV with the RA set from its neighbor before the T1 timer expires, the GR process starts. Otherwise, the GR process fails.
202
•
T2 timer —Specifies the LSDB synchronization interval. Each LSDB has a T2 timer. The
Level-1-2 router has a Level-1 timer and a Level-2 timer. If the LSDBs have not synchronized before the two timers expire, the GR process fails.
•
T3 timer —Specifies the GR interval. The GR interval is set as the holdtime in hello PDUs.
Within the interval, the neighbors maintain their adjacency with the GR restarter. If the GR process has not completed within the holdtime, the neighbors tear down the neighbor relationship and the GR process fails.
Restrictions and guidelines
Follow these restrictions and guidelines when you configure IS-IS GR:
•
The product of the T1 timer and the number of times that the T1 timer can expire must be smaller than the T2 timer.
•
The T2 timer must be smaller than the T3 timer.
•
IS-IS GR and IS-IS NSR are mutually exclusive. Do not configure them at the same time.
Procedure
1. Enter system view. system-view
2. Enable IS-IS and enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable IS-IS GR. graceful-restart
By default, the GR capability for IS-IS is disabled.
4. (Optional.) Suppress the SA bit during restart. graceful-restart suppress-sa
By default, the SA bit is not suppressed.
By enabling the GR restarter to suppress the Suppress-Advertisement (SA) bit in the hello
PDUs, the neighbors will still advertise their adjacency with the GR restarter.
5. (Optional.) Configure the T1 timer. graceful-restart t1 seconds count count
By default, the T1 timer is 3 seconds and can expire 10 times.
6. (Optional.) Configure the T2 timer. graceful-restart t2 seconds
By default, the T2 timer is 60 seconds.
7. (Optional.) Configure the T3 timer.
graceful-restart t3 seconds
By default, the T2 timer is 300 seconds.
Configuring IS-IS NSR
About this task
After an active/standby switchover, the GR restarter obtains routing information from its neighbors, and the IS-IS process must learn all the routes. If the network topology changes during the switchover, removed routes cannot be updated to the device, which can result in blackhole routes.
NSR solves the problem by backing up IS-IS link state information from the active process to the standby process. After an active/standby switchover, NSR can complete link state recovery and route regeneration without requiring the cooperation of other devices.
203
Restrictions and guidelines
IS-IS NSR and IS-IS GR are mutually exclusive. Do not configure them at the same time.
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable IS-IS NSR. non-stop-routing
By default, IS-IS NSR is disabled.
IS-IS NSR takes effect on a per-process basis. As a best practice, enable NSR for each IS-IS process.
Configuring BFD for IS-IS
About this task
BFD provides a single mechanism to quickly detect and monitor the connectivity of links between
IS-IS neighbors, reducing network convergence time. For more information about BFD, see High
Availability Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD on the interface.
IPv4: isis bfd enable
IPv6: isis ipv6 bfd enable
By default, an IS-IS interface is not enabled with BFD.
Controlling adjacency establishment and maintenance based on BFD session state
About this task
When BFD detects a Layer 3 forwarding failure between two devices, the BFD session goes down, which causes the IS-IS adjacency to go down. If Layer 2 forwarding is still available, the devices can exchange IS-IS packets and re-establish the adjacency, which might cause traffic loss.
To avoid the issue, enable this feature on the BFD-enabled interfaces of the local and remote devices. This configuration enables the interfaces to send BFD-enabled TLVs in hello packets. After the BFD session goes down, the devices do not establish an adjacency if the exchanged
BFD-enabled TLVs are identical.
If two IS-IS routers establish both IPv4 and IPv6 adjacency relationships, the IPv4 or IPv6 adjacency relationship is up only when both the IPv4 and IPv6 BFD sessions are up.
204
If two IS-IS devices establish only an IPv4 or IPv6 adjacency relationship, the adjacency relationship is up when the corresponding IPv4 or IPv6 BFD session is up.
For more information about BFD, see BFD configuration in High Availability Configuration Guide .
Enabling IPv4 IS-IS adjacency establishment and maintenance control based on BFD session state
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IPv4 IS-IS BFD on the interface. isis bfd enable
By default, IPv4 IS-IS BFD is disabled on an interface.
4. Enable adjacency establishment and maintenance control based on BFD session state. isis bfd session-restrict-adj
By default, adjacency establishment and maintenance control based on BFD session state is disabled.
配置步骤 — commi t
Enabling IPv6 IS-IS adjacency establishment and maintenance control based on BFD session state
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IPv6 IS-IS BFD on the interface. isis ipv6 bfd enable
By default, IPv6 IS-IS BFD is disabled on an interface.
4. Enable adjacency establishment and maintenance control based on BFD session state. isis ipv6 bfd session-restrict-adj
By default, adjacency establishment and maintenance control based on BFD session state is disabled.
Configuring IS-IS FRR
About IS-IS FRR
IS-IS Fast Reroute (FRR) calculates a backup path based on the LSDB and saves the backup path information to the FIB. When the primary path fails, the system immediately switches traffic to the backup path to prevent traffic loss and reduce the route convergence time.
IS-IS supports Loop Free Alternate (LFA) FRR and remote LFA FRR.
Configuring IS-IS LFA FRR
About this task
A link or router failure on a path can cause packet loss. IS-IS LFA FRR enables fast rerouting to minimize the failover time.
205
Figure 48 Network diagram for IS-IS LFA FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
In Figure 48 , after you enable LFA FRR on Router B, IS-IS automatically calculates or designates a
backup next hop when a link failure is detected. In this way, packets are directed to the backup next hop to reduce traffic recovery time. Meanwhile, IS-IS calculates the shortest path based on the new network topology, and forwards packets over the path after network convergence.
You can assign a backup next hop for IS-IS FRR through the following ways:
•
Enable IS-IS LFA FRR to calculate a backup next hop through LFA calculation.
•
Designate a backup next hop with a routing policy for routes matching specific criteria.
Restrictions and guidelines
The LFA calculation of FRR and that of TE are mutually exclusive.
Configuring IPv4 IS-IS LFA FRR to calculate a backup next hop through LFA calculation
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Disable LFA calculation on the interface. isis fast-reroute lfa-backup exclude [ level-1 | level-2 ]
By default, the interface participates in LFA calculation, and can be elected as a backup interface.
4. Return to system view. quit
5. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
6. Enable IS-IS FRR to calculate a backup next hop through LFA calculation. fast-reroute lfa [ level-1 | level-2 ]
By default, IS-IS FRR is disabled.
Configuring IPv4 LFA IS-IS FRR using a routing policy
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Disable LFA calculation on the interface. isis fast-reroute lfa-backup exclude [ level-1 | level-2 ]
By default, the interface participates in LFA calculation, and can be elected as a backup interface.
4. Return to system view.
206
quit
5. Enter IS-IS IPv4 unicast address family view. isis [ process-id ] [ vpn-instance vpn-instance-name ] address-family ipv4 [ unicast ]
6. Enable IPv4 IS-IS FRR using a routing policy.
Create a routing policy and specify a backup next hop. apply fast-reroute backup-interface
For more information about the apply fast-reroute backup-interface
command and routing policy, see Layer 3—IP Routing Configuration Guide .
Configure IPv4 IS-IS FRR. fast-reroute route-policy route-policy-name
By default, IPv4 IS-IS FRR is disabled.
Enabling BFD control packet mode for IPv4 IS-IS LFA FRR
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Enable BFD control packet mode for IPv4 IS-IS FRR. isis primary-path-detect bfd ctrl
By default, BFD control packet mode is disabled for IPv4 IS-IS FRR.
To use BFD (control packet mode) to detect primary link failures, you must enable BFD control packet mode on both ends of the link.
Enabling BFD echo packet mode for IPv4 IS-IS LFA FRR
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for IPv4 IS-IS FRR. isis primary-path-detect bfd echo
By default, BFD echo packet mode is disabled for IPv4 IS-IS FRR.
To use BFD (echo packet mode) to detect primary link failures, you only need to enable BFD echo packet mode on one end of the link.
Configuring IPv6 IS-IS LFA FRR to calculate a backup next hop through LFA calculation
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
207
3. (Optional.) Disable LFA calculation on the interface. isis ipv6 fast-reroute lfa-backup exclude [ level-1 | level-2 ]
By default, the interface participates in LFA calculation, and can be elected as a backup interface.
4. Return to system view. quit
5. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
6. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
7. Enable IPv6 IS-IS FRR to calculate a backup next hop through LFA calculation. fast-reroute lfa [ level-1 | level-2 ]
By default, IPv6 IS-IS FRR is disabled.
Configuring IPv6 IS-IS LFA FRR using a routing policy
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Disable LFA calculation on the interface. isis ipv6 fast-reroute lfa-backup exclude [ level-1 | level-2 ]
By default, the interface participates in LFA calculation, and can be elected as a backup interface.
4. Return to system view. quit
5. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
6. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
7. Enable IPv6 IS-IS FRR using a routing policy.
Create a routing policy and specify a backup next hop. apply ipv6 fast-reroute backup-interface
For more information about the apply ipv6 fast-reroute backup-interface
command and routing policy, see Layer 3—IP Routing Configuration Guide .
Configure IPv6 IS-IS FRR. fast-reroute route-policy route-policy-name
By default, IPv6 IS-IS FRR is disabled.
Enabling BFD control packet mode for IPv6 IS-IS LFA FRR
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for IPv6 IS-IS FRR. isis ipv6 primary-path-detect bfd ctrl
208
By default, BFD control packet mode is disabled for IPv6 IS-IS FRR.
To use BFD (control packet mode) to detect primary link failures, you must enable BFD control packet mode on both ends of the link.
Enabling BFD echo packet mode for IPv6 IS-IS LFA FRR
1. Enter system view. system-view
2. Configure the source IPv6 address of BFD echo packets.
bfd echo-source-ipv6 ip-address
By default, the source IPv6 address of BFD echo packets is not configured.
The source IPv6 address cannot be on the same network segment as any local interface's IPv6 address.
For more information, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for IPv6 IS-IS FRR. isis ipv6 primary-path-detect bfd echo
By default, BFD echo packet mode is disabled for IPv6 IS-IS FRR.
To use BFD (echo packet mode) to detect primary link failures, you only need to enable BFD echo packet mode on one end of the link.
Configuring IS-IS remote LFA FRR
About this task
In a ring topology where IS-IS LFA FRR cannot calculate the backup path, configure remote LFA
FRR to ensure network reliability.
Remote LFA uses the following concepts:
•
P space —Use the source node of the protected link as the root to establish a shortest path tree.
All nodes that are reachable from the source node without passing the protected link form the P space. Nodes in the P space are called P nodes.
•
Extended P space —Use the source node of the protected link and its neighbors as the roots to establish shortest path trees. All nodes that are reachable from the source node or one of its neighbors without passing the protected link form the extended P space. The P space is a subset of the extended P space.
•
Q space —Use the destination node of the protected link as the root to establish a reverse shortest path tree. All nodes that are reachable from the root node without passing the protected link form the Q space. Nodes in the Q space are called Q nodes.
•
PQ node —A PQ node refers to a node that resides in both the extended P space and the Q space. Remote LFA uses a PQ node as the destination node of a protected link.
As shown in
Figure 49 , the traffic forwarding path is PE 1—P 1—P 2—PE 2. To avoid traffic loss
caused by link failures between P 1 and P 2, the system establishes an LDP tunnel between P 1 and
P 4, which is the PQ node. When the link between P 1 and P 2 fails, P 1 encapsulates IP packets in
MPLS packets and sends the MPLS packets to P 4 through the LDP tunnel. After receiving the
MPLS packets, P 4 removes the MPLS labels of the packets and then forwards the packets to the next hop based on the IP routing table.
The system determines P 4 as the PQ node as follows:
1. Uses P 1 (source node of the protected link) and its neighbors except P 2 (which passes the protected link) as the roots to establish shortest path trees.
209
2. Finds out all nodes that are reachable from P 1 or one of its neighbors without passing the protected link, which are PE 1, P 1, P 3, and P 4.
These nodes form the extended P space.
3. Uses P 2 (destination node of the protected link) as the root to establish a reverse shortest path tree.
4. Finds out all nodes that are reachable from P 2 without passing the protected link, which are PE
2 and P 4.
These nodes form the Q space.
5. Finds out all nodes that reside in both the extended P space and the Q space.
Only P 4 resides in both the extended P space and the Q space, so P 4 is the PQ node of the protected link.
Figure 49 Network diagram for IS-IS remote LFA FRR
PE 1 P 1 P 2 PE 2
5 5
LDP Tunnel
5
10 10
Q space
Extended P space
10
P 3 P 4
PQ node
Restrictions and guidelines
To implement remote LFA FRR at a specific IS-IS level, you must enable LFA FRR for that IS-IS level.
Prerequisites
Enable MPLS and MPLS LDP on all nodes and interfaces participating in MPLS forwarding. For more information, see basic MPLS configuration and LDP configuration in MPLS Configuration
Guide .
Procedure
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv4 unicast address family view. address-family ipv4 [ unicast ]
4. Enable IS-IS remote LFA FRR. fast-reroute remote-lfa tunnel ldp [ level-1 | level-2 ]
By default, IS-IS remote LFA FRR is disabled.
5. (Optional.) Set the maximum cost from the source node of a protected link to a PQ node.
fast-reroute remote-lfa maximum-cost cost [ level-1 | level-2 ]
By default, the maximum cost from the source node of a protected link to a PQ node is
16777215.
6. (Optional.) Specify a prefix list to filter PQ nodes.
fast-reroute remote-lfa prefix-list prefix-list-name [ level-1 | level-2 ]
210
By default, no prefix list is specified to filter PQ nodes. Any PQ node can be selected as the backup next hop.
Multiple PQ nodes might reach the source node of a specific protected link. You can use this command to specify a prefix list to filter PQ nodes.
7. (Optional.) Disable remote LFA calculation on an interface. a. Return to system view. quit b. Enter interface view. interface interface-type interface-number c. Disable remote LFA calculation on the interface. isis fast-reroute remote-lfa disable [ level-1 | level-2 ]
By default, remote LFA calculation is enabled on the interface.
Setting the priority for FRR backup path selection policies
About this task
IS-IS FRR selects a backup path based on the following policies:
•
Node-protection policy —Selects the path that involves a specific node.
•
Lowest-cost policy —Selects the path that has the lowest cost.
As shown in
Figure 50 , traffic forwarding path
Device A->Device D->Device E->Device F has two backup paths. Configure this feature as follows to control backup path selection:
•
To select path Device A->Device C->Device E->Device F that involves Device C, set a higher priority for the node-protection policy than the lowest-cost policy.
•
To select path Device A->Device B->Device E->Device F that has the lowest cost, set a higher priority for the lowest-cost policy than the node-protection policy.
Figure 50 IS-IS FRR backup path selection
Device C
10
10
20
10 10
Device A
Device D Device E Device F
10 15
Device B
Restrictions and guidelines
If the node-protection policy has a higher priority but the backup path calculation fails, IS-IS uses the lowest-cost policy for further calculation. If the backup path calculation still fails, IS-IS does not perform further backup path calculation.
If the lowest-cost policy has a higher priority but the backup path calculation fails, IS-IS does not perform further backup path calculation.
Setting the priority for IPv4 IS-IS FRR backup path selection policies
1. Enter system view. system-view
211
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv4 address family view. address-family ipv4 [ unicast ]
4. Set the priority for the node-protection or lowest-cost backup path selection policy. fast-reroute tiebreaker { lowest-cost | node-protecting | srlg-disjoint } preference preference [ level-1 | level-2 ]
By default, the priority values of the node-protection, lowest-cost, and shared risk link group
(SRLG)-disjoint backup path selection policies are 40, 20, and 10, respectively.
Setting the priority for IPv6 IS-IS FRR backup path selection policies
1. Enter system view. system-view
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enter IS-IS IPv6 address family view. address-family ipv6 [ unicast ]
4. Set the priority for the node-protection or lowest-cost backup path selection policy. fast-reroute tiebreaker { lowest-cost | node-protecting | srlg-disjoint } preference preference [ level-1 | level-2 ]
By default, the priority values of the node-protection, lowest-cost, and shared risk link group
(SRLG)-disjoint backup path selection policies are 40, 20, and 10, respectively.
Verifying and maintaining IPv4 IS-IS
Verifying IPv4 IS-IS configuration and running status
Verifying basic IPv4 IS-IS configuration and running status
Perform display tasks in any view.
•
Display IS-IS process information. display isis [ process-id ]
•
Display IS-IS interface information. display isis interface [ [ interface-type interface-number ] [ verbose ]
| statistics ] [ process-id ]
•
Display IS-IS LSDB information. display isis lsdb [ [ level-1 | level-2 ] | local | lsp-id lspid |
[ lsp-name lspname ] | verbose ] * [ process-id ]
•
Display IS-IS neighbor information. display isis peer [ statistics | verbose ] [ process-id ]
•
Display IS-IS IPv4 routing information. display isis route [ ipv4 [ ip-address mask-length ] ] [ [ level-1 | level-2 ] | verbose ] * [ process-id ]
•
Display IS-IS IPv4 SPF tree information. display isis spf-tree [ ipv4 ] [ [ level-1 | level-2 ] | [ source-id source-id | verbose ] ] * [ process-id ]
212
Verifying IPv4 IS-IS route redistribution configuration
To display IS-IS redistributed IPv4 route information, execute the following command in any view: display isis redistribute [ ipv4 [ ip-address mask-length ] ] [ level-1 | level-2 ] [ process-id ]
Verifying IPv4 IS-IS system ID-to-host name mapping configuration
To display the host name-to-system ID mapping table information, execute the following command in any view: display isis name-table [ process-id ]
Verifying IPv4 IS-IS network reliability configuration
Perform display tasks in any view.
•
Display IS-IS GR information. display isis graceful-restart status [ level-1 | level-2 ]
[ process-id ]
•
Display IS-IS NSR information. display isis non-stop-routing status
Displaying and clearing IPv4 IS-IS statistics
Displaying IPv4 IS-IS statistics
Perform display tasks in any view.
•
Display global IS-IS statistics. display isis global-statistics [ public | vpn-instance vpn-instance-name ]
•
Display IS-IS LSDB statistics. display isis lsdb statistics [ level-1 | level-2 ] [ process-id ]
•
Display IS-IS packet statistics. display isis packet { csnp | hello | lsp | psnp } [ verbose ]
[ interface-type interface-number ] [ process-id ]
•
Display IS-IS statistics. display isis statistics [ ipv4 ] [ level-1 | level-1-2 | level-2 ]
[ process-id ]
Clearing IPv4 IS-IS statistics
To clear IS-IS packet statistics, execute the following command in user view: reset isis packet [ csnp | hello | lsp | psnp ] by-interface [ interface-type
interface-number ] [ process-id ]
Displaying and clearing IPv4 IS-IS log information
Displaying IPv4 IS-IS log information
Perform display tasks in any view.
•
Display IS-IS GR log information. display isis event-log graceful-restart slot slot-number
•
Display IS-IS NSR log information. display isis event-log non-stop-routing slot slot-number
213
•
Display IS-IS IPv4 route calculation log information. display isis event-log spf [ ipv4 ] [ [ level-1 | level-2 ] | verbose ] *
[ process-id ]
•
Display IS-IS LSP log information. display isis event-log lsp { purged | refreshed } [ level-1 | level-2 ]
[ process-id ]
Clearing IPv4 IS-IS log information
Perform clear tasks in user view.
•
Clear IS-IS GR log information. reset isis event-log graceful-restart slot slot-number
•
Clear IS-IS NSR log information. reset isis event-log non-stop-routing slot slot-number
•
Clear IS-IS IPv4 route calculation log information. reset isis event-log spf [ process-id ]
•
Clear IS-IS LSP log information. reset isis event-log lsp { purged | refreshed } [ process-id ]
Maintaining IPv4 IS-IS
Displaying IPv4 IS-IS OSI connection information and statistics
Perform display tasks in any view.
•
Display OSI connection information. display osi [ slot slot-number ]
•
Display OSI connection statistics. display osi statistics [ slot slot-number ]
Clearing IPv4 IS-IS data structure information and OSI statistics
Perform clear tasks in user view.
•
Clear IS-IS process data structure information. reset isis all [ process-id ] [ graceful-restart ]
This command will terminate all IS-IS neighbor relationships. Use this command when LSPs must be updated immediately.
•
Clear data structure information about an IS-IS neighbor. reset isis peer system-id [ process-id ]
Use this command when you re-establish an IS-IS neighbor relationship.
•
Clear OSI connection statistics. reset osi statistics
Verifying and maintaining IPv6 IS-IS
Verifying IPv6 IS-IS configuration and running status
Verifying basic IPv6 IS-IS configuration and running status
Perform display tasks in any view.
214
•
Display IS-IS process information. display isis [ process-id ]
•
Display IS-IS interface information. display isis interface [ [ interface-type interface-number ] [ verbose ]
| statistics ] [ process-id ]
•
Display IS-IS LSDB information. display isis lsdb [ [ level-1 | level-2 ] | local | lsp-id lspid |
[ lsp-name lspname ] | verbose ] * [ process-id ]
•
Display IS-IS neighbor information. display isis peer [ statistics | verbose ] [ process-id ]
•
Display IS-IS IPv6 routing information. display isis route ipv6 [ ipv6-address ] [ [ level-1 | level-2 ] | verbose ] * [ process-id ]
•
Display IS-IS IPv6 SPF tree information. display isis spf-tree ipv6 [ [ level-1 | level-2 ] | verbose ] *
[ process-id ]
Verifying IPv6 IS-IS route redistribution configuration
To display IS-IS redistributed IPv6 route information, execute the following command in any view: display isis redistribute ipv6 [ ipv6-address mask-length ] [ level-1 | level-2 ] [ process-id ]
Verifying IPv6 IS-IS system ID-to-host name mapping configuration
To display the host name-to-system ID mapping table information, execute the following command in any view: display isis name-table [ process-id ]
Displaying and clearing IPv6 IS-IS information
Displaying IPv6 IS-IS information
Perform display tasks in any view.
•
Display IS-IS LSDB statistics. display isis lsdb statistics [ level-1 | level-2 ] [ process-id ]
•
Display IS-IS packet statistics. display isis packet { csnp | hello | lsp | psnp } [ verbose ]
[ interface-type interface-number ] [ process-id ]
•
Display IPv6 IS-IS statistics. display isis statistics ipv6 [ level-1 | level-1-2 | level-2 ]
[ process-id ]
•
Display global IS-IS statistics. display isis global-statistics [ public | vpn-instance vpn-instance-name ]
Clearing IPv6 IS-IS statistics
To clear IS-IS packet statistics, execute the following command in user view: reset isis packet [ csnp | hello | lsp | psnp ] by-interface [ interface-type
interface-number ] [ process-id ]
215
Displaying and clearing IPv6 IS-IS log information
Displaying IPv6 IS-IS log information
Perform display tasks in any view.
•
Display IPv6 IS-IS route calculation log information. display isis event-log spf ipv6 [ [ level-1 | level-2 ] | verbose ] *
[ process-id ]
•
Display IPv6 IS-IS LSP log information. display isis event-log lsp { purged | refreshed } [ level-1 | level-2 ]
[ process-id ]
Clearing IPv6 IS-IS log information
Perform clear tasks in user view.
•
Clear IPv6 IS-IS route calculation log information. reset isis event-log spf [ process-id ]
•
Clear IPv6 IS-IS LSP log information. reset isis event-log lsp { purged | refreshed } [ process-id ]
Maintaining IPv6 IS-IS
Displaying OSI connection information and statistics
Perform display tasks in user view.
•
Display OSI connection information. display osi [ slot slot-number ]
•
Display OSI connection statistics. display osi statistics [ slot slot-number ]
Clearing IPv6 IS-IS data structure information and OSI statistics
Perform clear tasks in user view.
•
Clear IS-IS process data structure information. reset isis all [ process-id ] [ graceful-restart ]
This command will terminate all IS-IS neighbor relationships. Use this command when LSPs must be updated immediately.
•
Clear data structure information about an IS-IS neighbor. reset isis peer system-id [ process-id ]
Use this command when you re-establish an IS-IS neighbor relationship.
•
Clear OSI connection statistics. reset osi statistics
IS-IS configuration examples
Example: Configuring basic IS-IS
Network configuration
As shown in Figure 51 , Device A, Device B, Device C, and Device D reside in an AS.
216
Device A and Device B are Level-1 routers, Device D is a Level-2 router, and Device C is a Level-1-2 router connecting two areas. Device A, Device B, and Device C are in area 10, and Device D is in area 20.
Figure 51 Network diagram
Device A
L1
HGE1/0/1
10.1.1.2/24
HGE1/0/1
10.1.1.1/24
HGE1/0/3
10.1.2.1/24
Device C
L1/L2
HGE1/0/2
192.168.0.1/24
HGE1/0/2
192.168.0.2/24
Device D
L2
HGE1/0/1
172.16.1.1/16
HGE1/0/1
10.1.2.2/24 Area 20
Device B
L1
Area 10
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IS-IS:
# Configure Device A
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] is-level level-1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] is-level level-1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis enable 1
[DeviceC-HundredGigE1/0/3] quit
[DeviceC] interface hundredgige 1/0/1
217
[DeviceC-HundredGigE1/0/1] isis enable 1
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable 1
[DeviceC-HundredGigE1/0/2] quit
# Configure Device D
<DeviceD> system-view
[DeviceD] isis 1
[DeviceD-isis-1] is-level level-2
[DeviceD-isis-1] network-entity 20.0000.0000.0004.00
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis enable 1
[DeviceD-HundredGigE1/0/1] quit
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] isis enable 1
[DeviceD-HundredGigE1/0/2] quit
Verifying the configuration
# Display the IS-IS LSDB information.
[DeviceA] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
---------------------------
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
--------------------------------------------------------------------------
0000.0000.0001.00-00* 0x00000004 0xdf5e 1096 68 0/0/0
0000.0000.0002.00-00 0x00000004 0xee4d 1102 68 0/0/0
0000.0000.0002.01-00 0x00000001 0xdaaf 1102 55 0/0/0
0000.0000.0003.00-00 0x00000009 0xcaa3 1161 111 1/0/0
0000.0000.0003.01-00 0x00000001 0xadda 1112 55 0/0/0
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
[DeviceB] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
---------------------------
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
--------------------------------------------------------------------------
0000.0000.0001.00-00 0x00000006 0xdb60 988 68 0/0/0
0000.0000.0002.00-00* 0x00000008 0xe651 1189 68 0/0/0
218
0000.0000.0002.01-00* 0x00000005 0xd2b3 1188 55 0/0/0
0000.0000.0003.00-00 0x00000014 0x194a 1190 111 1/0/0
0000.0000.0003.01-00 0x00000002 0xabdb 995 55 0/0/0
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
[DeviceC] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
---------------------------
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
--------------------------------------------------------------------------
0000.0000.0001.00-00 0x00000006 0xdb60 847 68 0/0/0
0000.0000.0002.00-00 0x00000008 0xe651 1053 68 0/0/0
0000.0000.0002.01-00 0x00000005 0xd2b3 1052 55 0/0/0
0000.0000.0003.00-00* 0x00000014 0x194a 1051 111 1/0/0
0000.0000.0003.01-00* 0x00000002 0xabdb 854 55 0/0/0
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
---------------------------
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
--------------------------------------------------------------------------
0000.0000.0003.00-00* 0x00000012 0xc93c 842 100 0/0/0
0000.0000.0004.00-00 0x00000026 0x331 1173 84 0/0/0
0000.0000.0004.01-00 0x00000001 0xee95 668 55 0/0/0
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
[DeviceD] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-2 Link State Database
---------------------------
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
--------------------------------------------------------------------------
0000.0000.0003.00-00 0x00000013 0xc73d 1003 100 0/0/0
0000.0000.0004.00-00* 0x0000003c 0xd647 1194 84 0/0/0
0000.0000.0004.01-00* 0x00000002 0xec96 1007 55 0/0/0
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
219
# Display the IS-IS routing information on each device.
[DeviceA] display isis route
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
10.1.2.0/24 20 NULL HGE1/0/1 10.1.1.1 R/-/-
192.168.0.0/24 20 NULL HGE1/0/1 10.1.1.1 R/-/-
0.0.0.0/0 10 NULL HGE1/0/1 10.1.1.1 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[DeviceC] display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
10.1.2.0/24 10 NULL HGE1/0/3 Direct D/L/-
192.168.0.0/24 10 NULL HGE1/0/2 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL D/L/-
10.1.2.0/24 10 NULL D/L/-
192.168.0.0/24 10 NULL D/L/-
172.16.0.0/16 20 NULL HGE1/0/2 192.168.0.2 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[DeviceD] display isis route
Route information for IS-IS(1)
-----------------------------
220
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
192.168.0.0/24 10 NULL HGE1/0/2 Direct D/L/-
10.1.1.0/24 20 NULL HGE1/0/2 192.168.0.1 R/-/-
10.1.2.0/24 20 NULL HGE1/0/2 192.168.0.1 R/-/-
172.16.0.0/16 10 NULL HGE1/0/1 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that the routing table of Level-1 routers contains a default route with the next hop as the Level-1-2 router. The routing table of Level-2 router contains all Level-1 and Level-2 routes.
Example: Configuring DIS election
Network configuration
As shown in Figure 52 , on a broadcast network (Ethernet), Device A, Device B, Device C, and
Device D reside in IS-IS Area 10. Device A and Device B are Level-1-2 routers, Device C is a Level-1 router, and Device D is a Level-2 router.
Change the DIS priority of Device A to make it elected as the Level-1-2 DIS router.
Figure 52 Network diagram
Device A
L1/L2
Device B
L1/L2
HGE1/0/1
10.1.1.1/24
HGE1/0/1
10.1.1.2/24
HGE1/0/1
10.1.1.3/24
HGE1/0/1
10.1.1.4/24
Device C
L1
Device D
L2
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable IS-IS:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
221
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] is-level level-1
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable 1
[DeviceC-HundredGigE1/0/1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] isis 1
[DeviceD-isis-1] network-entity 10.0000.0000.0004.00
[DeviceD-isis-1] is-level level-2
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis enable 1
[DeviceD-HundredGigE1/0/1] quit
# Display information about IS-IS neighbors of Device A.
[DeviceA] display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0002
Interface: HGE1/0/1 Circuit Id: 0000.0000.0003.01
State: Up HoldTime: 21s Type: L1(L1L2) PRI: 64
System ID: 0000.0000.0003
Interface: HGE1/0/1 Circuit Id: 0000.0000.0003.01
State: Up HoldTime: 6s Type: L1 PRI: 64
System ID: 0000.0000.0002
Interface: HGE1/0/1 Circuit Id: 0000.0000.0004.01
State: Up HoldTime: 23s Type: L2(L1L2) PRI: 64
System ID: 0000.0000.0004
Interface: HGE1/0/1 Circuit Id: 0000.0000.0004.01
State: Up HoldTime: 23s Type: L2 PRI: 64
222
# Display information about IS-IS interfaces of Device A.
[DeviceA] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00001 Up Down 1 1497 L1/L2 No/No
# Display IS-IS interfaces of Device C.
[DeviceC] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00001 Up Down 1 1497 L1/L2 Yes/No
# Display information about IS-IS interfaces of Device D.
[DeviceD] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00001 Up Down 1 1497 L1/L2 No/Yes
The output shows that when the default DIS priority is used, Device C is the DIS for Level-1, and
Device D is the DIS for Level-2. The pseudonodes of Level-1 and Level-2 are
0000.0000.0003.01 and 0000.0000.0004.01.
# Configure the DIS priority of Device A.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis dis-priority 100
# Display information about IS-IS neighbors of Device A.
[DeviceA] display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0002
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 29s Type: L1(L1L2) PRI: 64
System ID: 0000.0000.0003
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 22s Type: L1 PRI: 64
System ID: 0000.0000.0002
223
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 22s Type: L2(L1L2) PRI: 64
System ID: 0000.0000.0004
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 22s Type: L2 PRI: 64
# Display information about IS-IS interfaces of Device A.
[DeviceA] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00001 Up Down 1 1497 L1/L2 Yes/Yes
The output shows that after the DIS priority configuration, Device A becomes the DIS for
Level-1-2, and the pseudonode is 0000.0000.0001.01.
# Display information about IS-IS neighbors and interfaces of Device C.
[DeviceC] display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 7s Type: L1 PRI: 100
System ID: 0000.0000.0002
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 23s Type: L1 PRI: 64
[DeviceC] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00 1 Up Down 1 1497 L1/L2 No/No
# Display information about IS-IS neighbors and interfaces of Device D.
[DeviceD] display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 7s Type: L2 PRI: 100
224
System ID: 0000.0000.0002
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 26s Type: L2 PRI: 64
[DeviceD] display isis interface
Interface information for IS-IS(1)
---------------------------------
Interface: HundredGigE1/0/1
Index IPv4 state IPv6 state Circuit ID MTU Type DIS
00001 Up Down 1 1497 L1/L2 No/No
Example: Configuring IS-IS route redistribution
Network configuration
As shown in Figure 53 , Device A, Device B, Device C, and Device D reside in the same AS. They use
IS-IS to interconnect. Device A and Device B are Level-1 routers, Device D is a Level-2 router, and
Device C is a Level-1-2 router.
Redistribute RIP routes into IS-IS on Device D.
Figure 53 Network diagram
Device A
L1
HGE1/0/1
10.1.1.2/24
HGE1/0/1
10.1.1.1/24
HGE1/0/3
10.1.2.1/24
Device C
L1/L2
HGE1/0/2
192.168.0.1/24
HGE1/0/2
192.168.0.2/24
RIP
HGE1/0/2
10.1.5.1/24
Device D
L2
HGE1/0/1
10.1.4.1/24
HGE1/0/1
10.1.4.2/24
HGE1/0/3
Device E
10.1.6.1/24
HGE1/0/1
10.1.2.2/24 Area 20
Device B
L1
Area 10
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] is-level level-1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
225
[DeviceB] isis 1
[DeviceB-isis-1] is-level level-1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable 1
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable 1
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis enable 1
[DeviceC-HundredGigE1/0/3] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] isis 1
[DeviceD-isis-1] is-level level-2
[DeviceD-isis-1] network-entity 20.0000.0000.0004.00
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis enable 1
[DeviceD-HundredGigE1/0/1] quit
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] isis enable 1
[DeviceD-HundredGigE1/0/2] quit
# Display IS-IS routing information on each Device.
[DeviceA] display isis route
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
10.1.2.0/24 20 NULL HGE1/0/1 10.1.1.1 R/-/-
192.168.0.0/24 20 NULL HGE1/0/1 10.1.1.1 R/-/-
0.0.0.0/0 10 NULL HGE1/0/1 10.1.1.1 R/-/-
226
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[DeviceC] display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
10.1.2.0/24 10 NULL HGE1/0/3 Direct D/L/-
192.168.0.0/24 10 NULL HGE1/0/2 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL D/L/-
10.1.2.0/24 10 NULL D/L/-
10.1.4.0/24 10 NULL D/L/-
192.168.0.0/24 10 NULL D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[DeviceD] display isis route
Route information for IS-IS(1)
-----------------------------
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 20 NULL HGE1/0/2 192.168.0.1 R/-/-
10.1.2.0/24 20 NULL HGE1/0/2 192.168.0.1 R/-/-
10.1.4.0/24 10 NULL HGE1/0/1 Direct D/L/-
192.168.0.0/24 10 NULL HGE1/0/2 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
3. Configure RIPv2 on Device D and Device E, and configure IS-IS to redistribute RIP routes on
Device D:
# Configure RIPv2 on Device D.
227
[DeviceD] rip 1
[DeviceD-rip-1] network 10.0.0.0
[DeviceD-rip-1] version 2
[DeviceD-rip-1] undo summary
# Configure RIPv2 on Device E.
[DeviceE] rip 1
[DeviceE-rip-1] network 10.0.0.0
[DeviceE-rip-1] version 2
[DeviceE-rip-1] undo summary
# On Device D, configure IS-IS to redistribute routes from RIP.
[DeviceD-rip-1] quit
[DeviceD] isis 1
[DeviceD–isis-1] address-family ipv4
[DeviceD–isis-1-ipv4] import-route rip level-2
# Display IS-IS routing information on Device C.
[DeviceC] display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
10.1.2.0/24 10 NULL HGE1/0/3 Direct D/L/-
192.168.0.0/24 10 NULL HGE1/0/2 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL D/L/-
10.1.2.0/24 10 NULL D/L/-
192.168.0.0/24 10 NULL D/L/-
10.1.4.0/24 20 NULL HGE1/0/2 192.168.0.2 R/L/-
10.1.5.0/24 10 0 HGE1/0/2 192.168.0.2 R/L/-
10.1.6.0/24 10 0 HGE1/0/2 192.168.0.2 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
228
Example: Configuring IS-IS authentication
Network configuration
As shown in Figure 54 , Device A, Device B, Device C, and Device D reside in the same IS-IS routing
domain.
Device A, Device B, and Device C belong to Area 10, and Device D belongs to Area 20.
•
Configure neighbor relationship authentication between neighbors.
•
Configure area authentication in Area 10 to prevent untrusted routes from entering into the area.
•
Configure routing domain authentication on Device C and Device D to prevent untrusted routes from entering the routing domain.
Figure 54 Network diagram
Device A
L1
HGE1/0/1
10.1.1.2/24
HGE1/0/3
10.1.1.1/24
HGE1/0/1
10.1.2.1/24
Device C
L1/L2
HGE1/0/1
10.1.2.2/24
HGE1/0/2
10.1.3.1/24
HGE1/0/1
10.1.3.2/24
Device D
L2
Area 20
Device B
L1
Area 10
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Device.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] is-level level-1
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] is-level level-1
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] quit
229
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable 1
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable 1
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis enable 1
[DeviceC-HundredGigE1/0/3] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] isis 1
[DeviceD-isis-1] network-entity 20.0000.0000.0001.00
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis enable 1
[DeviceD-HundredGigE1/0/1] quit
3. Configure neighbor relationship authentication between neighbors:
# Set the authentication mode to MD5 and set the plaintext key to eRq on HundredGigE 1/0/1 of
Device A and on HundredGigE 1/0/3 of Device C.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis authentication-mode md5 plain eRg
[DeviceA-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis authentication-mode md5 plain eRg
[DeviceC-HundredGigE1/0/3] quit
# Set the authentication mode to MD5 and set the plaintext key to t5Hr on HundredGigE 1/0/1 of Device B and on HundredGigE 1/0/1 of Device C.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis authentication-mode md5 plain t5Hr
[DeviceB-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis authentication-mode md5 plain t5Hr
[DeviceC-HundredGigE1/0/1] quit
# Set the authentication mode to MD5 and set the plaintext key to hSec on HundredGigE 1/0/1 of Device D and on HundredGigE 1/0/2 of Device C.
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis authentication-mode md5 plain hSec
[DeviceC-HundredGigE1/0/2] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis authentication-mode md5 plain hSec
[DeviceD-HundredGigE1/0/1] quit
4. Set the area authentication mode to MD5 and set the plaintext key to 10Sec on Device A,
Device B, and Device C.
230
[DeviceA] isis 1
[DeviceA-isis-1] area-authentication-mode md5 plain 10Sec
[DeviceA-isis-1] quit
[DeviceB] isis 1
[DeviceB-isis-1] area-authentication-mode md5 plain 10Sec
[DeviceB-isis-1] quit
[DeviceC] isis 1
[DeviceC-isis-1] area-authentication-mode md5 plain 10Sec
[DeviceC-isis-1] quit
5. Set routing domain authentication mode to MD5 and set the plaintext key to 1020Sec on Device
C and Device D.
[DeviceC] isis 1
[DeviceC-isis-1] domain-authentication-mode md5 plain 1020Sec
[DeviceC-isis-1] quit
[DeviceD] isis 1
[DeviceD-isis-1] domain-authentication-mode md5 plain 1020Sec
Example: Configuring IS-IS GR
Network configuration
As shown in Figure 55 , Device A, Device B, and Device C belong to the same IS-IS routing domain.
Run IS-IS on all the devices to interconnect them with each other.
Figure 55 Network diagram
GR restarter
Device A
HGE1/0/1
10.0.0.1/24
HGE1/0/1
10.0.0.2/24
Device B
HGE1/0/1
10.0.0.3/24
Device C
GR helper GR helper
Procedure
1. Configure the IP addresses and subnet masks for interfaces on the devices. (Details not shown.)
2. Configure IS-IS on the devices to make sure Device A, Device B, and Device C can communicate with each other at Layer 3 and dynamic route update can be implemented among them with IS-IS. (Details not shown.)
3. Enable IS-IS GR on Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] graceful-restart
[DeviceA-isis-1] return
Verifying the configuration
# Restart the IS-IS process on Device A.
<DeviceA> reset isis all 1 graceful-restart
231
Reset IS-IS process? [Y/N]:y
# Check the GR state of the IS-IS process on Device A.
<DeviceA> display isis graceful-restart status
Restart information for IS-IS(1)
--------------------------------
Restart status: COMPLETE
Restart phase: Finish
Restart t1: 3, count 10; Restart t2: 60; Restart t3: 300
SA Bit: supported
Level-1 restart information
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
Level-2 restart information
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
Example: Configuring IS-IS NSR
Network configuration
As shown in Figure 56 , Device S, Device A, and Device B belong to the same IS-IS routing domain.
•
Run IS-IS on all the devices to interconnect them with each other.
•
Enable IS-IS NSR on Device S to ensure forwarding continuity between Device A and Device B when an active/standby switchover occurs on Device S.
Figure 56 Network diagram
Loop 0
22.22.22.22/32
Device A
HGE1/0/1
12.12.12.1/24
HGE1/0/1
12.12.12.2/24
Device S
HGE1/0/1
14.14.14.1/24
HGE1/0/2
14.14.14.2/24
Device B
Loop 0
44.44.44.44/32
Procedure
1. Configure the IP addresses and subnet masks for interfaces on the devices. (Details not shown.)
2. Configure IS-IS on the devices to make sure Device S, Device A, and Device B can communicate with each other at Layer 3 and dynamic route update can be implemented among them with IS-IS. (Details not shown.)
3. Enable IS-IS NSR on Device S.
<DeviceS> system-view
[DeviceS] isis 1
[DeviceS-isis-1] non-stop-routing
[DeviceS-isis-1] return
232
Verifying the configuration
# Reoptimize process placement on Device S to trigger an active/standby switchover.
<DeviceS> system-view
[DeviceS] placement reoptimize
Predicted changes to the placement
Program Current location New location
--------------------------------------------------------------------- staticroute 0/0 0/0 rib 0/0 0/0 rib6 0/0 0/0 staticroute6 0/0 0/0 isis 0/0 1/0
Continue? [y/n]:y
Re-optimization of the placement start. You will be notified on completion.
Re-optimization of the placement complete. Use 'display placement' to view the new placement.
# During the switchover period, display IS-IS neighbor information on Device A to verify the neighborship between Device A and Device S.
<DeviceA> display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 23s Type: L1(L1L2) PRI: 64
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 28s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Device A to verify that Device A has a route to the loopback interface of Device B.
<DeviceA> display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL HGE1/0/1 Direct D/L/-
22.22.22.22/32 10 NULL Loop0 Direct D/-/-
14.14.14.0/32 10 NULL HGE1/0/1 12.12.12.2 R/L/-
44.44.44.44/32 10 NULL HGE1/0/1 12.12.12.2 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
233
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL HGE1/0/1 Direct D/L/-
22.22.22.22/32 10 NULL Loop0 Direct D/-/-
14.14.14.0/32 10 NULL
44.44.44.44/32 10 NULL
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display IS-IS neighbor information on Device B to verify the neighborship between Device B and
Device S.
<DeviceB> display isis peer
Peer information for IS-IS(1)
----------------------------
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 23s Type: L1(L1L2) PRI: 64
System ID: 0000.0000.0001
Interface: HGE1/0/1 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 28s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Device B to verify that Device B has a route to the loopback interface of Device A.
<DeviceB> display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
14.14.14.0/24 10 NULL HGE1/0/1 Direct D/L/-
44.44.44.44/32 10 NULL Loop0 Direct D/-/-
12.12.12.0/32 10 NULL HGE1/0/1 14.14.14.4 R/L/-
22.22.22.22/32 10 NULL HGE1/0/1 14.14.14.4 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
234
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
14.14.14.0/24 10 NULL HGE1/0/1 Direct D/L/-
44.44.44.44/32 10 NULL Loop0 Direct D/-/-
12.12.12.0/32 10 NULL
22.22.22.22/32 10 NULL
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that the neighbor information and routing information on Device A and Device B have not changed during the active/standby switchover on Device S. The neighbors are unaware of the switchover.
Example: Configuring BFD for IS-IS
Network configuration
•
As shown in Figure 57 , run IS-IS on Device A, Device B and Device C so that they can reach
each other at the network layer.
•
After the link over which Device A and Device B communicate through the Layer 2 switch fails,
BFD can quickly detect the failure and notify IS-IS of the failure. Device A and Device B then communicate through Device C.
Figure 57 Network diagram
Loop0
Device A
HGE1/0/1
HGE1/0/2
BFD
HGE1/0/1
Device B
L2 Switch HGE1/0/2
Loop0
Area 0
HGE1/0/1 HGE1/0/2
Device C
Table 14 Interface and IP address assignment
Device
Device A
Device C
Interface IP address
HGE1/0/1 192.168.0.102/24
HGE1/0/2
Loop0
10.1.1.102/24
121.1.1.1/32
HGE1/0/1
HGE1/0/2
10.1.1.100/24
13.1.1.2/24
Device
Device B
Procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Device A.
<DeviceA> system-view
Interface IP address
HGE1/0/1 192.168.0.100/24
HGE1/0/2
Loop0
13.1.1.1/24
120.1.1.1/32
235
[DeviceA] isis
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface loopback 0
[DeviceA-LoopBack0] isis enable
[DeviceA-LoopBack0] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] isis enable
[DeviceA-HundredGigE1/0/2] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface loopback 0
[DeviceB-LoopBack0] isis enable
[DeviceB-LoopBack0] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] isis enable
[DeviceB-HundredGigE1/0/2] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable
[DeviceC-HundredGigE1/0/2] quit
3. Configure BFD functions:
# Enable BFD and configure BFD parameters on Device A.
[DeviceA] bfd session init-mode active
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis bfd enable
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 7
# Enable BFD and configure BFD parameters on Device B.
[DeviceB] bfd session init-mode active
[DeviceB] interface hundredgige 1/0/1
236
[DeviceB-HundredGigE1/0/1] isis bfd enable
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 8
Verifying the configuration
# Display the BFD session information on Device A.
<DeviceA> display bfd session
Total sessions: 1 Up sessions: 1 Init mode: Active
IPv4 session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
3/1 192.168.0.102 192.168.0.100 Up 1700ms HGE1/0/1
# Display routes destined for 120.1.1.1/32 on Device A.
<DeviceA> display ip routing-table 120.1.1.1 verbose
Summary count : 1
Destination: 120.1.1.1/32
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 192.168.0.100
Label: NULL RealNextHop: 192.168.0.100
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device A and Device B communicate through Ethernet 1/1. Then the link over
Ethernet 1/1 fails.
# Display routes destined for 120.1.1.1/32 on Device A.
<DeviceA> display ip routing-table 120.1.1.1 verbose
Summary count : 1
237
Destination: 120.1.1.1/32
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 20 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 10.1.1.100
Label: NULL RealNextHop: 10.1.1.100
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device A and Device B communicate through Ethernet 1/2.
Example: Configuring IS-IS FRR
Network configuration
As shown in Figure 58 , Device A, Device B, and Device C reside in the same IS-IS routing domain.
•
Run IS-IS on all the devices to interconnect them with each other.
•
Configure IS-IS FRR so that when Link A fails, traffic can be switched to Link B immediately.
Figure 58 Network diagram
Device C
HGE
1/0
/1
HGE
1/0
/2
Link B
HGE
1/0
/1
Link A
Loop0
Device A
HGE1/0/2
Table 15 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Interface
HGE1/0/1
HGE1/0/2
IP address
12.12.12.1/24
13.13.13.1/24
Device
Device B
Interface
HGE1/0/1
HGE1/0/2
IP address
24.24.24.4/24
13.13.13.2/24
238
Device
Device C
Procedure
Interface
Loop0
HGE1/0/1
HGE1/0/2
IP address
1.1.1.1/32
12.12.12.2/24
24.24.24.2/24
Device Interface
Loop0
IP address
4.4.4.4/32
1. Configure IP addresses and subnet masks for interfaces on the devices. (Details not shown.)
2. Configure IS-IS on the devices to make sure Device A, Device B, and Device C can communicate with each other at the network layer. (Details not shown.)
3. Configure IS-IS FRR:
Enable IS-IS FRR to calculate a backup next hop through LFA calculation, or designate a backup next hop by using a routing policy.
(Method 1.) Enable IS-IS FRR to calculate a backup next hop through LFA calculation:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] address-family ipv4
[DeviceA-isis-1-ipv4] fast-reroute lfa
[DeviceA-isis-1-ipv4] quit
[DeviceA-isis-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] address-family ipv4
[DeviceB-isis-1-ipv4] fast-reroute lfa
[DeviceB-isis-1-ipv4] quit
[DeviceB-isis-1] quit
(Method 2.) Enable IS-IS FRR to designate a backup next hop by using a routing policy:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ip prefix-list abc index 10 permit 4.4.4.4 32
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ip address prefix-list abc
[DeviceA-route-policy-frr-10] apply fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 12.12.12.2
[DeviceA-route-policy-frr-10] quit
[DeviceA] isis 1
[DeviceA-isis-1] address-family ipv4
[DeviceA-isis-1-ipv4] fast-reroute route-policy frr
[DeviceA-isis-1-ipv4] quit
[DeviceA-isis-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ip prefix-list abc index 10 permit 1.1.1.1 32
[DeviceB] route-policy frr permit node 10
[DeviceB-route-policy-frr-10] if-match ip address prefix-list abc
239
[DeviceB-route-policy-frr-10] apply fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 24.24.24.2
[DeviceB-route-policy-frr-10] quit
[DeviceB] isis 1
[DeviceB-isis-1] address-family ipv4
[DeviceB-isis-1-ipv4] fast-reroute route-policy frr
[DeviceB-isis-1-ipv4] quit
[DeviceB-isis-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Device A to view the backup next hop information.
[DeviceA] display ip routing-table 4.4.4.4 verbose
Summary count : 1
Destination: 4.4.4.4/32
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.2
Label: NULL RealNextHop: 13.13.13.2
BkLabel: NULL BkNextHop: 12.12.12.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display route 1.1.1.1/32 on Device B to view the backup next hop information.
[DeviceB] display ip routing-table 1.1.1.1 verbose
Summary count : 1
Destination: 1.1.1.1/32
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
IpPre: N/A QosLocalID: N/A
240
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 0.0.0.0
Flags: 0x1008c OrigNextHop: 13.13.13.1
Label: NULL RealNextHop: 13.13.13.1
BkLabel: NULL BkNextHop: 24.24.24.2
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
Example: Configuring IS-IS remote LFA FRR
Network configuration
As shown in Figure 58 , Device A, Device B, Device C, and Device D reside in the same IS-IS routing
domain.
•
Run IS-IS on all the devices to interconnect them with each other.
•
Configure MPLS LDP on all the devices.
•
Configure IS-IS remote LFA FRR so that when Link A fails, traffic can be switched to Link B immediately.
Figure 59 Network diagram
Loop1
1.1.1.1/32
Loop1
2.2.2.2/32
Device A
HGE1/0/2
HGE1/0/
1 cost 10
Link A
HGE1/0/
1
Device B
HGE1/0/2 cost 20 cost 20
HGE1/0/1
Device C
Link B
HGE1/0/2 cost 20
HGE1/0/2
HGE1/0/1
Device D
Loop1
3.3.3.3/32
Loop1
4.4.4.4/32
Table 16 Interface and IP address assignment
Device
Device A
Interface
HGE1/0/1
IP address
12.12.12.1/24
Device
Device B
241
Interface
HGE1/0/1
IP address
12.12.12.2/24
Device
Device C
Interface
HGE1/0/2
Loop1
HGE1/0/1
HGE1/0/2
Loop1
IP address
13.13.13.1/24
1.1.1.1/32
13.13.13.2/24
14.14.14.1/24
3.3.3.3/32
Device
Device D
Interface
HGE1/0/2
Loop1
HGE1/0/1
HGE1/0/2
Loop1
IP address
15.15.15.1/24
2.2.2.2/32
15.15.15.2/24
14.14.14.2/24
4.4.4.4/32
Procedure
1. Configure IP addresses and subnet masks for interfaces on the devices. (Details not shown.)
2. Configure IS-IS and MPLS LDP on all the devices:
# Configure Device A.
<DeviceA> system-view
[DeviceA] mpls lsr-id 1.1.1.1
[DeviceA] mpls ldp
[DeviceA-ldp] accept target-hello all
[DeviceA-ldp] quit
[DeviceA] isis 1
[DeviceA-isis-1] network-entity 00.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] isis cost 10
[DeviceA-HundredGigE1/0/1] mpls enable
[DeviceA-HundredGigE1/0/1] mpls ldp enable
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] isis enable 1
[DeviceA-HundredGigE1/0/2] isis cost 20
[DeviceA-HundredGigE1/0/2] mpls enable
[DeviceA-HundredGigE1/0/2] mpls ldp enable
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface loopback 1
[DeviceA-LoopBack1] isis enable 1
[DeviceA-LoopBack1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] mpls lsr-id 2.2.2.2
[DeviceB] mpls ldp
[DeviceB-ldp] accept target-hello all
[DeviceB-ldp] quit
[DeviceB] isis 1
[DeviceB-isis-1] network-entity 00.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] isis cost 10
[DeviceB-HundredGigE1/0/1] mpls enable
242
[DeviceB-HundredGigE1/0/1] mpls ldp enable
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] isis enable 1
[DeviceB-HundredGigE1/0/2] isis cost 20
[DeviceB-HundredGigE1/0/2] mpls enable
[DeviceB-HundredGigE1/0/2] mpls ldp enable
[DeviceB-HundredGigE1/0/2] quit
[DeviceB] interface loopback 1
[DeviceB-LoopBack1] isis enable 1
[DeviceB-LoopBack1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] mpls lsr-id 3.3.3.3
[DeviceC] mpls ldp
[DeviceC-ldp] accept target-hello all
[DeviceC-ldp] quit
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 00.0000.0000.0003.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable 1
[DeviceC-HundredGigE1/0/1] isis cost 20
[DeviceC-HundredGigE1/0/1] mpls enable
[DeviceC-HundredGigE1/0/1] mpls ldp enable
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable 1
[DeviceC-HundredGigE1/0/2] isis cost 20
[DeviceC-HundredGigE1/0/2] mpls enable
[DeviceC-HundredGigE1/0/2] mpls ldp enable
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface loopback 1
[DeviceC-LoopBack1] isis enable 1
[DeviceC-LoopBack1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] mpls lsr-id 4.4.4.4
[DeviceD] mpls ldp
[DeviceD-ldp] accept target-hello all
[DeviceD-ldp] quit
[DeviceD] isis 1
[DeviceD-isis-1] network-entity 00.0000.0000.0004.00
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis enable 1
[DeviceD-HundredGigE1/0/1] isis cost 20
[DeviceD-HundredGigE1/0/1] mpls enable
243
[DeviceD-HundredGigE1/0/1] mpls ldp enable
[DeviceD-HundredGigE1/0/1] quit
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] isis enable 1
[DeviceD-HundredGigE1/0/2] isis cost 20
[DeviceD-HundredGigE1/0/2] mpls enable
[DeviceD-HundredGigE1/0/2] mpls ldp enable
[DeviceD-HundredGigE1/0/2] quit
[DeviceD] interface loopback 1
[DeviceD-LoopBack1] isis enable 1
[DeviceD-LoopBack1] quit
3. Configure IS-IS remote LFA FRR.
[DeviceA] isis 1
[DeviceA-isis-1] address-family ipv4
[DeviceA-isis-1-ipv4] fast-reroute lfa
[DeviceA-isis-1-ipv4] fast-reroute remote-lfa tunnel ldp
[DeviceA-isis-1-ipv4] quit
[DeviceA-isis-1] quit
Verifying the configuration
# Display route 2.2.2.2/32 on Device A to view the backup next hop information.
[DeviceA] display isis route ipv4 2.2.2.2 32 verbose
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Dest : 2.2.2.2/32 Int. Cost : 10 Ext. Cost : NULL
Admin Tag : - Src Count : 1 Flag : R/L/-
InLabel : 4294967295 InLabel Flag: -/-/-/-/-/-
NextHop : Interface : ExitIndex :
12.12.12.2 HGE1/0/1 0x00000002
Nib ID : 0x14000008 OutLabel : 4294967295 OutLabelFlag: -
LabelSrc : N/A Delay Flag : N/A
Remote-LFA:
Interface : HGE1/0/2
BkNextHop : 13.13.13.2 LsIndex : 0x01000002
Tunnel destination address: 4.4.4.4
Backup label: {1149}
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
InLabel flags: R-Readvertisement, N-Node SID, P-no PHP
E-Explicit null, V-Value, L-Local
OutLabelFlags: E-Explicit null, I-Implicit null, N-Nomal, P-SR label prefer
244
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Dest : 2.2.2.2/32 Int. Cost : 10 Ext. Cost : NULL
Admin Tag : - Src Count : 3 Flag : -/-/-
InLabel : 4294967295 InLabel Flag: -/-/-/-/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
InLabel flags: R-Readvertisement, N-Node SID, P-no PHP
E-Explicit null, V-Value, L-Local
OutLabelFlags: E-Explicit null, I-Implicit null, N-Nomal, P-SR label prefer
Example: Configuring IS-IS multi-instance processes
Network configuration
As shown in Figure 60 , the IPv4 and IPv6 costs are different on an interface. Configure IS-IS
multi-instance processes to isolate the IPv4 and IPv6 network and avoid IPv6 route calculation errors.
Figure 60 Network diagram
Loop0 Loop0
IPv4 cost = 10
HGE1/0/1 HGE1/0/1
IPv6 cost = 63
Device A Device B
Table 17 Interface and IP address assignment
Device
Device A
Device B
Prerequisties
Interface
HGE1/0/1
Loop0
HGE1/0/1
Loop0
IPv4 address
10.1.1.1/24
1.1.1.1/32
10.1.1.2/24
2.2.2.2/32
IPv6 address
2001::1/64
10::1/128
2001::2/64
20::1/128
Configure IPv4 and IPv6 addresses for the interfaces. (Details not shown.)
Procedure
1. Configure traditional IPv4 IS-IS processes:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] quit
[DeviceA] interface loopback 0
[DeviceA-LoopBack0] isis enable
[DeviceA-LoopBack0] quit
245
[DeviceA] interface loopback 0
[DeviceA-LoopBack0] isis ipv6 enable 2
[DeviceA-LoopBack0] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface loopback 0
[DeviceB-LoopBack0] isis enable
[DeviceB-LoopBack0] quit
[DeviceB] interface loopback 0
[DeviceB-LoopBack0] isis ipv6 enable 2
[DeviceB-LoopBack0] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis enable 1
[DeviceB-HundredGigE1/0/1] quit
2. Configure IPv6 IS-IS multi-instance processes:
# Configure Device A.
[DeviceA] isis 2
[DeviceA-isis-2] network-entity 20.0000.0000.0010.00
[DeviceA-isis-2] multi-instance enable iid 1
[DeviceA-isis-2] address-family ipv6
[DeviceA-isis-2-ipv6] quit
[DeviceA-isis-2] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis ipv6 enable 2
[DeviceA-HundredGigE1/0/1] isis process-id 2 cost 63
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
[DeviceB] isis 2
[DeviceB-isis-2] network-entity 20.0000.0000.0020.00
[DeviceB-isis-2] multi-instance enable iid 1
[DeviceB-isis-2] address-family ipv6
[DeviceB-isis-2-ipv6] quit
[DeviceB-isis-2] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis ipv6 enable 2
[DeviceB-HundredGigE1/0/1] isis process-id 2 cost 63
[DeviceB-HundredGigE1/0/1] quit
Verifying the configuration
# View information about the IPv4 IS-IS routing table of Device A.
[DeviceA] display isis route ipv4
246
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
1.1.1.1/32 0 NULL Loop0 Direct D/L/-
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
2.2.2.2/32 10 NULL HGE1/0/1 10.1.1.2 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
1.1.1.1/32 0 NULL Loop0 Direct D/L/-
10.1.1.0/24 10 NULL ULL Direct D/L/-
2.2.2.2/32 10 NULL
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that route calculation results are correct.
# View information about the IPv4 IS-IS routing table of Device B.
[DeviceB] display isis route ipv4
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
1.1.1.1/32 10 NULL HGE1/0/1 10.1.1.1 R/L/-
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
2.2.2.2/32 0 NULL Loop0 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
1.1.1.1/32 10 NULL
247
10.1.1.0/24 10 NULL HGE1/0/1 Direct D/L/-
2.2.2.2/32 0 NULL Loop0 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that route calculation results are correct.
# View information about the IPv6 IS-IS routing table of Device A.
[DeviceA] display isis route ipv6
Route information for IS-IS(2)
------------------------------
Level-1 IPv6 forwarding table
-----------------------------
Destination : 10::1 PrefixLen: 128
Flag : D/L/- Cost : 0
Next hop : Direct Interface: Loop0
Destination : 2001:: PrefixLen: 64
Flag : D/L/- Cost : 63
Next hop : Direct Interface: HGE1/0/1
Destination : 20::1 PrefixLen: 128
Flag : R/L/- Cost : 63
Next hop : FE80::861F:31FF:FE6D:201 Interface: HGE1/0/1
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv6 forwarding table
-----------------------------
Destination : 10::1 PrefixLen: 128
Flag : D/L/- Cost : 0
Next hop : Direct Interface: Loop0
Destination : 2001:: PrefixLen: 64
Flag : D/L/- Cost : 63
Next hop : Direct Interface: HGE1/0/1
Destination : 20::1 PrefixLen: 128
Flag : -/-/- Cost : 63
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that route calculation results are correct.
# View information about the IPv6 IS-IS routing table of Device B.
[DeviceB] display isis route ipv6
248
Route information for IS-IS(2)
------------------------------
Level-1 IPv6 forwarding table
-----------------------------
Destination : 10::1 PrefixLen: 128
Flag : R/L/- Cost : 63
Next hop : FE80::861F:29FF:FE93:101 Interface: HGE1/0/1
Destination : 2001:: PrefixLen: 64
Flag : D/L/- Cost : 63
Next hop : Direct Interface: HGE1/0/1
Destination : 20::1 PrefixLen: 128
Flag : D/L/- Cost : 0
Next hop : Direct Interface: Loop0
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv6 forwarding table
-----------------------------
Destination : 10::1 PrefixLen: 128
Flag : -/-/- Cost : 63
Destination : 2001:: PrefixLen: 64
Flag : D/L/- Cost : 63
Next hop : Direct Interface: HGE1/0/1
Destination : 20::1 PrefixLen: 128
Flag : D/L/- Cost : 0
Next hop : Direct Interface: Loop0
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that route calculation results are correct.
IPv6 IS-IS configuration examples
Example: Configuring IPv6 IS-IS basics
Network configuration
As shown in Figure 61 , Device A, Device B, Device C, and Device D, all enabled with IPv6, reside in
the same AS. Configure IPv6 IS-IS on the devices so that they can reach each other.
Device A and Device B are Level-1 routers, Device D is a Level-2 router, and Device C is a Level-1-2 router.
249
Figure 61 Network diagram
Device A
L1
HGE1/0/1
2001:1::2/64
HGE1/0/2
2001:1::1/64
HGE1/0/1
2001:2::1/64
Device C
L1/L2
HGE1/0/3
2001:3::1/64
HGE1/0/1
2001:3::2/64
Device D
L2
HGE1/0/2
2001:4::1/64
HGE1/0/1
2001:2::2/64 Area 20
Device B
L1
Area 10
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 IS-IS:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] is-level level-1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] address-family ipv6
[DeviceA-isis-1-ipv6] quit
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceA-HundredGigE1/0/1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] is-level level-1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] address-family ipv6
[DeviceB-isis-1-ipv6] quit
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceB-HundredGigE1/0/1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] address-family ipv6
[DeviceC-isis-1-ipv6] quit
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
250
[DeviceC-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis ipv6 enable 1
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis ipv6 enable 1
[DeviceC-HundredGigE1/0/3] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] isis 1
[DeviceD-isis-1] is-level level-2
[DeviceD-isis-1] network-entity 20.0000.0000.0004.00
[DeviceD-isis-1] address-family ipv6
[DeviceD-isis-1-ipv6] quit
[DeviceD-isis-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceD-HundredGigE1/0/1] quit
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] isis ipv6 enable 1
[DeviceD-HundredGigE1/0/2] quit
Verifying the configuration
# Display the IPv6 IS-IS routing table on Device A.
[DeviceA] display isis route ipv6
Route information for IS-IS(1)
------------------------------
Level-1 IPv6 forwarding table
-----------------------------
Destination : :: PrefixLen: 0
Flag : R/-/- Cost : 10
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : Direct Interface: HGE1/0/1
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:3:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
251
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Device B.
[DeviceB] display isis route ipv6
Route information for IS-IS(1)
------------------------------
Level-1 IPv6 forwarding table
-----------------------------
Destination : :: PrefixLen: 0
Flag : R/-/- Cost : 10
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : Direct Interface: HGE1/0/1
Destination : 2001:3:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Device C.
[DeviceC] display isis route ipv6
Route information for IS-IS(1)
------------------------------
Level-1 IPv6 forwarding table
-----------------------------
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : Direct Interface: HGE1/0/2
Destination : 2001:2:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : Direct Interface: HGE1/0/1
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : Direct Interface: HGE1/0/3
252
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv6 forwarding table
-----------------------------
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Destination : 2001:2:: PrefixLen: 64
Flag : D/L/- Cost : 10
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Destination : 2001:4:: PrefixLen: 64
Flag : R/-/- Cost : 10
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Device D.
[DeviceD] display isis route ipv6
Route information for IS-IS(1)
------------------------------
Level-2 IPv6 forwarding table
-----------------------------
Destination : 2001:1:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next hop : FE80::200:FF:FE0F:4 Interface: HGE1/0/1
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next hop : Direct Interface: HGE1/0/1
Destination : 2001:4:: PrefixLen: 64
Flag : D/L/- Cost : 0
Next hop : Direct Interface: HGE1/0/2
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
253
Example: Configuring BFD for IPv6 IS-IS
Network configuration
•
Configure IPv6 IS-IS on Device A, Device B, and Device C so that they can reach each other.
•
Enable BFD on HundredGigE 1/0/1 of Device A and Device B.
When the link between Device B and the Layer 2 switch fails, BFD can quickly detect the failure and notify IPv6 IS-IS of the failure. Then Device A and Device B communicate through Device C.
Figure 62 Network diagram
2001:1::/64
Device A
HGE1/0/1
HGE1/0/2
BFD
HGE1/0/1
Device B
2001:4::/64
L2 Switch HGE1/0/2
Area 0
HGE1/0/1 HGE1/0/2
Device C
Table 18 Interface and IP address assignment
Device
Device A
Device C
Interface IPv6 address
HGE1/0/1 2001::1/64
HGE1/0/2 2001:2::1/64
HGE1/0/1
HGE1/0/2
2001:2::2/64
2001:3::1/64
Device
Device B
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 IS-IS:
# Configure Device A.
<DeviceA> system-view
[DeviceA] isis 1
[DeviceA-isis-1] is-level level-1
[DeviceA-isis-1] network-entity 10.0000.0000.0001.00
[DeviceA-isis-1] address-family ipv6
[DeviceA-isis-1-ipv6] quit
[DeviceA-isis-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] isis ipv6 enable 1
[DeviceA-HundredGigE1/0/2] quit
Interface
HGE1/0/1
HGE1/0/2
254
IPv6 address
2001::2/64
2001:3::2/64
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] is-level level-1
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] address-family ipv6
[DeviceB-isis-1-ipv6] quit
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] isis ipv6 enable 1
[DeviceB-HundredGigE1/0/2] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis 1
[DeviceC-isis-1] network-entity 10.0000.0000.0003.00
[DeviceC-isis-1] address-family ipv6
[DeviceC-isis-1-ipv6] quit
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis ipv6 enable 1
[DeviceC-HundredGigE1/0/1 quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis ipv6 enable 1
[DeviceC-HundredGigE1/0/2] quit
3. Configure BFD functions:
# Enable BFD and configure BFD parameters on Device A.
[DeviceA] bfd session init-mode active
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] isis ipv6 bfd enable
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 7
[DeviceA-HundredGigE1/0/1] return
# Enable BFD and configure BFD parameters on Device B.
[DeviceB] bfd session init-mode active
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] isis ipv6 bfd enable
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 6
Verifying the configuration
# Display BFD session information on Device A.
<DeviceA> display bfd session
Total sessions: 1 Up sessions: 1 Init mode: Active
255
IPv6 session working in control packet mode:
Local Discr: 1441 Remote Discr: 1450
Source IP: FE80::20F:FF:FE00:1202 (link-local address of HundredGigE1/0/1 on
Device A)
Destination IP: FE80::20F:FF:FE00:1200 (link-local address of HundredGigE1/0/1 on
Device B)
Session State: Up Interface: HGE1/0/1
Hold Time: 2319ms
# Display routes destined for 2001:4::0/64 on Device A.
<DeviceA> display ipv6 routing-table 2001:4::0 64
Summary count : 2
Destination: 2001:4::/64 Protocol : IS_L1
NextHop : FE80::20F:FF:FE00:1200 Preference: 15
Interface : HGE1/0/1 Cost : 10
The output shows that Device A and Device B communicate through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display routes destined for 2001:4::0/64 on Device A.
<DeviceA> display ipv6 routing-table 2001:4::0 64
Summary count : 1
Destination: 2001:4::/64 Protocol : IS_L1
NextHop : FE80::BAAF:67FF:FE27:DCD0 Preference: 15
Interface : HGE1/0/2 Cost : 20
The output shows that Device A and Device B communicate through HundredGigE 1/0/2.
Example: Configuring IPv6 IS-IS FRR
Network configuration
As shown in Figure 63 , Device A, Device B, and Device C reside in the same IS-IS routing domain.
•
Run IPv6 IS-IS on all the devices to interconnect them with each other.
•
Configure IPv6 IS-IS FRR so that when Link A fails, traffic can be switched to Link B immediately.
Figure 63 Network diagram
Device C
HGE
1/0
/1
HGE
1/0
/2
Link B
HGE
1/0
/1
Link A
HGE
1/0
/1
Loop0 Loop0
Device A
HGE1/0/2 HGE1/0/2
Device B
256
Table 19 Interface and IP address assignment
Device
Device A
Device C
Procedure
Interface
HGE1/0/1
HGE1/0/2
Loop0
HGE1/0/1
HGE1/0/2
IPv6 address
1::1/64
2::1/64
10::1/128
1::2/64
3::2/64
Device
Device B
Interface
HGE1/0/1
HGE1/0/2
Loop0
IP address
3::1/64
2::2/64
20::1/128
1. Configure IPv6 addresses for interfaces on the devices and enable IPv6 IS-IS. (Details not shown.)
2. Configure IPv6 IS-IS FRR:
Enable IPv6 IS-IS FRR to calculate a backup next hop through LFA calculation, or designate a backup next hop by using a routing policy.
(Method 1.) Enable IPv6 IS-IS FRR to calculate a backup next hop through LFA calculation:
# Configure Device A.
<DeviceA>system-view
[DeviceA] isis 1
[DeviceA-isis-1] address-family ipv6
[DeviceA-isis-1-ipv6] fast-reroute lfa
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis 1
[DeviceB-isis-1] address-family ipv6
[DeviceB-isis-1-ipv6] fast-reroute lfa
(Method 2.) Enable IPv6 IS-IS FRR to designate a backup next hop by using a routing policy:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ipv6 prefix-list abc index 10 permit 20::1 128
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceA-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 1::2
[DeviceA-route-policy-frr-10] quit
[DeviceA] isis 1
[DeviceA-isis-1] address-family ipv6
[DeviceA-isis-1-ipv6] fast-reroute route-policy frr
[DeviceA-isis-1-ipv6] quit
[DeviceA-isis-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ipv6 prefix-list abc index 10 permit 10::1 128
[DeviceB] route-policy frr permit node 10
[DeviceB-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceB-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 3::2
257
[DeviceB-route-policy-frr-10] quit
[DeviceB] isis 1
[DeviceB-isis-1] address-family ipv6
[DeviceB-isis-1-ipv6] fast-reroute route-policy frr
[DeviceB-isis-1-ipv6] quit
[DeviceB-isis-1] quit
Verifying the configuration
# Display route 20::1/128 on Device A to view the backup next hop information.
[DeviceA] display ipv6 routing-table 20::1 128 verbose
Summary count : 1
Destination: 20::1/128
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 00h27m45s
Cost: 10 Preference: 15
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0xa OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x24000005 LastAs: 0
AttrID: 0xffffffff Neighbor: ::
Flags: 0x10041 OrigNextHop: FE80::34CD:9FF:FE2F:D02
Label: NULL RealNextHop: FE80::34CD:9FF:FE2F:D02
BkLabel: NULL BkNextHop: FE80::7685:45FF:FEAD:102
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
VpnPeerId: N/A Dscp: N/A
Exp: N/A
# Display route 10::1/128 on Device B to view the backup next hop information.
[DeviceB] display ipv6 routing-table 10::1 128 verbose
Summary count : 1
Destination: 10::1/128
Protocol: IS_L1
Process ID: 1
SubProtID: 0x1 Age: 00h33m23s
Cost: 10 Preference: 15
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0xa OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x24000006 LastAs: 0
AttrID: 0xffffffff Neighbor: ::
258
Flags: 0x10041 OrigNextHop: FE80::34CC:E8FF:FE5B:C02
Label: NULL RealNextHop: FE80::34CC:E8FF:FE5B:C02
BkLabel: NULL BkNextHop: FE80::7685:45FF:FEAD:102
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
VpnPeerId: N/A Dscp: N/A
Exp: N/A
259
BGP overview
Border Gateway Protocol (BGP) is an exterior gateway protocol (EGP). It is called internal BGP
(IBGP) when it runs within an AS and called external BGP (EBGP) when it runs between ASs. The current version in use is BGP-4 (RFC 4271).
BGP characteristics
BGP has the following characteristics:
•
Focuses on route control and selection rather than route discovery and calculation.
•
Uses TCP to enhance reliability.
•
Measures the distance of a route by using a list of ASs that the route must travel through to reach the destination. BGP is also called a path-vector protocol.
•
Supports CIDR.
•
Reduces bandwidth consumption by advertising only incremental updates. BGP is very suitable to advertise large numbers of routes on the Internet.
•
Eliminates routing loops by adding AS path information to BGP route updates.
•
Uses policies to implement flexible route filtering and selection.
•
Has good scalability.
BGP speaker and BGP peer
A router running BGP is a BGP speaker. A BGP speaker establishes peer relationships with other
BGP speakers to exchange routing information over TCP connections.
Based on the AS, a BGP peer can be either of the following types:
•
IBGP peer —Resides in the same AS as the local router.
•
EBGP peer —Resides in different ASs from the local router.
Based on the IP version, a BGP peer can be either of the following types:
•
IPv4 peer —Uses an IPv4 address to establish a peer relationship with the local router.
•
IPv6 peer —Uses an IPv6 address to establish a peer relationship with the local router.
BGP message types
BGP uses the following message types:
•
Open —After establishing a TCP connection, BGP sends an OPEN message to establish a session to the peer.
•
Update —BGP sends UPDATE messages to exchange routing information between peers.
Each UPDATE message can advertise a group of feasible routes with identical attributes and multiple withdrawn routes.
•
Keepalive —BGP sends KEEPALIVE messages between peers to maintain connectivity.
•
Route-refresh —BGP sends a ROUTE-REFRESH message to request the routing information for a specific address family from a peer.
•
Notification —BGP sends a NOTIFICATION message upon detecting an error and immediately closes the connection.
260
BGP path attributes
BGP uses the following path attributes in UPDATE messages for route filtering and selection:
ORIGIN
The ORIGIN attribute specifies the origin of BGP routes. This attribute has the following types:
•
IGP —Has the highest priority. Routes generated in the local AS have the IGP attribute.
•
EGP —Has the second highest priority. Routes obtained through EGP have the EGP attribute.
•
INCOMPLETE —Has the lowest priority. The source of routes with this attribute is unknown.
Routes redistributed from other routing protocols have the INCOMPLETE attribute.
AS_PATH
The AS_PATH attribute identifies the ASs through which a route has passed. Before advertising a route to another AS, BGP adds the local AS number into the AS_PATH attribute, so the receiver can determine ASs to route the message back.
The AS_PATH attribute has the following types:
•
AS_SEQUENCE
—Arranges AS numbers in sequence. As shown in Figure 64 , the number of
the AS closest to the receiver's AS is leftmost.
•
AS_SET —Arranges AS numbers randomly.
Figure 64 AS_PATH attribute
D = 8.0.0.0
AS_PATH = 10
AS 20
8.0.0.0
AS 10
D = 8.0.0.0
AS_PATH = 10
AS 40
D = 8.0.0.0
AS_PATH = 20, 10
D = 8.0.0.0
AS_PATH = 30, 20, 10
D = 8.0.0.0
AS_PATH = 40, 10
AS 30 AS 50
BGP uses the AS_PATH attribute to implement the following functions:
•
Avoid routing loops —A BGP router does not receive routes containing the local AS number to avoid routing loops.
•
Affect route selection —BGP gives priority to the route with the shortest AS_PATH length if
other factors are the same. As shown in Figure 64 , the BGP router in AS 50 gives priority to the
route passing AS 40 for sending data to the destination 8.0.0.0. In some applications, you can apply a routing policy to control BGP route selection by modifying the AS_PATH length. For
more information about routing policy, see " Configuring routing policies ."
261
•
Filter routes —By using an AS path list, you can filter routes based on AS numbers contained
NEXT_HOP
The NEXT_HOP attribute may not be the IP address of a directly connected router. Its value is determined as follows:
•
When a BGP speaker advertises a self-originated route to a BGP peer, it sets the address of the sending interface as the NEXT_HOP.
•
When a BGP speaker sends a received route to an EBGP peer, it sets the address of the sending interface as the NEXT_HOP.
•
When a BGP speaker sends a route received from an EBGP peer to an IBGP peer, it does not modify the NEXT_HOP attribute. If load balancing is configured, BGP modifies the NEXT_HOP
attribute for the equal-cost routes. For load balancing information, see " BGP load balancing ."
Figure 65 NEXT_HOP attribute
D = 8.0.0.0
Next_hop = 1.1.1.1
AS 200
AS 100
1.1.2.1/24
EBGP
1.1.1.1/24
8.0.0.0
EBGP
D = 8.0.0.0
Next_hop = 1.1.2.1
AS 300
IBGP
D = 8.0.0.0
Next_hop = 1.1.2.1
MED (MULTI_EXIT_DISC)
BGP advertises the MED attribute between two neighboring ASs, each of which does not advertise the attribute to any other AS.
Similar to metrics used by IGPs, MED is used to determine the optimal route for traffic going into an
AS. When a BGP router obtains multiple routes to the same destination but with different next hops,
from AS 10 to AS 20 travels through Router B that is selected according to MED.
262
Figure 66 MED attribute
2.1.1.1
MED = 0
Router B
D = 9.0.0.0
Next_hop = 2.1.1.1
MED = 0
EBGP
Router A IBGP
IBGP
9.0.0.0
Router D
D = 9.0.0.0
Next_hop = 3.1.1.1
MED = 100
EBGP IBGP
AS 10
3.1.1.1
MED = 100
Router C
AS 20
Generally BGP only compares MEDs of routes received from the same AS. You can also use the compare-different-as-med command to force BGP to compare MED values of routes received from different ASs.
LOCAL_PREF
The LOCAL_PREF attribute is exchanged between IBGP peers only, and is not advertised to any other AS. It indicates the priority of a BGP router.
BGP uses LOCAL_PREF to determine the optimal route for traffic leaving the local AS. When a BGP router obtains multiple routes to the same destination but with different next hops, it selects the route
with the highest LOCAL_PREF value as the optimal route. As shown in Figure 67 , traffic from AS 20
to AS 10 travels through Router C that is selected according to LOCAL_PREF.
263
Figure 67 LOCAL_PREF attribute
Local_pref = 100
Router B
8.0.0.0
2.1.1.1
Router A
3.1.1.1
EBGP
IBGP
IBGP D = 8.0.0.0
Next_hop = 2.1.1.1
Local_pref = 100
Router D
D = 8.0.0.0
Next_hop = 3.1.1.1
Local_pref = 200 EBGP IBGP
AS 10
Router C
AS 20
Local_pref = 200
COMMUNITY
The COMMUNITY attribute identifies the community of BGP routes. A BGP community is a group of routes with the same characteristics. It has no geographical boundaries. Routes of different ASs can belong to the same community.
A route can carry one or more COMMUNITY attribute values (each of which is represented by a
4-byte integer). A router uses the COMMUNITY attribute to determine whether to advertise the route and the advertising scope without using complex filters such as ACLs. This mechanism simplifies routing policy configuration, management, and maintenance.
Well-known COMMUNITY attributes involve the following:
•
INTERNET —By default, all routes belong to the Internet community. Routes with this attribute can be advertised to all BGP peers.
•
NO_EXPORT —Routes with this attribute cannot be advertised out of the local AS or out of the local confederation, but can be advertised to other sub-ASs in the confederation. For
confederation information, see " Settlements for problems in large-scale BGP networks ."
•
No_ADVERTISE —Routes with this attribute cannot be advertised to other BGP peers.
•
No_EXPORT_SUBCONFED —Routes with this attribute cannot be advertised out of the local
AS or other sub-ASs in the local confederation.
You can configure BGP community lists to filter BGP routes based on the BGP COMMUNITY attribute.
Extended community attribute
To meet new demands, BGP defines the extended community attribute. The extended community attribute has the following advantages over the COMMUNITY attribute:
•
Provides more attribute values by extending the attribute length to eight bytes.
•
Allows for using different types of extended community attributes in different scenarios to enhance route filtering and control and simplify configuration and management.
The device supports the route target attribute and Site of Origin (SoO) extended community attribute.
For information about route target, see MPLS Configuration Guide .
264
The SoO attribute specifies the site where the route originated. It prevents advertising a route back to the originating site. If the AS-path attribute is lost, the router can use the SoO attribute to avoid routing loops.
The SoO attribute has the following formats:
•
16-bit AS number:32-bit user-defined number . For example, 100:3.
•
32-bit IP address:16-bit user-defined number . For example, 192.168.122.15:1.
•
32-bit AS number:16-bit user-defined number , where the minimum value of the AS number is
65536. For example, 65536:1.
•
32-bit IP address/IPv4 address mask length:16-bit user-defined number . For example,
192.168.122.15/24:1.
•
32-bit AS number in dotted format:16-bit user-defined number . For example, 65535.65535:1.
BGP route selection
BGP discards routes with unreachable NEXT_HOPs. If multiple routes to the same destination are available, BGP selects the optimal route in the following sequence:
1. The route with the highest Preferred_value.
2. The route with the highest LOCAL_PREF.
3. The route generated by the network command, the route redistributed by the import-route command, or the summary route in turn.
4. The route with the smallest AIGP attribute value.
5. The route with the shortest AS_PATH.
6. The IGP, EGP, or INCOMPLETE route in turn.
7. The route with the lowest MED value.
8. The route learned from EBGP, confederation EBGP, confederation IBGP, or IBGP in turn.
9. The route with the smallest IGP metric.
10. The route with the smallest recursion depth.
11. If a route received from an EBGP peer is the current optimal route, BGP does not change the optimal route when it receives routes from other EBGP peers.
12. The route advertised by the router with the smallest router ID.
If one of the routes is advertised by a route reflector, BGP compares the ORIGINATOR_ID of the route with the router IDs of other routers. Then, BGP selects the route with the smallest ID as the optimal route.
13. The route with the shortest CLUSTER_LIST.
14. The route advertised by the peer with the lowest IP address.
The CLUSTER_IDs of route reflectors form a CLUSTER_LIST. If a route reflector receives a route that contains its own CLUSTER ID in the CLUSTER_LIST, the router discards the route to avoid routing loops.
If load balancing is configured, the system selects available routes to implement load balancing.
BGP route advertisement rules
BGP follows these rules for route advertisement:
•
When multiple feasible routes to a destination exist, BGP advertises only the optimal route to its peers. If the advertise-rib-active command is configured, BGP advertises the optimal route in the IP routing table. If not, BGP advertises the optimal route in the BGP routing table.
265
•
BGP advertises only routes that it uses.
•
BGP advertises routes learned from an EBGP peer to all BGP peers, including both EBGP and
IBGP peers.
•
BGP advertises routes learned from an IBGP peer to EBGP peers, rather than other IBGP peers.
•
After establishing a session to a new BGP peer, BGP advertises all the routes matching the above rules to the peer. After that, BGP advertises only incremental updates to the peer.
BGP load balancing
BGP load balancing is applicable between EBGP peers, between IBGP peers, and between confederations.
BGP implements load balancing through route recursion and route selection.
BGP load balancing through route recursion
The next hop of a BGP route might not be directly connected. One of the reasons is that the next hop information exchanged between IBGP peers is not modified. The BGP router must find the directly connected next hop through IGP. The matching route with the direct next hop is called the recursive route. The process of finding a recursive route is route recursion.
If multiple recursive routes to the same destination are load balanced, BGP generates the same number of next hops to forward packets.
BGP load balancing based on route recursion is always enabled in the system.
BGP load balancing through route selection
IGP routing protocols, such as RIP and OSPF, can use route metrics as criteria to load balance between routes that have the same metric. BGP cannot load balance between routes by route metrics as an IGP protocol does, because BGP does not have a route computation algorithm.
BGP uses the following load balancing criteria to determine load balanced routes:
•
The routes have the same ORIGIN, LOCAL_PREF, AIGP, and MED attributes.
•
The routes meet the following requirements on the AS_PATH attribute:
If the balance as-path-neglect command is configured, the routes can have different
AS_PATH attributes.
If only the balance as-path-relax command is configured, the routes can have different AS_PATH attributes, but the length of the AS_PATH attributes must be the same.
If neither the balance as-path-neglect nor the balance as-path-relax command is configured, the routes must have the same AS_PATH attribute.
•
The next hops of the routes meet the following requirements on IGP metrics:
If the bestroute igp-metric-ignore command is not configured, the next hops of the routes must have the same IGP metric value.
If the bestroute igp-metric-ignore command is configured, the next hops of the routes can have different IGP metric values.
•
The routes have the same MPLS label assignment status (labeled or not labeled).
BGP does not use the route selection rules described in " BGP route selection " for load balancing.
As shown in Figure 68 , Router A and Router B are IBGP peers of Router C. Router C allows a
maximum number of two ECMP routes for load balancing.
Router D and Router E both advertise a route 9.0.0.0 to Router C. Router C installs the two routes to its routing table for load balancing if the routes meet the BGP load balancing criteria. After that,
Router C forwards to Router A and Router B a single route whose attributes are changed as follows:
266
•
AS_PATH attribute:
If the balance as-path-neglect and balance as-path-relax commands are not configured, the AS_PATH attribute does not change.
If the balance as-path-neglect or balance as-path-relax command is configured, the AS_PATH attribute is changed to the attribute of the optimal route.
•
The NEXT_HOP attribute is changed to the IP address of Router C.
•
Other attributes are changed to be the same as the optimal route.
Figure 68 Network diagram
Router A Router D
Router C
AS 200 AS 100
9.0.0.0/24
Router B Router E
Settlements for problems in large-scale BGP networks
You can use the following methods to facilitate management and improve route distribution efficiency on a large-scale BGP network.
Route summarization
Route summarization can reduce the BGP routing table size by advertising summary routes rather than more specific routes.
The system supports both manual and automatic route summarization. Manual route summarization allows you to determine the attribute of a summary route and whether to advertise more specific routes.
Route dampening
Route flapping (a route comes up and disappears in the routing table frequently) causes BGP to send many routing updates. It can consume too many resources and affect other operations.
In most cases, BGP runs in complex networks where route changes are more frequent. To solve the problem caused by route flapping, you can use BGP route dampening to suppress unstable routes.
BGP route dampening uses a penalty value to judge the stability of a route. The bigger the value, the less stable the route. Each time a route state changes from reachable to unreachable, or a reachable route's attribute changes, BGP adds a penalty value of 1000 to the route. When the penalty value of the route exceeds the suppress value, the route is suppressed and cannot become the optimal route.
When the penalty value reaches the upper limit, no penalty value is added.
267
If the suppressed route does not flap, its penalty value gradually decreases to half of the suppress value after a period of time. This period is called "Half-life." When the value decreases to the reusable threshold value, the route is usable again.
Figure 69 BGP route dampening
Penalty value
Suppress threshold
Reusable threshold
Suppression time
Time
Half-life
Peer group
You can organize BGP peers with the same attributes into a group to simplify their configurations.
When a peer joins the peer group, the peer obtains the same configuration as the peer group. If the configuration of the peer group is changed, the configuration of group members is changed.
Community
You can apply a community list or an extended community list to a routing policy for route control. For
more information, see " BGP path attributes ."
Route reflector
IBGP peers must be fully meshed to maintain connectivity. If n routers exist in an AS, the number of
IBGP connections is n(n-1)/2. If a large number of IBGP peers exist, large amounts of network and
CPU resources are consumed to maintain sessions.
Using route reflectors can solve this issue. In an AS, a router acts as a route reflector, and other routers act as clients connecting to the route reflector. The route reflector forwards routing information received from a client to other clients. In this way, all clients can receive routing information from one another without establishing BGP sessions.
establish BGP sessions to the route reflector and other non-clients.
268
Figure 70 Network diagram for a route reflector
IBGP
Route reflector
IBGP
Cluster
Client
IBGP
IBGP
IBGP
Non-client
IBGP
Client Client Non-client
AS 65000
The route reflector and clients form a cluster. Typically a cluster has one route reflector. The ID of the route reflector is the Cluster_ID. You can configure more than one route reflector in a cluster to
improve availability, as shown in Figure 71 . The configured route reflectors must have the same
Cluster_ID to avoid routing loops.
Figure 71 Network diagram for route reflectors
Route reflector1
IBGP
Route reflector2
Cluster
IBGP IBGP IBGP
Client Client
Client
AS 65000
When the BGP routers in an AS are fully meshed, route reflection is unnecessary because it consumes more bandwidth resources. You can use commands to disable route reflection instead of modifying network configuration or changing network topology.
After route reflection is disabled between clients, routes can still be reflected between a client and a non-client.
Confederation
Confederation is another method to manage growing IBGP connections in an AS. It splits an AS into multiple sub-ASs. In each sub-AS, IBGP peers are fully meshed. As shown in
intra-confederation EBGP connections are established between sub-ASs in AS 200.
269
Figure 72 Confederation network diagram
AS 65002 AS 65003
EBGP EBGP
EBGP
AS 100 IBGP
IBGP
IBGP
AS 65004
AS 200
A non-confederation BGP speaker does not need to know sub-ASs in the confederation. To the BGP speaker, the confederation is one AS and the confederation ID is the AS number. In the above figure,
AS 200 is the confederation ID.
Confederation has a deficiency. When you change an AS into a confederation, you must reconfigure the routers, and the topology will be changed.
In large-scale BGP networks, you can use both route reflector and confederation.
MP-BGP
Supported address families
BGP-4 can only advertise IPv4 unicast routing information. Multiprotocol Extensions for BGP-4
(MP-BGP) can advertise routing information for the following address families:
•
IPv6 unicast address family.
•
VPNv4 address family and VPNv6 address family.
For more information, see MPLS Configuration Guide .
•
Labeled IPv4 unicast address family and IPv6 unicast address family.
MP-BGP advertises IPv4 unicast/IPv6 unicast routes and MPLS labels assigned for the routes.
Labeled IPv4 unicast routes apply to inter-AS Option C for MPLS L3VPN. Labeled IPv6 unicast routes apply to 6PE and inter-AS Option C for MPLS L3VPN. For more information about inter-AS Option C, see MPLS Configuration Guide .
•
EVPN address family.
MP-BGP advertises EVPN routes to implement automatic VTEP discovery, VXLAN tunnel establishment and assignment, and MAC and ARP information advertisement. For more information about EVPN, see EVPN Configuration Guide .
MP-BGP extended attributes
Prefixes and next hops are key routing information. BGP-4 uses UPDATE messages to carry the following information:
•
Feasible route prefixes in the Network Layer Reachability Information (NLRI) field.
•
Unfeasible route prefixes in the withdrawn routes field.
270
•
Next hops in the NEXT_HOP attribute.
BGP-4 cannot carry routing information for multiple network layer protocols.
To support multiple network layer protocols, MP-BGP defines the following path attributes:
•
MP_REACH_NLRI —Carries feasible route prefixes and next hops for multiple network layer protocols.
•
MP_UNREACH_NLRI —Carries unfeasible route prefixes for multiple network layer protocols.
MP-BGP uses these two attributes to advertise feasible and unfeasible routes for different network layer protocols. BGP speakers not supporting MP-BGP ignore updates containing these attributes and do not forward them to its peers.
Address family
MP-BGP uses address families and subsequent address families to identify different network layer protocols for routes contained in the MP_REACH_NLRI and MP_UNREACH_NLRI attributes. For example, an Address Family Identifier (AFI) of 2 and a Subsequent Address Family Identifier (SAFI) of 1 identify IPv6 unicast routing information carried in the MP_REACH_NLRI attribute. For address family values, see RFC 1700.
Exchanging IPv4 and IPv6 routes in both IPv4 and IPv6 address families
MP-BGP supports IPv4 route exchange between IPv6 peers and IPv6 route exchange between IPv4 peers as follows:
•
When the next hop of an IPv6 route is an IPv4 address, MP-BGP maps the IPv4 address to an
IPv6 address encapsulated in the NEXT_HOP attribute of update messages. In this scenario, you must specify a routing policy to change the next hop of the IPv6 route to the IPv6 address of the peer.
•
When the next hop of an IPv4 route is an IPv6 address, BGP negotiates the extended next hop encoding capability with its peer. Then, BGP encapsulates the IPv4 NLRI in the
MP_REACH_NLRI attribute of update messages. In this scenario, you must specify a routing policy to change the next hop of the IPv4 route to the IPv4 address of the peer.
Figure 73 Exchanging IPv4 and IPv6 routes in both IPv4 and IPv6 address families
Device B
Port A
10.1.1.1/24
10::1/64
Port B
10.1.1.2/24
10::2/64
Device C
Device A Device D
As shown in Figure 73 , an IPv6 BGP peer relationship is established between Device A and Device B,
between Device B and Device C, and between Device C and Device D. An IPv4 BGP peer relationship is established between Device A and Device B and between Device C and Device D.
Device A and Device D can learn both IPv4 and IPv6 routes from each other and traffic is forwarded correctly in both IPv4 and IPv6 address families. For Device C to correctly receive IPv4 routes using the IPv6 address of Device B as the next hop, configure a routing policy on Device C. Use the routing policy to change the next hop of these routes to the IPv4 address of Device B.
BGP multi-instance
A BGP router can run multiple BGP processes. Each BGP process corresponds to a BGP instance.
BGP maintains an independent routing table for each BGP instance.
271
BGP configuration views
BGP uses different views to manage routing information for different BGP instances, VPN instances, and address families. Most BGP commands are available in all BGP views. BGP supports multiple
VPN instances by establishing a separate routing table for each VPN instance.
Table 23 describes different BGP configuration views.
Table 20 BGP configuration views
View names
BGP instance view
Ways to enter the views Remarks
You can create a BGP instance and enter its view by specifying the instance keyword in the bgp command.
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc]
Configurations in this view apply to all public address families for the specified BGP instance. Some configurations (such as confederation, GR, and logging configurations) also apply to the address families of VPN instances.
BGP IPv4 unicast address family view
BGP IPv6 unicast address family view
BGP VPNv4 address family view
BGP VPNv6 address family view
BGP EVPN address family view
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] address-family ipv4 unicast
Configurations in this view apply to public IPv4 unicast routes and peers of the specified BGP instance.
[Sysname-bgp-abc-ipv4]
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] address-family ipv6 unicast
Configurations in this view apply to public IPv6 unicast routes and peers of the specified BGP instance.
[Sysname-bgp-abc-ipv6]
<Sysname> system-view
[Sysname] bgp 100 instance abc
Configurations in this view apply to
VPNv4 routes and peers of the specified BGP instance.
[Sysname-bgp-abc] address-family vpnv4
[Sysname-bgp-abc-vpnv4]
For more information about BGP
VPNv4 address family view, see
MPLS Configuration Guide .
<Sysname> system-view
[Sysname] bgp 100 instance abc
Configurations in this view apply to
VPNv6 routes and peers of the specified BGP instance.
[Sysname-bgp-abc] address-family vpnv6
[Sysname-bgp-abc-vpnv6]
For more information about BGP
VPNv6 address family view, see
MPLS Configuration Guide .
<Sysname> system-view
[Sysname] bgp 100 instance abc
Configurations in this view apply to
EVPN routes and peers of the specified BGP instance.
[Sysname-bgp-abc] address-family l2vpn evpn
[Sysname-bgp-abc-evpn]
For more information about BGP
EVPN address family view, see
EVPN Configuration Guide .
272
View names
BGP-VPN instance view
Ways to enter the views Remarks
<Sysname> system-view
[Sysname] bgp 100 instance abc
Configurations in this view apply to all address families in the specified
VPN instance of the specified BGP instance.
[Sysname-bgp-abc] ip vpn-instance vpn1
[Sysname-bgp-abc-vpn1]
For more information about VPN instances, see MPLS L3VPN configuration in MPLS Configuration
Guide .
BGP-VPN IPv4 unicast address family view
BGP-VPN IPv6 unicast address family view
BGP-VPN VPNv4 address family view
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] ip vpn-instance vpn1
Configurations in this view apply to
IPv4 unicast routes and peers in the specified VPN instance of the specified BGP instance.
[Sysname-bgp-abc-vpn1] address-family ipv4 unicast
[Sysname-bgp-abc-ipv4-vpn1]
For more information about VPN instances, see MPLS L3VPN configuration in MPLS Configuration
Guide .
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] ip vpn-instance vpn1
Configurations in this view apply to
IPv6 unicast routes and peers in the specified VPN instance of the specified BGP instance.
[Sysname-bgp-abc-vpn1] address-family ipv6 unicast
[Sysname-bgp-abc-ipv6-vpn1]
For more information about VPN instances, see MPLS L3VPN configuration in MPLS Configuration
Guide .
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] ip vpn-instance vpn1
Configurations in this view apply to
VPNv4 routes and peers in the specified VPN instance of the specified BGP instance.
[Sysname-bgp-abc-vpn1] address-family vpnv4
[Sysname-bgp-abc-vpnv4-vpn1]
For more information about
BGP-VPN VPNv4 address family view, see MPLS Configuration
Guide .
BGP LS address family view
BGP IPv4 RT filter address family view
<Sysname> system-view
[Sysname] bgp 100 instance abc
[Sysname-bgp-abc] address-family link-state
Configurations in this view apply to
LS messages and peers of the specified BGP instance.
[Sysname-bgp-abc-ls]
<Sysname> system-view
[Sysname] bgp 100 instance abc
Configurations in this view apply to
IPv4 RT filter routes and peers of the specified BGP instance.
[Sysname-bgp-abc] address-family ipv4 rtfilter
[Sysname-bgp-abc-rtf-ipv4]
For more information about BGP
IPv4 RT filter address family view, see MPLS L3VPN Configuration
Guide .
Protocols and standards
•
RFC 1700, ASSIGNED NUMBERS
•
RFC 1997, BGP Communities Attribute
•
RFC 2439, BGP Route Flap Damping
•
RFC 2545, Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing
•
RFC 2918, Route Refresh Capability for BGP-4
273
•
RFC 3107, Carrying Label Information in BGP-4
•
RFC 4271, A Border Gateway Protocol 4 (BGP-4)
•
RFC 4275, BGP-4 MIB Implementation Survey
•
RFC 4277, Experience with the BGP-4 Protocol
•
RFC 4360, BGP Extended Communities Attribute
•
RFC 4364, BGP/MPLS IP Virtual Private Networks (VPNs)
•
RFC 4382, MPLS/BGP Layer 3 Virtual Private Network (VPN) Management
•
RFC 4451, BGP MULTI_EXIT_DISC (MED) Consideration
•
RFC 4456, BGP Route Reflection: An Alternative to Full Mesh Internal BGP
•
RFC 4486, Subcodes for BGP Cease Notification Message
•
RFC 4659, BGP-MPLS IP Virtual Private Network (VPN) Extension for IPv6 VPN
•
RFC 4684, Constrained Route Distribution for Border Gateway Protocol/MultiProtocol Label
Switching (BGP/MPLS) Internet Protocol (IP) Virtual Private Networks (VPNs)
•
RFC 4724, Graceful Restart Mechanism for BGP
•
RFC 4760, Multiprotocol Extensions for BGP-4
•
RFC 4781, Graceful Restart Mechanism for BGP with MPLS
•
RFC 5004, Avoid BGP Best Path Transitions from One External to Another
•
RFC 5065, Autonomous System Confederations for BGP
•
RFC 5082, The Generalized TTL Security Mechanism (GTSM)
•
RFC 5291, Outbound Route Filtering Capability for BGP-4
•
RFC 5292, Address-Prefix-Based Outbound Route Filter for BGP-4
•
RFC 5492, Capabilities Advertisement with BGP-4
•
RFC 5549, Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop
•
RFC 5668, 4-Octet AS Specific BGP Extended Community
•
RFC 6037, Cisco Systems' Solution for Multicast in BGP MPLS IP VPNs
•
RFC 6198, Requirements for the Graceful Shutdown of BGP Sessions
•
RFC 6368, Internal BGP as the Provider/Customer Edge Protocol for BGP/MPLS IP
•
RFC 6513, Multicast in MPLS/BGP IP VPNs
•
RFC 6514, BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs
•
RFC 6515, IPv4 and IPv6 Infrastructure Addresses in BGP Updates for Multicast VPN
•
RFC 6624, Layer 2 Virtual Private Networks Using BGP for Auto-Discovery and Signaling
•
RFC 6793, BGP Support for Four-Octet Autonomous System (AS) Number Space
•
RFC 7432, BGP MPLS-Based Ethernet VPN
•
RFC 7752, North-Bound Distribution of Link-State and Traffic Engineering (TE) Information
Using BGP
•
RFC 7854, BGP Monitoring Protocol (BMP)
•
RFC 7911, Advertisement of Multiple Paths in BGP
274
Building basic BGP networks
Restrictions and guidelines: BGP configuration
You can create multiple public address families for a BGP instance. However, each public address family (except for public IPv4 unicast, IPv6 unicast, VPNv4, and VPNv6 address families) can belong to only one BGP instance.
You can create multiple VPN instances for a BGP instance, and each VPN instance can have multiple address families. A VPN instance can belong to only one BGP instance.
You cannot specify the same peer for the same address family of different BGP instances.
Different BGP instances can have the same AS number but cannot have the same name.
Basic BGP network configuration tasks at a glance (IPv4 unicast)
To build basic BGP networks for the IPv4 unicast address family, perform the following tasks:
1.
a.
b.
c.
d.
Configuring an IBGP peer group
Configure BGP peer groups on large-scale BGP networks for easy configuration and maintenance.
e.
Configuring an EBGP peer group
Configure BGP peer groups on large-scale BGP networks for easy configuration and maintenance.
f.
(Optional.) Specifying the source address of TCP connections
g.
(Optional.) Setting the TCP MSS
2.
Controlling BGP route generation
Choose the following tasks as needed:
(Optional.) Configuring BGP route summarization
(Optional.) Advertising a default route to a peer or peer group
3.
(Optional.) Controlling BGP route advertisement
Advertising optimal routes in the IP routing table
Enabling prioritized withdrawal of the default route
Enabling prioritized withdrawal of specific routes
Configuring BGP route distribution filtering policies
Enabling first-AS-number check for EBGP routes before route advertisement
Setting the BGP route sending rate
Configuring BGP route update delay
Configuring a startup policy for BGP route updates
275
Configuring the BGP update message sending parameters
4.
(Optional.) Controlling BGP route reception
Limiting routes received from a peer or peer group
Configuring BGP route reception filtering policies
Configuring the link bandwidth attribute
5.
(Optional.) Configuring BGP timers
Configuring the keepalive interval and hold time
Setting the session retry timer
Setting an update delay for local MPLS labels
6.
(Optional.) Configuring BGP logging and notifications
Enabling logging for session state changes
Enabling logging for BGP route flapping
Configuring BGP network management
Basic BGP network configuration tasks at a glance (IPv6 unicast)
To build basic BGP networks for the IPv6 unicast address family, perform the following tasks:
1.
a.
b.
c.
d.
Configuring an IBGP peer group
Configure BGP peer groups on large-scale BGP networks for easy configuration and maintenance.
e.
Configuring an EBGP peer group
Configure BGP peer groups on large-scale BGP networks for easy configuration and maintenance.
f.
(Optional.) Specifying the source address of TCP connections
g.
(Optional.) Setting the TCP MSS
2.
Controlling BGP route generation
Choose the following tasks as needed:
(Optional.) Configuring BGP route summarization
(Optional.) Advertising a default route to a peer or peer group
3.
(Optional.) Controlling BGP route advertisement
Advertising optimal routes in the IP routing table
Enabling prioritized withdrawal of specific routes
Configuring BGP route distribution filtering policies
Configuring BGP route distribution filtering policies
Enabling first-AS-number check for EBGP routes before route advertisement
Setting the BGP route sending rate
276
Configuring BGP route update delay
Configuring a startup policy for BGP route updates
Configuring the BGP update message sending parameters
4.
(Optional.) Controlling BGP route reception
Limiting routes received from a peer or peer group
Configuring BGP route reception filtering policies
Configuring the link bandwidth attribute
5.
(Optional.) Configuring BGP timers
Configuring the keepalive interval and hold time
Setting the session retry timer
Setting an update delay for local MPLS labels
6.
(Optional.) Configuring BGP logging and notifications
Enabling logging for session state changes
Enabling logging for BGP route flapping
Configuring BGP network management
Configuring basic BGP
Enabling BGP
Restrictions and guidelines
A router ID is the unique identifier of a BGP router in an AS.
•
To ensure the uniqueness of a router ID and enhance availability, specify in BGP instance view the IP address of a local loopback interface as the router ID. Different BGP instances can have the same router ID.
•
If no router ID is specified in BGP instance view, the global router ID is used.
•
To modify a non-zero router ID of a BGP instance , use the router-id command in BGP instance view, rather than the router id command in system view.
•
If you specify a router ID in BGP instance view and then remove the interface that owns the router ID, the router does not select a new router ID. To select a new router ID, use the undo router-id command in BGP instance view.
Procedure
1. Enter system view. system-view
2. Configure a global router ID.
router id router-id
By default, no global router ID is configured.
If no global router ID is configured, the following rules apply:
If loopback interfaces configured with an IP address exist, BGP uses the highest loopback interface IP address as the router ID.
If no loopback interface IP address is available, BGP uses the highest physical interface IP address as the route ID regardless of the interface status.
3. Enable BGP and enter BGP instance view.
bgp as-number [ instance instance-name ]
277
By default, BGP is disabled and no BGP instances exist.
4. (Optional.) Configure a router ID for the BGP instance.
router-id router-id
By default, no router ID is configured for a BGP instance, and the BGP instance uses the global router ID configured by the router-id command in system view.
5. (Optional.) Enter BGP-VPN instance view.
ip vpn-instance vpn-instance-name
The specified VPN instance must have been created and have an RD.
6. (Optional.) Configure a router ID for the BGP VPN instance.
router-id { router-id | auto-select }
By default, no router ID is configured for a BGP VPN instance.
The BGP VPN instance uses the router ID configured in BGP instance view. If no router ID is configured in BGP instance view, the BGP VPN instance uses the global router ID configured in system view.
Configuring a BGP peer
Restrictions and guidelines
A BGP peer at an IPv6 link-local address must be directly connected to the local router. On the local router, you must use the peer connect-interface command to specify the interface directly connected to the BGP peer as the source interface of TCP connections.
To exchange IPv4 routes with an IPv6 peer or exchange IPv6 routes with an IPv4 peer, you must configure a routing policy to perform the following tasks:
•
Change the next hop of IPv4 routes received from the IPv6 peer to the IPv4 address of the interface that connects the IPv6 peer to the local router.
•
Change the next hop of IPv6 routes received from the IPv4 peer to the IPv6 address of the interface that connects the IPv4 peer to the local router.
Procedure (Exchanging IPv4 unicast routes with IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IPv4 BGP peer and specify its AS number.
peer ipv4-address as-number as-number
4. (Optional.) Configure a description for a peer. peer ipv4-address description text
By default, no description is configured for a peer.
5. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
6. Enable the router to exchange IPv4 unicast routing information with the specified peer.
278
peer ipv4-address enable
By default, the router cannot exchange IPv4 unicast routing information with the peer.
Procedure (Exchanging IPv6 unicast routes with IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IPv4 BGP peer and specify its AS number.
peer ipv4-address as-number as-number
4. (Optional.) Configure a description for the peer. peer ipv4-address description text
By default, no description is configured for a peer.
5. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
6. Enable BGP to exchange IPv6 unicast routing information with the IPv4 peer.
peer ipv4-address enable
By default, BGP cannot exchange IPv6 unicast routing information with an IPv4 peer.
7. Use a routing policy to modify the next hop of routes received from the IPv4 peer.
peer ipv4-address route-policy route-policy-name import
Procedure (Exchanging IPv6 unicast routes with IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IPv6 BGP peer and specify its AS number.
peer ipv6-address as-number as-number
4. (Optional.) Configure a description for a peer.
peer ipv6-address description text
By default, no description is configured for a peer.
5. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
6. Enable the router to exchange IPv6 unicast routing information with the specified peer.
peer ipv6-address enable
By default, the router cannot exchange IPv6 unicast routing information with the peer.
279
Procedure (Exchanging IPv4 unicast routes with IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IPv6 BGP peer and specify its AS number.
peer ipv6-address as-number as-number
4. (Optional.) Configure a description for the peer. peer ipv6-address description text
By default, no description is configured for a peer.
5. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
6. Enable BGP to exchange IPv4 unicast routing information with the IPv6 peer.
peer ipv6-address enable
By default, BGP cannot exchange IPv4 unicast routing information with an IPv6 peer.
7. Use a routing policy to modify the next hop of routes received from the IPv6 peer.
peer ipv6-address route-policy route-policy-name import
Configuring dynamic BGP peers
About this task
This feature enables BGP to establish dynamic BGP peer relationships with devices in a network.
BGP accepts connection requests from the network but it does not initiate connection requests to the network.
After a device in the network initiates a connection request, BGP establishes a dynamic peer relationship with the device.
If multiple BGP peers reside in the same network, you can use this feature to simplify BGP peer configuration.
Restrictions and guidelines
For a remote device to establish a peer relationship with the local device, you must specify the IP address of the local device on the remote device.
A BGP peer at an IPv6 link-local address must be directly connected to the local router. On the local router, you must use the peer connect-interface command to specify the interface directly connected to the BGP peer as the source interface of TCP connections.
To exchange IPv4 routes with an IPv6 peer or exchange IPv6 routes with an IPv4 peer, you must configure a routing policy to perform the following tasks:
•
Change the next hop of IPv4 routes received from the IPv6 peer to the IPv4 address of the interface that connects the IPv6 peer to the local router.
•
Change the next hop of IPv6 routes received from the IPv4 peer to the IPv6 address of the interface that connects the IPv4 peer to the local router.
280
Procedure (Exchanging IPv4 unicast routes with dynamic IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify devices in a network as dynamic BGP peers and specify an AS number for the peers.
peer ipv4-address mask-length as-number as-number
4. (Optional.) Configure a description for dynamic BGP peers. peer ipv4-address mask-length description text
By default, no description is configured for dynamic BGP peers.
5. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
6. Enable BGP to exchange IPv4 unicast routing information with dynamic BGP peers in the specified network.
peer ipv4-address mask-length enable
By default, BGP cannot exchange IPv4 unicast routing information with dynamic BGP peers.
Procedure (Exchanging IPv6 unicast routes with dynamic IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify devices in an IPv4 network as dynamic IPv4 BGP peers and specify an AS number for the peers.
peer ipv4-address mask-length as-number as-number
4. (Optional.) Configure a description for the peer. peer ipv4-address mask-length description text
By default, no description is configured for dynamic peers.
5. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
6. Enable BGP to exchange IPv6 unicast routing information with the dynamic IPv4 peers.
peer ipv4-address mask-length enable
By default, BGP cannot exchange IPv6 unicast routing information with dynamic IPv4 peers.
7. Use a routing policy to modify the next hop of routes received from the dynamic IPv4 peers.
peer ipv4-address mask-length route-policy route-policy-name import
281
Procedure (Exchanging IPv6 unicast routes with dynamic IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify devices in a network as dynamic BGP peers and specify an AS number for the peers.
peer ipv6-address prefix-length as-number as-number
4. (Optional.) Configure a description for dynamic BGP peers. peer ipv6-address prefix-length description text
By default, no description is configured for dynamic BGP peers.
5. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
6. Enable BGP to exchange IPv6 unicast routing information with dynamic BGP peers in the specified network.
peer ipv6-address prefix-length enable
By default, BGP cannot exchange IPv6 unicast routing information with dynamic BGP peers.
Procedure (Exchanging IPv4 unicast routes with dynamic IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify devices in an IPv6 network as dynamic IPv6 BGP peers and specify an AS number for the peers.
peer ipv6-address prefix-length as-number as-number
4. (Optional.) Configure a description for the dynamic IPv6 peers. peer ipv6-address prefix-length description text
By default, no description is configured for dynamic peers.
5. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
6. Enable BGP to exchange IPv4 unicast routing information with dynamic IPv6 peers.
peer ipv6-address prefix-length enable
By default, BGP cannot exchange IPv4 unicast routing information with dynamic IPv6 peers.
7. Use a routing policy to modify the next hop of routes received from the dynamic IPv6 peers.
peer ipv6-address mask-length route-policy route-policy-name import
282
Configuring an IBGP peer group
About this task
A peer group is an IBGP peer group if peers in it belong to the same AS as the local router.
After you create an IBGP peer group and then add a peer into it, the system creates the peer in BGP instance view and specifies the local AS number for the peer.
Restrictions and guidelines
A BGP peer at an IPv6 link-local address must be directly connected to the local router. On the local router, you must use the peer connect-interface command to specify the interface directly connected to the BGP peer as the source interface of TCP connections.
To exchange IPv4 routes with an IPv6 peer or exchange IPv6 routes with an IPv4 peer, you must configure a routing policy to perform the following tasks:
•
Change the next hop of IPv4 routes received from the IPv6 peer to the IPv4 address of the interface that connects the IPv6 peer to the local router.
•
Change the next hop of IPv6 routes received from the IPv4 peer to the IPv6 address of the interface that connects the IPv4 peer to the local router.
If you configure a BGP setting at both the peer group and the peer level, the most recent configuration takes effect on the peer.
Procedure (Exchanging IPv4 unicast routes with IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IBGP peer group.
group group-name [ internal ]
4. Add a peer into the IBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the local AS number.
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
6. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
7. Enable the router to exchange IPv4 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv4 unicast routing information with the peers.
283
Procedure (Exchanging IPv6 unicast routes with IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IBGP peer group. group group-name [ internal ]
4. Add an IPv4 peer into the IBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the local AS number.
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
6. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
7. Enable BGP to exchange IPv6 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv6 unicast routing information with peers in a peer group.
8. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Procedure (Exchanging IPv6 unicast routes with IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IBGP peer group.
group group-name [ internal ]
4. Add a peer into the IBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the local AS number.
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
284
6. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
7. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Procedure (Exchanging IPv4 unicast routes with IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an IBGP peer group. group group-name [ internal ]
4. Add an IPv6 peer into the IBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the local AS number.
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
6. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
7. Enable BGP to exchange IPv4 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv4 unicast routing information with peers in a peer group.
8. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group
About this task
A peer group is an EBGP peer group if peers in it belong to different ASs.
If peers in an EBGP group belong to the same external AS, the EBGP peer group is a pure EBGP peer group. If not, it is a mixed EBGP peer group.
Restrictions and guidelines
Use one of the following methods to configure an EBGP peer group:
•
Method 1 —Create an EBGP peer group, specify its AS number, and add peers into it. All the added peers have the same AS number. All peers in the peer group have the same AS number as the peer group. You can specify an AS number for a peer before adding it into the peer group.
The AS number must be the same as that of the peer group.
285
•
Method 2 —Create an EBGP peer group, specify an AS number for a peer, and add the peer into the peer group. Peers added in the group can have different AS numbers.
•
Method 3 —Create an EBGP peer group and add a peer with an AS number into it. Peers added in the group can have different AS numbers.
To exchange IPv4 routes with an IPv6 peer or exchange IPv6 routes with an IPv4 peer, you must configure a routing policy to perform the following tasks:
•
Change the next hop of IPv4 routes received from the IPv6 peer to the IPv4 address of the interface that connects the IPv6 peer to the local router.
•
Change the next hop of IPv6 routes received from the IPv4 peer to the IPv6 address of the interface that connects the IPv4 peer to the local router.
If you configure a BGP setting at both the peer group and the peer level, the most recent configuration takes effect on the peer.
Configuring an EBGP peer group by using Method 1 (Exchanging IPv4 unicast routes with
IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Specify the AS number of the group.
peer group-name as-number as-number
By default, no AS number is specified.
If a peer group contains peers, you cannot remove or change its AS number.
5. Add a peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer
group-name as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
7. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
8. Enable the router to exchange IPv4 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv4 unicast routing information with the peers.
286
Configuring an EBGP peer group by using Method 2 (Exchanging IPv4 unicast routes with
IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Create an IPv4 BGP peer and specify its AS number. peer ipv4-address [ mask-length ] as-number as-number
5. Add the peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer ipv4-address [ mask-length ] as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
7. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
8. Enable the router to exchange IPv4 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Configuring an EBGP peer group by using Method 3 (Exchanging IPv4 unicast routes with
IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Add a peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name as-number as-number
5. (Optional.) Configure a description for the peer group.
287
peer group-name description text
By default, no description is configured for the peer group.
6. Create the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
7. Enable the router to exchange IPv4 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Configuring an EBGP peer group by using Method 1 (Exchanging IPv6 unicast routes with
IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group. group group-name external
4. Specify an AS number for the peer group. peer group-name as-number as-number
By default, no AS number is specified for a peer group.
If a peer group contains peers, you cannot remove or change its AS number.
5. Add an IPv4 peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer
group-name as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
7. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
8. Enable BGP to exchange IPv6 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv6 unicast routing information with peers in a peer group.
9. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group by using Method 2 (Exchanging IPv6 unicast routes with
IPv4 peers)
1. Enter system view. system-view
288
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group. group group-name external
4. Create an IPv4 BGP peer and specify its AS number. peer ipv4-address [ mask-length ] as-number as-number
5. Add the IPv4 peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer ipv4-address [ mask-length ] as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
7. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
8. Enable BGP to exchange IPv6 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv6 unicast routing information with peers in a peer group.
9. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group by using Method 3 (Exchanging IPv6 unicast routes with
IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group. group group-name external
4. Add an IPv4 peer into the EBGP peer group. peer ipv4-address [ mask-length ] group group-name as-number as-number
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
6. Create the BGP IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
289
7. Enable BGP to exchange IPv6 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv6 unicast routing information with peers in a peer group.
8. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group by using Method 1 (Exchanging IPv6 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Specify the AS number of the group.
peer group-name as-number as-number
By default, no AS number is specified.
If a peer group contains peers, you cannot remove or change its AS number.
5. Add a peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer
group-name as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
7. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
8. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Configuring an EBGP peer group by using Method 2 (Exchanging IPv6 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
290
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Create an IPv6 BGP peer and specify its AS number. peer ipv6-address [ prefix-length ] as-number as-number
5. Add the peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer ipv6-address [ prefix-length ] as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
7. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
8. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
peer group-name enable
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Configuring an EBGP peer group by using Method 3 (Exchanging IPv6 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
group group-name external
4. Add a peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name as-number as-number
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for the peer group.
6. Create the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
7. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
peer group-name enable
291
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Configuring an EBGP peer group by using Method 1 (Exchanging IPv4 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group. group group-name external
4. Specify an AS number for the peer group. peer group-name as-number as-number
By default, no AS number is specified for a peer group.
If a peer group contains peers, you cannot remove or change its AS number.
5. Add an IPv6 peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer
group-name as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
7. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
8. Enable BGP to exchange IPv4 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv4 unicast routing information with peers in a peer group.
9. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group by using Method 2 (Exchanging IPv4 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group.
292
group group-name external
4. Create an IPv6 BGP peer and specify its AS number. peer ipv6-address [ prefix-length ] as-number as-number
5. Add the IPv6 peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
The as-number as-number option must specify the same AS number as the peer ipv6-address [ prefix-length ] as-number as-number command.
6. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
7. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
8. Enable BGP to exchange IPv4 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv4 unicast routing information with peers in a peer group.
9. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
Configuring an EBGP peer group by using Method 3 (Exchanging IPv4 unicast routes with
IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create an EBGP peer group. group group-name external
4. Add an IPv6 peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name as-number as-number
5. (Optional.) Configure a description for the peer group. peer group-name description text
By default, no description is configured for a peer group.
6. Create the BGP IPv4 unicast address family and enter its view. address-family ipv4 [ unicast ]
7. Enable BGP to exchange IPv4 unicast routing information with peers in the peer group.
peer group-name enable
By default, BGP cannot exchange IPv4 unicast routing information with peers in a peer group.
8. Use a routing policy to modify the next hop of routes received from peers in the peer group.
peer group-name route-policy route-policy-name import
293
Specifying the source address of TCP connections
About this task
BGP uses TCP as the transport layer protocol. Perform this task in the following scenarios to specify the source address or source interface of TCP connections to a peer or peer group:
•
The peer's IPv4/IPv6 address does not belong to the interface directly connected to the local router. To ensure successful TCP connection establishment, use one of the following methods:
Specify the interface to which the IPv4/IPv6 address belongs as the source interface on the peer.
Specify the IPv4/IPv6 address of the interface directly connected to the local router as the source address on the peer.
•
A BGP peer at an IPv6 link-local address must be directly connected to the local router. On the local router, you must use the peer connect-interface command to specify the interface directly connected to the BGP peer as the source interface of TCP connections.
•
On a BGP router that has multiple links to a peer, the source interface for TCP connection changes because the primary source interface fails. To avoid this problem, specify a loopback interface as the source interface or specify the IP address of a loopback interface as the source address.
•
You want to establish multiple BGP sessions to a router. In this case, BGP might fail to determine the source address for each TCP connection based on the optimal route to the peer.
To prevent this problem, use one of the following methods:
If the BGP sessions use IP addresses of different interfaces, specify a source interface or source address for each session.
If the BGP sessions use different IP addresses of the same interface, specify a source address for each session.
Restrictions and guidelines
BGP immediately tears down the session to an IBGP peer or peer group when the following conditions exist:
•
The source interface of TCP connections to the IBGP peer or peer group is a physical interface.
•
The source interface fails and the link to the IBGP peer or peer group goes down.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify the source address or source interface of TCP connections to a peer or peer group.
Specify the source address of TCP connections to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } source-address source-ipv4-address
Specify the source interface of TCP connections to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } connect-interface interface-type interface-number
294
By default, BGP uses the primary IPv4 address of the output interface in the optimal route to a peer or peer group as the source address of TCP connections to the peer or peer group.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Specify the source IPv6 address or source interface of TCP connections to a peer or peer group.
Specify the source IPv6 address of TCP connections to a peer or peer group.
peer { group-name | ipv6-address [ prefix-length ] } source-address source-ipv6-address
Specify the source interface of TCP connections to a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } connect-interface interface-type interface-number
By default, BGP uses the IPv6 address of the output interface in the optimal route to the BGP peer or peer group as the source address of TCP connections to the peer or peer group.
Setting the TCP MSS
About this task
During the packet exchange between BGP peers that are not directly connected, frequent packet fragmentation will occur if the link layer MTUs of the traversed networks are different. To resolve this issue, perform this task to set the maximum segment size (MSS) for TCP packets exchanged with a peer or peer group. Then, TCP packets to the peer or peer group will not be fragmented before reaching the destination, which improves the network performance.
Restrictions and guidelines
This feature takes effect only on BGP sessions established or re-established after the feature is configured.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set the MSS for TCP packets exchanged with an IPv4 peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } tcp-mss mss-value
By default, the MSS for TCP packets exchanged with an IPv4 peer or peer group is not set.
295
Controlling BGP route generation
Injecting a local network
About this task
Perform this task to inject a network in the local routing table to the BGP routing table, so BGP can advertise the network to BGP peers. The ORIGIN attribute of BGP routes advertised in this way is
IGP. You can also use a routing policy to control route advertisement.
The specified network must be available and active in the local IP routing table.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure BGP to advertise a local network. network ipv4-address [ mask-length | mask ] [ route-policy route-policy-name ]
By default, BGP does not advertise local networks.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure BGP to advertise a local network. network ipv6-address prefix-length [ route-policy route-policy-name ]
By default, BGP does not advertise local networks.
296
Redistributing IGP routes
About this task
Perform this task to configure route redistribution from an IGP to BGP.
By default, BGP does not redistribute default IGP routes. You can use the default-route imported command to redistribute default IGP routes into the BGP routing table.
The ORIGIN attribute of BGP routes redistributed from IGPs is INCOMPLETE.
Only active routes can be redistributed. To view route state information, use the display ip routing-table protocol or display ipv6 routing-table protocol command. For more information about the commands, see Layer 3—IP Routing Command Reference .
If you execute the import-route command multiple times for an IGP process, the most recent configuration takes effect. To redistribute more routes from an IGP process without overwriting the routes redistributed before, use the import-route-append command.
When you execute both the import-route and import-route-append commands for an IGP process, the commands take effect as follows:
•
A route is redistributed as long as it matches the criteria of either command.
•
If a route matches the criteria of both commands, the route is redistributed, and the apply clauses in the routing policies specified in the two commands take effect as follows:
If the apply clauses do not conflict, all apply clauses take effect.
If conflicts occur between the apply clauses, only the apply clauses in the import-route-append command take effect.
•
The MED value specified by the import-route-append command takes precedence over that specified by the import-route command.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable route redistribution from the specified IGP into BGP.
Redistribute IS-IS, OSPF, or RIP routes. import-route { isis | ospf | rip } [ { process-id | all-processes }
[ allow-direct | med med-value | route-policy route-policy-name ] * ]
Redistribute direct or static routes. import-route { direct | static } [ med med-value | route-policy route-policy-name ] *
By default, BGP does not redistribute IGP routes.
297
4. (Optional.) Redistribute routes from an IGP without overwriting the routes redistributed by the import-route command.
Redistribute IS-IS, OSPF, or RIP routes. import-route-append { isis | ospf | rip } [ { process-id |
all-processes } [ allow-direct | med med-value | route-policy route-policy-name ] * ]
Redistribute direct or static routes. import-route-append { direct | static } [ med med-value |
route-policy route-policy-name ] *
By default, BGP does not redistribute IGP routes.
5. (Optional.) Enable default route redistribution into BGP. default-route imported
By default, BGP does not redistribute default routes.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable route redistribution from the specified IGP into BGP.
Redistribute IPv6 IS-IS, OSPFv3, or RIPng routes. import-route { isisv6 | ospfv3 | ripng } [ { process-id |
all-processes } [ allow-direct | med med-value | route-policy route-policy-name ] * ]
Redistribute direct or static routes. import-route { direct | static } [ med med-value | route-policy route-policy-name ]
By default, BGP does not redistribute IGP routes.
4. (Optional.) Redistribute routes from an IGP without overwriting the routes redistributed by the import-route command.
Redistribute IPv6 IS-IS, OSPFv3, or RIPng routes. import-route-append { isisv6 | ospfv3 | ripng } [ { process-id |
all-processes } [ allow-direct | med med-value | route-policy route-policy-name ] * ]
Redistribute direct or static routes. import-route-append { direct | static } [ med med-value |
route-policy route-policy-name ] *
By default, BGP does not redistribute IGP routes.
5. (Optional.) Enable default route redistribution into BGP.
298
default-route imported
By default, BGP does not redistribute default routes.
Configuring BGP route summarization
About this task
Route summarization can reduce the number of redistributed routes and the routing table size. IPv4
BGP supports automatic route summarization and manual route summarization. Manual summarization takes precedence over automatic summarization. IPv6 BGP supports only manual route summarization.
Automatic route summarization enables BGP to summarize IGP subnet routes redistributed by the import-route command, so BGP advertises only natural network routes.
By configuring manual route summarization, you can do the following:
•
Summarize both redistributed routes and routes injected using the network command.
•
Determine the mask length for a summary route.
Restrictions and guidelines for configuring BGP route summarization
The output interface of a BGP summary route is Null 0 on the originating router. Therefore, a summary route must not be an optimal route on the originating router. Otherwise, BGP will fail to forward packets matching the route. If a summarized specific route has the same mask as the summary route, but has a lower priority, the summary route becomes the optimal route. To ensure correct packet forwarding, change the priority of the summary or specific route to make the specific route the optimal route.
Configuring automatic route summarization (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure automatic route summarization. summary automatic
By default, automatic route summarization is not configured.
Configuring manual route summarization (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
299
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Create a summary route in the BGP routing table. aggregate ipv4-address { mask-length | mask } [ as-set | attribute-policy route-policy-name | detail-suppressed | origin-policy route-policy-name | suppress-policy route-policy-name ]
*
By default, no summary routes are configured.
Configuring BGP manual route summarization (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Create a summary route in the IPv6 BGP routing table. aggregate ipv6-address prefix-length [ as-set | attribute-policy route-policy-name | detail-suppressed | origin-policy route-policy-name | suppress-policy route-policy-name ] *
By default, no summary routes are configured.
Advertising a default route to a peer or peer group
About this task
Perform this task to advertise a default BGP route with the next hop being the advertising router to a peer or peer group.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
300
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Advertise a default route to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } default-route-advertise [ route-policy route-policy-name ]
By default, no default route is advertised.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Advertise a default route to a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } default-route-advertise [ route-policy route-policy-name ]
By default, no default route is advertised.
Controlling BGP route advertisement
Advertising optimal routes in the IP routing table
About this task
By default, BGP advertises optimal routes in the BGP routing table, which may not be optimal in the
IP routing table. This task allows you to advertise BGP routes that are optimal in the IP routing table.
Procedure (IPv4 unicast)
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable BGP to advertise optimal routes in the IP routing table. advertise-rib-active
By default, BGP advertises optimal routes in the BGP routing table.
4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: address-family ipv4 [ unicast ]
301
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
5. Enable BGP to advertise optimal routes in the IP routing table of the address family in the VPN instance. advertise-rib-active
By default, the setting is the same as that in BGP instance view.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable BGP to advertise optimal routes in the IPv6 routing table. advertise-rib-active
By default, BGP advertises optimal routes in the BGP routing table.
4. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
5. Enable BGP to advertise optimal routes in the IPv6 routing table of the address family in the
VPN instance. advertise-rib-active
By default, the setting is the same as that in BGP instance view.
Enabling prioritized withdrawal of the default route
About this task
Typically a BGP router does not send withdrawal messages of the default route prior to other routes to its peers. If the peer relationship is down, the default route cannot be withdrawn first. Traffic interruption might occur. Perform this task to configure BGP to send the withdrawal messages of the default route prior to other routes. This can reduce the traffic interruption time when the peer relationship is down.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable BGP to send withdrawal messages of the default route prior to other routes. default-route update-first
By default, BGP does not send withdrawal messages of the default route prior to other routes.
302
Enabling prioritized withdrawal of specific routes
About this task
Perform this task to configure BGP to send the withdrawal messages of specific routes prior to other routes. This can achieve fast route switchover and reduce the traffic interruption time.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable BGP to send withdrawal messages of routes matching the specified routing policy prior to other routes. update-first route-policy route-policy-name
By default, BGP does not send withdrawal messages of specific routes prior to other routes.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable BGP to send withdrawal messages of routes matching the specified routing policy prior to other routes. update-first route-policy route-policy-name
By default, BGP does not send withdrawal messages of specific routes prior to other routes.
Configuring BGP route distribution filtering policies
About this task
To configure BGP route distribution filtering policies, use the following methods:
303
•
Use an ACL or prefix list to filter routing information advertised to all peers.
•
Use a routing policy, ACL, AS path list, or prefix list to filter routing information advertised to a peer or peer group.
2.
3.
4.
5.
If you configure multiple filtering policies, apply them in the following sequence:
1. filter-policy export peer filter-policy export peer as-path-acl export peer prefix-list export peer route-policy export
Only routes passing all the configured policies can be advertised.
Prerequisites
Before you configure BGP routing filtering policies, configure the following filters used for route filtering as needed:
•
ACL (see ACL and QoS Configuration Guide ).
•
Prefix list (see " Configuring routing policies ").
•
Routing policy (see " Configuring routing policies ").
•
AS path list (see " Configuring routing policies ").
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
address-family ipv4 [ unicast ]
3. Configure BGP route distribution filtering policies. Choose the options to configure as needed:
Reference an ACL or IP prefix list to filter advertised BGP routes. filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list ipv4-prefix-list-name } export [ direct | { isis | ospf | rip } process-id | static ]
Specify a routing policy as the existent policy to control route advertisement. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-policy advertise-policy-name exist-policy exist-policy-name
This command is available only in BGP IPv4 unicast address family view.
Specify a routing policy as the nonexistent policy to control route advertisement. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ]} advertise-policy advertise-policy-name non-exist-policy non-exist-policy-name
This command is available only in BGP IPv4 unicast address family view.
304
Reference a routing policy to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name export
Reference an ACL to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } filter-policy ipv4-acl-number export
Reference an AS path list to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } as-path-acl as-path-acl-number export
Reference an IPv4 prefix list to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } prefix-list ipv4-prefix-list-name export
By default, no BGP distribution filtering policy is configured.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure BGP route distribution filtering policies. Choose the options to configure as needed:
Reference an ACL or IPv6 prefix list to filter advertised BGP routes. filter-policy { ipv6-acl-number | name ipv6-acl-name | prefix-list ipv6-prefix-list-name } export [ direct | { isisv6 | ospfv3 | ripng } process-id | static ]
Specify a routing policy as the existent policy to control route advertisement. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-policy advertise-policy-name exist-policy exist-policy-name
This command is available only in BGP IPv6 unicast address family view.
Specify a routing policy as the nonexistent policy to control route advertisement. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-policy advertise-policy-name non-exist-policy non-exist-policy-name
This command is available only in BGP IPv6 unicast address family view.
Reference a routing policy to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name export
Reference an ACL to filter BGP routes advertised to a peer or peer group.
305
peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } filter-policy ipv6-acl-number export
Reference an AS path list to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } as-path-acl as-path-acl-number export
Reference an IPv6 prefix list to filter BGP routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } prefix-list ipv6-prefix-list-name export
By default, no BGP distribution filtering policy is configured.
Enabling first-AS-number check for EBGP routes before route advertisement
About this task
By default, BGP does not check the first AS number of a received EBGP route and directly advertises it to all peers except the source peer. The default setting for EBGP route advertisement brings about a large number of BGP routes and is not friendly to network maintenance.
To resolve this issue, perform this task. When the first AS number of an EBGP route to be advertised is the same as that of an EBGP peer, BGP does not advertise the route to that peer. This can reduce the number of routes received by EBGP peers.
Procedure (IPv4 unicast)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable BGP to perform first-AS-number check for EBGP routes before route advertisement. peer-as-check enable
By default, BGP does not check the first AS number of a received EBGP route and directly advertises it to all peers except the source peer.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
306
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable BGP to perform first-AS-number check for EBGP routes before route advertisement. peer-as-check enable
By default, BGP does not check the first AS number of a received EBGP route and directly advertises it to all peers except the source peer.
Setting the BGP route sending rate
About this task
If a device sends many new routes within a short time period, it might be unable to add the routes to the FIB before the peer device adds them. This might result in traffic forwarding failure. To avoid this problem, you can perform this task to set an appropriate route sending rate for the device.
Restrictions and guidelines
For a device with high performance, you can set a high BGP route sending rate as needed. For a device without high performance, set a relatively low BGP route sending rate as a best practice.
As a best practice to avoid route withdrawal failures, do not set the BGP route sending rate to 0 or a small value when network flapping occurs.
This task applies only to IPv4 unicast routes and IPv6 unicast routes.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Set the BGP route sending rate.
route-rate-limit rate
By default, the BGP route sending rate is not limited.
Configuring BGP route update delay
About this task
Perform this task to configure BGP to delay sending route updates on reboot to reduce traffic loss.
With this feature enabled, BGP redistributes all routes from other neighbors on reboot, selects the optimal route, and then advertises it.
You can specify a prefix list and enable BGP to immediately send route updates for routes that match the prefix list.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Configure BGP to delay sending route updates on reboot.
307
bgp update-delay on-startup seconds
By default, BGP immediately sends route updates on reboot.
4. (Optional.) Enable BGP to immediately send route updates for IPv4 routes that match a prefix list.
bgp update-delay on-startup prefix-list ipv4-prefix-list-name
By default, no prefix list is specified to filter IPv4 routes.
5. (Optional.) Enable BGP to immediately send route updates for IPv6 routes that match a prefix list.
bgp update-delay on-startup ipv6-prefix-list ipv6-prefix-list-name
By default, no prefix list is specified to filter IPv6 routes.
Configuring the interval for sending updates for the same route
About this task
A BGP router sends an UPDATE message to its peers when a route is changed. If the route changes frequently, the BGP router keeps sending updates for the same route, resulting route flapping. To prevent this situation, perform this task to configure the interval for sending updates for the same route to a peer or peer group.
This feature does not take effect on withdrawn routes. For withdrawn routes, BGP sends the withdrawal messages immediately.
Restrictions and guidelines
BGP compares the timer values specified for a BGP peer by using the route-update-delay command and the peer route-update-interval command. Only the larger timer value takes effect. If you did not execute the peer route-update-interval command, BGP compares the
BGP route advertisement delay timer with the default value of the peer route-update-interval command.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name
3. Configure the interval for sending updates for the same route to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } route-update-interval interval
By default, the interval is 15 seconds for an IBGP peer and 30 seconds for an EBGP peer.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
308
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name
3. Configure the interval for sending updates for the same route to a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } route-update-interval interval
By default, the interval is 15 seconds for an IBGP peer and 30 seconds for an EBGP peer.
Configuring BGP route advertisement delay
About this task
BGP sends update messages to peers when route changes occur. If a large number of routes need to be updated within a short time period, BGP might send update messages to peers before issuing the updated routes to the FIB. As a result, some packets might be discarded because BGP cannot find the forwarding path for the packets. To resolve this issue, perform this task to enable BGP route advertisement delay and set a delay timer.
Restrictions and guidelines
BGP compares the timer values specified for a BGP peer by using the route-update-delay command and the peer route-update-interval command. Only the larger timer value takes effect. If you did not execute the peer route-update-interval command, BGP compares the
BGP route advertisement delay timer with the default value of the peer route-update-interval command.
In the current software version, this feature applies to the following routes:
•
BGP IPv4 unicast routes.
•
BGP IPv6 unicast routes.
•
BGP VPNv4 routes.
•
BGP VPNv6 routes.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable BGP route advertisement delay and set a delay timer. route-update-delay delay-value
By default, BGP route advertisement delay is disabled.
Configuring a startup policy for BGP route updates
About this task
Perform this task to configure BGP to send route updates with the specified attributes within the specified period after reboot.
As shown in
Figure 74 , if Router B restarts and sends route updates before route convergence
completes, traffic sent from Router A through Router B might be lost. This feature enables Router B to send route updates with the specified attribute values within the specified period after reboot, so that Router A can forward traffic through Router C.
309
Figure 74 Network diagram
Router B
IP network
Router A
Router C
Procedure
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Specify the period after reboot within which the startup policy is effective.
bgp apply-policy on-startup duration seconds
By default, the startup policy does not take effect.
4. Specify a MED attribute value in the startup policy.
bgp policy on-startup med med-value
By default, the MED attribute value in the startup policy is 4294967295.
Setting the send buffer size for BGP sessions
About this task
A small send buffer size might cause a long convergence time when there are a large number of update messages to send. Perform this task to set an appropriate send buffer size to improve the convergence performance.
Restrictions and guidelines
This feature takes effect only on BGP sessions established or re-established after the feature is configured.
Procedure (global configuration)
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Set the send buffer size for BGP sessions.
send-buffer-size size
By default, the send buffer size is 32768 bytes.
Procedure (configuration for a peer or peer group)
1. Enter system view.
310
system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set the send buffer size for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } send-buffer-size size
By default, the send buffer size for a peer or peer group is not set. The send buffer size configured by the send-buffer-size command applies.
The configuration of this command takes precedence over that of the send-buffer-size command.
Configuring the BGP update message sending parameters
About this task
A BGP speaker uses update messages to advertise route updates to peers. Perform this task to prevent the device from sending a large number of update messages in a short time period, which saves system resources and improves the network convergence performance.
The BGP update message sending parameters are determined by the following configuration:
•
Update message sending interval and the maximum number of update messages can be sent each time.
•
Update message send queue parameters.
Restrictions and guidelines
This feature takes effect only on BGP sessions established or re-established after the feature is configured.
Setting the interval for sending update messages and the maximum number of update messages can be sent each time
Procedure (global configuration)
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Set the interval for sending update messages and the maximum number of update messages can be sent each time.
advertisement-interval interval count
311
By default, the interval for sending update messages and the maximum number of update messages can be sent each time are not set. When route update occurs, BGP sends update messages immediately, and the number of update messages can be sent each time is not limited.
Procedure (configuration for a peer or peer group)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set the interval for sending update messages and the maximum number of update messages can be sent each time to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertisement-interval interval count
By default, the interval for sending update messages and the maximum number of update messages can be sent each time to a peer or peer group are not set, and the configuration of the advertisement-interval command takes effect.
The configuration of this command takes precedence over that of the advertisement-interval command.
Setting the update message send queue parameters
About this task
BGP sessions take turns to send update messages. Before taking the turn, a BGP session queues up its update messages that need to be sent. If the number of messages in the send queue reaches the specified limit, the session stops generating update messages. The BGP session sends a specified quantity of update messages at the head of the send queue.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Set the update message send queue parameters. bgp queue-limit { packet packet-count | send send-count } *
By default, the maximum number of BGP update message in the send queue is 100 and the number of update messages sent each time is 5.
Controlling BGP route reception
Limiting routes received from a peer or peer group
About this task
This feature can prevent attacks that send a large number of BGP routes to the router.
312
If the number of routes received from a peer or peer group exceeds the upper limit, the router takes one of the following actions based on your configuration:
•
Tears down the BGP session to the peer or peer group and does not attempt to re-establish the session.
•
Continues to receive routes from the peer or peer group and generates a log message.
•
Retains the session to the peer or peer group, but it discards excess routes and generates a log message.
•
Tears down the BGP session to the peer or peer group and, after a specific period of time, re-establishes a BGP session to the peer or peer group.
You can specify a percentage threshold for the router to generate a log message. When the ratio of the number of received routes to the maximum number reaches the percentage value, the router generates a log message.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Specify the maximum number of routes that a router can receive from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ]} route-limit prefix-number [ { alert-only | discard | reconnect reconnect-time } | percentage-value ] *
By default, the number of routes that a router can receive from a peer or peer group is not limited.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Specify the maximum number of routes that a router can receive from a peer or peer group.
313
peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-limit prefix-number [ { alert-only | discard | reconnect reconnect-time } | percentage-value ] *
By default, the number of routes that a router can receive from a peer or peer group is not limited.
Configuring BGP route reception filtering policies
About this task
You can use the following methods to configure BGP route reception filtering policies:
•
Use an ACL or prefix list to filter routing information received from all peers.
•
Use a routing policy, ACL, AS path list, or prefix list to filter routing information received from a peer or peer group.
2.
3.
4.
5.
If you configure multiple filtering policies, apply them in the following sequence:
1. filter-policy import peer filter-policy import peer as-path-acl import peer prefix-list import peer route-policy import
Only routes passing all the configured policies can be received.
Prerequisites
Before you configure BGP route reception filtering policies, configure the following filters used for route filtering as needed:
•
ACL (see ACL and QoS Configuration Guide ).
•
Prefix list (see " Configuring routing policies ").
•
Routing policy (see " Configuring routing policies ").
•
AS path list (see " Configuring routing policies ").
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure BGP route reception filtering policies. Choose the options to configure as needed:
Reference an ACL or IP prefix list to filter BGP routes received from all peers. filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list ipv4-prefix-list-name } import
314
Reference a routing policy to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name import
Reference an ACL to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } filter-policy ipv4-acl-number import
Reference an AS path list to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } as-path-acl as-path-acl-number import
Reference an IPv4 prefix list to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } prefix-list ipv4-prefix-list-name import
By default, no route reception filtering is configured.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure BGP route reception filtering policies. Choose the options to configure as needed:
Reference ACL or IPv6 prefix list to filter BGP routes received from all peers. filter-policy { ipv6-acl-number | name ipv6-acl-name | prefix-list ipv6-prefix-list-name } import
Reference a routing policy to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name import
Reference an ACL to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } filter-policy ipv6-acl-number import
Reference an AS path list to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } as-path-acl as-path-acl-number import
Reference an IPv6 prefix list to filter BGP routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } prefix-list ipv6-prefix-list-name import
By default, no route reception filtering is configured.
315
Configuring the SoO attribute
About this task
After you configure the SoO attribute for a BGP peer or peer group, BGP adds the SoO attribute into the route updates received from the BGP peer or peer group. In addition, before advertising route updates to the peer or peer group, BGP checks the SoO attribute of the route update against the configured SoO attribute. If they are the same, BGP does not advertise the route updates to the BGP peer or peer group.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure the SoO attribute for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } soo site-of-origin
By default, no SoO attribute is configured for a peer or peer group.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure the SoO attribute for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } soo site-of-origin
By default, no SoO attribute is configured for a peer or peer group.
316
Configuring the link bandwidth attribute
About this task
Perform this task to add the link bandwidth attribute to routes received from a directly connected
EBGP peer or peer group. The link bandwidth is the bandwidth of the interface directly connected to the EBGP peer or peer group. After BGP advertises the routes received from the EBGP peer or peer group to other IBGP peers, the IBGP peers can filter routes based on the link bandwidth attribute.
Restrictions and guidelines
This feature is applicable only to directly connected EBGP peers and peer groups.
If a directly connected EBGP peer or peer group changes to an indirectly connected one, BGP stops adding the link bandwidth attribute to routes received from the EBGP peer or peer group.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable BGP to add the link bandwidth attribute to routes received from an EBGP peer or peer group. peer { group-name | ipv4-address [ mask-length ] } bandwidth
By default, BGP does not add the link bandwidth attribute to routes received from an EBGP peer or peer group.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable BGP to add the link bandwidth attribute to routes received from an EBGP peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } bandwidth
317
By default, BGP does not add the link bandwidth attribute to routes received from an EBGP peer or peer group.
Configuring BGP timers
Configuring the keepalive interval and hold time
About this task
BGP sends KEEPALIVE messages regularly to keep the BGP session between two routers.
If a router receives no KEEPALIVE or UPDATE message from a peer within the hold time, it tears down the session.
You can configure the keepalive interval and hold time globally or for a peer or peer group. The individual settings take precedence over the global settings.
The actual keepalive interval and hold time are determined as follows:
•
If the hold time settings on the local and peer routers are different, the smaller setting is used. If the hold time is 0, BGP does not send KEEPALIVE messages to its peers and never tears down the session.
•
If the keepalive interval is not 0, the actual keepalive interval is the smaller one between 1/3 of the hold time and the keepalive interval.
Restrictions and guidelines
The hold time must be a minimum of three times the keepalive interval.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name
3. Configure the keepalive interval and hold time.
Configure the global keepalive interval and hold time.
timer keepalive keepalive hold holdtime
This command takes effect for new BGP sessions and does not affect existing sessions.
Configure the keepalive interval and hold time for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } timer keepalive keepalive hold holdtime
By default, the keepalive interval is 60 seconds, and hold time is 180 seconds.
The timers configured with the timer and peer timer commands do not take effect until a session is re-established (for example, a session is reset).
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
318
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ] ip vpn-instance vpn-instance-name
3. Configure the keepalive interval and hold time.
Configure the global keepalive interval and hold time.
timer keepalive keepalive hold holdtime
This command takes effect for new BGP sessions and does not affect existing sessions.
Configure the keepalive interval and hold time for a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } timer keepalive keepalive hold holdtime
By default, the keepalive interval is 60 seconds, and hold time is 180 seconds.
The timers configured with the timer and peer timer commands do not take effect until a session is re-established (for example, a session is reset).
Setting the session retry timer
About this task
To speed up session establishment to a peer or peer group and route convergence, set a small session retry timer. If the BGP session flaps, you can set a large session retry timer to reduce the impact.
Restrictions and guidelines
The timer set by the peer timer connect-retry command takes precedence over the timer set by the timer connect-retry command.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set the session retry timer.
Set the session retry timer for all peers or peer groups.
timer connect-retry retry-time
Set the session retry timer for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } timer
connect-retry retry-time
By default, the session retry timer is 32 seconds for a peer or peer group.
Procedure (IPv6 peers)
1. Enter system view. system-view
319
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set the session retry timer.
Set the session retry timer for all peers or peer groups.
timer connect-retry retry-time
Set the session retry timer for a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] | link-local-address interface interface-type interface-number } timer connect-retry retry-time
By default, the session retry timer is 32 seconds for a peer or peer group.
Setting an update delay for local MPLS labels
About this task
BGP includes local MPLS labels in advertised VPNv4 routes, VPNv6 routes, labeled IPv6 unicast routes, and labeled IPv4 unicast routes.
When a local label is changed, BGP removes the old label and advertises the new label. Traffic interruption occurs if BGP peers use the old label to forward packets before they learn the new label.
To resolve this issue, set an update delay for local MPLS labels. BGP does not remove the old label before the update delay timer expires.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Set an update delay for local MPLS labels. retain local-label retain-time
By default, the update delay is 60 seconds.
Configuring BGP logging and notifications
Enabling logging for session state changes
About this task
Perform this task to enable BGP to log BGP session establishment and disconnection events. To display the log information, use the display bgp peer ipv4 unicast log-info command or the display bgp peer ipv6 unicast log-info command. The logs are sent to the information center. The output rules of the logs (whether to output the logs and where to output) are determined by the information center configuration.
For more information about information center configuration, see Network Management and
Monitoring Configuration Guide .
320
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable logging for session state changes globally. log-peer-change
By default, logging for session state changes is enabled globally.
4. (Optional.) Enter BGP-VPN instance view. ip vpn-instance vpn-instance-name
5. Enable logging for session state changes for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } log-change
By default, logging for session state changes is enabled for all peers and peer groups.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable logging for session state changes globally. log-peer-change
By default, logging for session state changes is enabled globally.
4. (Optional.) Enter BGP-VPN instance view. ip vpn-instance vpn-instance-name
5. Enable logging for session state changes for a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } log-change
By default, logging for session state changes is enabled for all peers and peer groups.
Enabling logging for BGP route flapping
About this task
This feature enables BGP to generate logs for BGP route flapping events that trigger log generation.
The generated logs are sent to the information center. For the logs to be output correctly, you must also configure information center on the device. For more information about the information center, see Network Management and Monitoring Configuration Guide .
Procedure (IPv4 unicast)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
321
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable logging for BGP route flapping. log-route-flap monitor-time monitor-count [ log-count-limit | route-policy route-policy-name ] *
By default, logging for BGP route flapping is disabled.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable logging for BGP route flapping. log-route-flap monitor-time monitor-count [ log-count-limit | route-policy route-policy-name ] *
By default, logging for BGP route flapping is disabled.
Configuring BGP network management
About this task
After you enable SNMP notifications for BGP, the device generates a notification when a BGP neighbor state change occurs. The notification includes the neighbor address, the error code and subcode of the most recent error, and the current neighbor state. For BGP notifications to be sent correctly, you must also configure SNMP on the device.
BGP does not know the BGP instance to which a managed MIB node belongs. To resolve this issue, configure different SNMP contexts for different BGP instances.
The device selects a MIB for an SNMP packet according to the context (for SNMPv3) or community name (for SNMPv1/v2c) in the following ways:
•
For an SNMPv3 packet:
The device selects the MIB of the default BGP instance if the packet does not carry a context and no SNMP context is configured for the default BGP instance.
The device selects the MIB of a BGP instance if the packet meets the following conditions:
−
Carries a context that is configured with the snmp-agent context command in system view.
−
Matches the context of the BGP instance.
The device does not process any MIBs in other situations.
•
For an SNMPv1/v2c packet:
The device selects the MIB of the default BGP instance if the following conditions are met:
322
−
No community name-to-SNMP context mapping is configured with the snmp-agent community-map command in system view.
−
No SNMP context is configured for the default BGP instance.
The device selects the MIB of a BGP instance if the community name is mapped to an
SNMP context and the context matches the context of the BGP instance.
The device does not process any MIBs in other situations.
For more information about SNMP contexts and community names, see SNMP configuration in
Network Management and Monitoring Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enable SNMP notifications for BGP. snmp-agent trap enable bgp [ instance instance-name ]
By default, SNMP notifications for BGP are enabled.
3. Enter BGP instance view.
bgp as-number [ instance instance-name ]
4. Configure an SNMP context for the BGP instance.
snmp context-name context-name
By default, no SNMP context is configured for the BGP instance.
Verifying and maintaining basic BGP network configuration
Verifying BGP configuration and running status (IPv4 unicast address family)
Perform display tasks in any view.
•
Display BGP IPv4 unicast peer group information.
display bgp [ instance instance-name ] group ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ group-name group-name ]
•
Display information about a peer or peer group in BGP IPv4 unicast address family.
display bgp [ instance instance-name ] peer ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address mask-length |
{ ipv4-address | group-name group-name } log-info | [ ipv4-address ] verbose ] display bgp [ instance instance-name ] peer ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length |
ipv6-address log-info | [ ipv6-address ] verbose ] display bgp [ instance instance-name ] peer ipv4 [ unicast ] vpn-instance-all [ verbose ]
•
Display information about routes advertised by the network command and shortcut routes configured by the network short-cut command.
display bgp [ instance instance-name ] network ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ]
•
Display BGP IPv4 unicast route information.
323
display bgp [ instance instance-name ] routing-table ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address [ { mask-length | mask } [ longest-match ] ] | ipv4-address [ mask-length | mask ] advertise-info | as-path-acl { as-path-acl-number | as-path-acl-name }
| community-list { { basic-community-list-number | comm-list-name }
[ whole-match ] | adv-community-list-number } | peer { ipv4-address | ipv6-address } { advertised-routes | received-routes } [ ipv4-address
[ mask-length | mask ] | statistics ] | statistics ]
•
Display information about BGP peer relationship down events. display bgp [ instance instance-name ] troubleshooting [ event-count ]
[ reverse ]
•
Display BGP IPv4 unicast address family update group information.
display bgp [ instance instance-name ] update-group ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address | ipv6-address ]
•
Display summary information about BGP peers and routes. display bgp [ instance instance-name ] ipv4 vpn-instance vpn-instance-name summary
•
Display information about all BGP instances. display bgp instance-info
Verifying BGP configuration and running status (IPv6 unicast address family)
Perform display tasks in any view.
•
Display BGP IPv6 unicast peer group information.
display bgp [ instance instance-name ] group ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ group-name group-name ]
•
Display information about a peer or peer group in BGP IPv6 unicast address family.
display bgp [ instance instance-name ] peer ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length |
{ ipv6-address | group-name group-name } log-info | [ ipv6-address ] verbose ]
display bgp [ instance instance-name ] peer ipv6 [ unicast ]
[ ipv4-address mask-length | ipv4-address log-info | [ ipv4-address ] verbose ] display bgp [ instance instance-name ] peer ipv6 [ unicast ] vpn-instance-all [ verbose ]
•
Display information about routes advertised by the network command and shortcut routes configured by the network short-cut command.
display bgp [ instance instance-name ] network ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ]
display bgp [ instance instance-name ] peer ipv6 [ unicast ]
[ ipv4-address mask-length | ipv4-address log-info | [ ipv4-address ] verbose ] display bgp [ instance instance-name ] peer ipv6 [ unicast ] vpn-instance-all [ verbose ]
•
Display BGP IPv6 unicast route information.
324
display bgp [ instance instance-name ] routing-table ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length
[ advertise-info ] | as-path-acl { as-path-acl-number | as-path-acl-name } | community-list { { basic-community-list-number
| comm-list-name } [ whole-match ] | adv-community-list-number } | peer ipv6-address { advertised-routes | received-routes } [ ipv6-address prefix-length | statistics ] | statistics ]
display bgp [ instance instance-name ] routing-table ipv6 [ unicast ]
peer ipv4-address { advertised-routes | received-routes }
[ ipv6-address prefix-length | statistics ]
•
Display information about BGP peer relationship down events. display bgp [ instance instance-name ] troubleshooting [ event-count ]
[ reverse ]
•
Display BGP IPv6 unicast address family update group information.
display bgp [ instance instance-name ] update-group ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address | ipv6-address ]
•
Display summary information about BGP peers and routes. display bgp [ instance instance-name ] ipv6 vpn-instance vpn-instance-name summary
•
Display information about all BGP instances. display bgp instance-info
Resetting BGP sessions
About this task
A reset operation enables the router to apply a new route selection policy by re-establishing BGP sessions. This operation breaks down BGP sessions for a short period of time.
Restrictions and guidelines
A reset operation tears down BGP sessions for a short period of time.
Procedure
Perform reset tasks in user view.
•
Reset BGP sessions for IPv4 unicast address family. reset bgp [ instance instance-name ] { as-number | ipv4-address
[ mask-length ] | all | external | group group-name | internal } ipv4
[ unicast ] [ vpn-instance vpn-instance-name ] reset bgp ipv6-address [ mask-length ] ipv4 [ unicast ]
•
Reset BGP sessions for IPv6 unicast address family. reset bgp [ instance instance-name ] { as-number | ipv6-address
[ prefix-length ] | all | external | group group-name | internal } ipv6
[ unicast ] [ vpn-instance vpn-instance-name ] reset bgp ipv4-address [ mask-length ] ipv6 [ unicast ]
•
Reset all BGP sessions. reset bgp [ instance instance-name ] all
325
Displaying and clearing BGP route flapping statistics
Displaying BGP route flapping statistics
Perform display tasks in any view.
•
Display BGP IPv4 unicast route flapping statistics.
display bgp [ instance instance-name ] routing-table flap-info ipv4
[ unicast ] [ vpn-instance vpn-instance-name ] [ ipv4-address
[ { mask-length | mask } [ longest-match ] ] | as-path-acl
{ as-path-acl-number | as-path-acl-name } ]
•
Display BGP IPv6 unicast route flapping statistics.
display bgp [ instance instance-name ] routing-table flap-info ipv6
[ unicast ] [ vpn-instance vpn-instance-name ] [ ipv6-address
prefix-length | as-path-acl { as-path-acl-number | as-path-acl-name } ]
Clearing BGP route flapping statistics
Perform clear tasks in user view.
•
Clear BGP IPv4 unicast route flapping statistics. reset bgp [ instance instance-name ] flap-info ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ][ ipv4-address [ mask-length | mask ]
| as-path-acl { as-path-acl-number | as-path-acl-name } | peer ipv4-address [ mask-length ] ]
•
Clear BGP IPv6 unicast route flapping statistics. reset bgp [ instance instance-name ] flap-info ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length | as-path-acl { as-path-acl-number | as-path-acl-name } | peer ipv6-address [ prefix-length ] ]
Basic IPv4 BGP network configuration examples
Example: Configuring basic BGP
Network configuration
As shown in Figure 75 , all devices run BGP. Run EBGP between Device A and Device B, and run
IBGP between Device B and Device C to allow Device C to access network 8.1.1.0/24 connected to
Device A.
Figure 75 Network diagram
HGE1/0/1
8.1.1.1/24
Loop0
1.1.1.1/32
AS 65008
EBGP
AS 65009
Loop0
2.2.2.2/32
HGE1/0/2
Device A
3.1.1.2/24
IBGP
Loop0
3.3.3.3/32
HGE1/0/1
3.1.1.1/24
HGE1/0/2
Device B
9.1.1.1/24
HGE1/0/1
9.1.1.2/24
Device C
326
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IBGP:
To prevent route flapping caused by port state changes, this example uses loopback interfaces to establish IBGP connections.
Because loopback interfaces are virtual interfaces, you need to use the peer connect-interface command to specify the loopback interface as the source interface for establishing BGP connections.
Enable OSPF in AS 65009 to ensure that Device B can communicate with Device C through loopback interfaces.
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 65009
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 3.3.3.3 as-number 65009
[DeviceB-bgp-default] peer 3.3.3.3 connect-interface loopback 0
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 3.3.3.3 enable
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
[DeviceB] ospf 1
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[DeviceB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 65009
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 2.2.2.2 as-number 65009
[DeviceC-bgp-default] peer 2.2.2.2 connect-interface loopback 0
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 2.2.2.2 enable
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
[DeviceC] ospf 1
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 3.3.3.3 0.0.0.0
[DeviceC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
[DeviceC] display bgp peer ipv4
327
BGP local router ID : 3.3.3.3
Local AS number : 65009
Total number of peers : 1 Peers in established state : 1
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
2.2.2.2 65009 7 10 0 0 00:06:09 Established
The output shows that Device C has established an IBGP peer relationship with Device B.
3. Configure EBGP:
The EBGP peers, Device A and Device B (usually in different ISPs), are located in different
ASs. Typically, their loopback interfaces are not reachable to each other, so directly connected interfaces are used for establishing EBGP sessions.
To enable Device C to access the network 8.1.1.0/24 connected directly to Device A, inject network 8.1.1.0/24 to the BGP routing table of Device A.
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 65008
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 3.1.1.1 as-number 65009
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 3.1.1.1 enable
[DeviceA-bgp-default-ipv4] network 8.1.1.0 24
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
[DeviceB] bgp 65009
[DeviceB-bgp-default] peer 3.1.1.2 as-number 65008
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 3.1.1.2 enable
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Display BGP peer information on Device B.
[DeviceB] display bgp peer ipv4
BGP local router ID : 2.2.2.2
Local AS number : 65009
Total number of peers : 2 Peers in established state : 2
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
3.3.3.3 65009 12 10 0 3 00:09:16 Established
3.1.1.2 65008 3 3 0 1 00:00:08 Established
The output shows that Device B has established an IBGP peer relationship with Device C and an EBGP peer relationship with Device A.
# Display the BGP routing table on Device A.
328
[ DeviceA ] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* > 8.1.1.0/24 8.1.1.1 0 32768 i
# Display the BGP routing table on Device B.
[ DeviceB ] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 8.1.1.0/24 3.1.1.2 0 0 65008i
# Display the BGP routing table on Device C.
[ DeviceC ] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
i 8.1.1.0/24 3.1.1.2 0 100 0 65008i
The outputs show that Device A has no route to AS 65009, and Device C has learned network
8.1.1.0, but the next hop 3.1.1.2 is unreachable. As a result, the route is invalid.
4. Redistribute direct routes:
Configure BGP to redistribute direct routes on Device B, so Device A can obtain the route to
9.1.1.0/24, and Device C can obtain the route to 3.1.1.0/24.
# Configure Device B.
[DeviceB] bgp 65009
329
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] import-route direct
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Display the BGP routing table on Device A.
[ DeviceA ] display bgp routing-table ipv4
Total number of routes: 4
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 2.2.2.2/32 3.1.1.1 0 0 65009?
* >e 3.1.1.0/24 3.1.1.1 0 0 65009?
* > 8.1.1.0/24 8.1.1.1 0 32768 i
* >e 9.1.1.0/24 3.1.1.1 0 0 65009?
Two routes 2.2.2.2/32 and 9.1.1.0/24 have been added in Device A's routing table.
# Display the BGP routing table on Device C.
[ DeviceC ] display bgp routing-table ipv4
Total number of routes: 4
BGP local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 2.2.2.2/32 2.2.2.2 0 100 0 ?
* >i 3.1.1.0/24 2.2.2.2 0 100 0 ?
* >i 8.1.1.0/24 3.1.1.2 0 100 0 65008i
* >i 9.1.1.0/24 2.2.2.2 0 100 0 ?
The output shows that the route 8.1.1.0 has become valid and the next hop is Device A.
Verifying the configuration
# Verify that Device C can ping 8.1.1.1.
[DeviceC] ping 8.1.1.1
Ping 8.1.1.1 (8.1.1.1): 56 data bytes, press CTRL_C to break
56 bytes from 8.1.1.1: icmp_seq=0 ttl=255 time=2.000 ms
56 bytes from 8.1.1.1: icmp_seq=1 ttl=255 time=0.000 ms
56 bytes from 8.1.1.1: icmp_seq=2 ttl=255 time=0.000 ms
330
56 bytes from 8.1.1.1: icmp_seq=3 ttl=255 time=0.000 ms
56 bytes from 8.1.1.1: icmp_seq=4 ttl=255 time=1.000 ms
--- Ping statistics for 8.1.1.1 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 0.000/0.600/2.000/0.800 ms
Example: Configuring BGP and IGP route redistribution
Network configuration
As shown in Figure 76 , all devices of company A belong to AS 65008 and all devices of company B
belong to AS 65009.
Configure BGP and IGP route redistribution to allow Device A to access network 9.1.2.0/24 in AS
65009, and Device C to access network 8.1.1.0/24 in AS 65008.
Figure 76 Network diagram
HGE1/0/1
8.1.1.1/24
Loop0
1.1.1.1/32
AS 65008
EBGP
AS 65009
Loop0
2.2.2.2/32
Device A
HGE1/0/2
3.1.1.2/24
HGE1/0/1
3.1.1.1/24
Device B
HGE1/0/2
9.1.1.1/24
OSPF
HGE1/0/1
9.1.1.2/24
Loop0
3.3.3.3/32
Device C
HGE1/0/2
9.1.2.1/24
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF:
Enable OSPF in AS 65009, so Device B can obtain the route to 9.1.2.0/24.
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf 1
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[DeviceB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf 1
[DeviceC-ospf-1] import-route direct
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
331
[DeviceC-ospf-1] quit
3. Configure the EBGP connection:
Configure the EBGP connection and inject network 8.1.1.0/24 to the BGP routing table of
Device A, so Device B can obtain the route to 8.1.1.0/24.
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 65008
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 3.1.1.1 as-number 65009
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 3.1.1.1 enable
[DeviceA-bgp-default-ipv4] network 8.1.1.0 24
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
[DeviceB] bgp 65009
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 3.1.1.2 as-number 65008
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 3.1.1.2 enable
4. Configure BGP and IGP route redistribution:
Configure BGP to redistribute routes from OSPF on Device B, so Device A can obtain the route to 9.1.2.0/24.
Configure OSPF to redistribute routes from BGP on Device B, so that Device C can obtain the route to 8.1.1.0/24.
# Configure route redistribution between BGP and OSPF on Device B.
[DeviceB-bgp-default-ipv4] import-route ospf 1
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
[DeviceB] ospf 1
[DeviceB-ospf-1] import-route bgp
[DeviceB-ospf-1] quit
# Display the BGP routing table on Device A.
[ DeviceA ] display bgp routing-table ipv4
Total number of routes: 3
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 3.3.3.3/32 3.1.1.1 1 0 65009?
* > 8.1.1.0/24 8.1.1.1 0 32768 i
* >e 9.1.2.0/24 3.1.1.1 1 0 65009?
332
# Display the OSPF routing table on Device C.
[DeviceC] display ospf routing
OSPF Process 1 with Router ID 3.3.3.3
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
9.1.1.0/24 1 Transit 9.1.1.2 3.3.3.3 0.0.0.0
2.2.2.2/32 1 Stub 9.1.1.1 2.2.2.2 0.0.0.0
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
8.1.1.0/24 1 Type2 1 9.1.1.1 2.2.2.2
Total Nets: 3
Intra Area: 2 Inter Area: 0 ASE: 1 NSSA: 0
Verifying the configuration
# Use ping to test connectivity.
[DeviceA] ping -a 8.1.1.1 9.1.2.1
Ping 9.1.2.1 (9.1.2.1) from 8.1.1.1: 56 data bytes, press CTRL_C to break
56 bytes from 9.1.2.1: icmp_seq=0 ttl=254 time=10.000 ms
56 bytes from 9.1.2.1: icmp_seq=1 ttl=254 time=12.000 ms
56 bytes from 9.1.2.1: icmp_seq=2 ttl=254 time=2.000 ms
56 bytes from 9.1.2.1: icmp_seq=3 ttl=254 time=7.000 ms
56 bytes from 9.1.2.1: icmp_seq=4 ttl=254 time=9.000 ms
--- Ping statistics for 9.1.2.1 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 2.000/8.000/12.000/3.406 ms
[DeviceC] ping -a 9.1.2.1 8.1.1.1
Ping 8.1.1.1 (8.1.1.1) from 9.1.2.1: 56 data bytes, press CTRL_C to break
56 bytes from 8.1.1.1: icmp_seq=0 ttl=254 time=9.000 ms
56 bytes from 8.1.1.1: icmp_seq=1 ttl=254 time=4.000 ms
56 bytes from 8.1.1.1: icmp_seq=2 ttl=254 time=3.000 ms
56 bytes from 8.1.1.1: icmp_seq=3 ttl=254 time=3.000 ms
56 bytes from 8.1.1.1: icmp_seq=4 ttl=254 time=3.000 ms
--- Ping statistics for 8.1.1.1 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 3.000/4.400/9.000/2.332 ms
Example: Configuring dynamic BGP peers
Network configuration
As shown in Figure 77 , Device A needs to establish IBGP peer relationships with Device B, Device C,
and Device D in network 10.1.0.0/16. Configure dynamic BGP peers to simplify the configuration.
333
Configure Device A as the route reflector, and configure Device B, Device C, and Device D as its clients.
Figure 77 Network diagram
AS 200
HGE1/0/1
10.1.1.2/24
Device B
Device A
HGE1/0/1
10.1.1.1/24
HGE1/0/3
10.1.3.1/24
HGE1/0/2
10.1.2.1/24
HGE1/0/1
10.1.2.2/24
Device C
HGE1/0/2
9.1.1.1
HGE1/0/1
10.1.3.2/24
Device D
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IBGP peer relationships:
# Configure Device A to establish dynamic BGP peer relationships with devices in network
10.1.0.0/16.
<DeviceA> system-view
[DeviceA] bgp 200
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 10.1.0.0 16 as-number 200
[DeviceA-bgp-default] address-family ipv4
[DeviceA-bgp-default-ipv4] peer 10.1.0.0 16 enable
# Configure Device B to establish an IBGP peer relationship with Device A.
<DeviceB> system-view
[DeviceB] bgp 200
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 10.1.1.1 as-number 200
[DeviceB-bgp-default] address-family ipv4
[DeviceB-bgp-default-ipv4] peer 10.1.1.1 enable
# Configure Device C to establish an IBGP peer relationship with Device A.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC-bgp-default] router-id 3.3.3.3
334
[DeviceC-bgp-default] peer 10.1.2.1 as-number 200
[DeviceC-bgp-default] address-family ipv4
[DeviceC-bgp-default-ipv4] peer 10.1.2.1 enable
# Configure Device D to establish an IBGP peer relationship with Device A.
<DeviceD> system-view
[DeviceD] bgp 200
[DeviceD-bgp-default] router-id 4.4.4.4
[DeviceD-bgp-default] peer 10.1.3.1 as-number 200
[DeviceD-bgp-default] address-family ipv4
[DeviceD-bgp-default-ipv4] peer 10.1.3.1 enable
# Display BGP peer information on Device A. The output shows that Device A has established
IBGP peer relationships with Device B, Device C, and Device D.
[DeviceA] display bgp peer ipv4
BGP local router ID : 1.1.1.1
Local AS number : 200
Total number of peers : 3 Peers in established state : 3
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
*10.1.1.2 200 7 10 0 0 00:06:09 Established
*10.1.2.2 200 7 10 0 0 00:06:09 Established
*10.1.3.2 200 7 10 0 0 00:06:09 Established
3. Configure Device A as the route reflector, and configure peers in network 10.1.0.0/16 as its clients.
[DeviceA-bgp-default-ipv4] peer 10.1.0.0 16 reflect-client
4. Configure Device C to advertise network 9.1.1.0/24.
[DeviceC-bgp-default-ipv4] network 9.1.1.0 24
Verifying the configuration
# Verify that route 9.1.1.0/24 exists in the BGP routing table on Device A, Device B, Device D. This example uses Device A.
[ DeviceA-bgp-default ] display bgp routing-table ipv4
Total Number of Routes: 1
BGP Local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* i 9.1.1.0/24 10.1.2.2 0 100 0 ?
335
Example: Configuring BGP route summarization
Network configuration
As shown in Figure 78 , run EBGP between Device C and Device D, so the internal network and
external network can communicate with each other.
•
In AS 65106, perform the following configurations so the devices in the internal network can communicate:
Configure static routing between Device A and Device B.
Configure OSPF between Device B and Device C.
Configure OSPF to redistribute static routes.
•
Configure route summarization on Device C so BGP advertises a summary route instead of advertising routes to the 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 networks to
Device D.
Figure 78 Network diagram
Internal network
AS 65106
Device B
Core layer device
Device A
Distribution layer device
HGE1/0/1
192.168.212.1/24
Loop0
1.1.1.1/32
Loop0
2.2.2.2/32
HGE1/0/2
172.17.100.1/24 External network
AS 64631
Loop0
3.3.3.3/32
Loop0
4.4.4.4/32
HGE1/0/1
192.168.212.161/24
HGE1/0/1
172.17.100.2/24
Device C
HGE1/0/2
10.220.2.16/24
Boundary device
HGE1/0/1
10.220.2.217/24
Device D
External network device
192.168.64.0/24 192.168.74.0/24 192.168.99.0/24
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routing between Device A and Device B:
# Configure a default route with the next hop 192.168.212.1 on Device A.
<DeviceA> system-view
[DeviceA] ip route-static 0.0.0.0 0 192.168.212.1
# Configure static routes to 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 with the same next hop 192.168.212.161 on Device B.
<DeviceB> system-view
[DeviceB] ip route-static 192.168.64.0 24 192.168.212.161
[DeviceB] ip route-static 192.168.74.0 24 192.168.212.161
[DeviceB] ip route-static 192.168.99.0 24 192.168.212.161
3. Configure OSPF between Device B and Device C and configure OSPF on Device B to redistribute static routes:
336
# Configure OSPF to advertise the local network and enable OSPF to redistribute static routes on Device B.
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] import-route static
[DeviceB-ospf-1] quit
# Configure OSPF to advertise local networks on Device C.
[DeviceC] ospf
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] network 10.220.2.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
# Display the IP routing table on Device C.
[DeviceC] display ip routing-table protocol ospf
Summary count : 5
OSPF Routing table Status : <Active>
Summary count : 3
Destination/Mask Proto Pre Cost NextHop Interface
192.168.64.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
192.168.74.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
192.168.99.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
OSPF Routing table Status : <Inactive>
Summary count : 2
Destination/Mask Proto Pre Cost NextHop Interface
10.220.2.0/24 O_INTRA 10 1 10.220.2.16 HGE1/0/2
172.17.100.0/24 O_INTRA 10 1 172.17.100.2 HGE1/0/1
The output shows that Device C has learned routes to 192.168.64.0/24, 192.168.74.0/24, and
192.168.99.0/24 through OSPF.
4. Configure BGP between Device C and Device D and configure BGP on Device C to redistribute
OSPF routes:
# On Device C, enable BGP, specify Device D as an EBGP peer, and configure BGP to redistribute OSPF routes.
[DeviceC] bgp 65106
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 10.220.2.217 as-number 64631
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 10.220.2.217 enable
[DeviceC-bgp-default-ipv4] import-route ospf
# Enable BGP, and configure Device C as an EBGP peer on Device D.
[DeviceD] bgp 64631
[DeviceD-bgp-default] router-id 4.4.4.4
337
[DeviceD-bgp-default] peer 10.220.2.16 as-number 65106
[DeviceD-bgp-default] address-family ipv4 unicast
[DeviceD-bgp-default-ipv4] peer 10.220.2.16 enable
[DeviceD-bgp-default-ipv4] quit
[DeviceD-bgp-default] quit
# Display routing table information on Device D.
[DeviceD] display ip routing-table protocol bgp
Summary count : 3
BGP Routing table Status : <Active>
Summary count : 3
Destination/Mask Proto Pre Cost NextHop Interface
192.168.64.0/24 BGP 255 1 10.220.2.16 HGE1/0/1
192.168.74.0/24 BGP 255 1 10.220.2.16 HGE1/0/1
192.168.99.0/24 BGP 255 1 10.220.2.16 HGE1/0/1
BGP Routing table Status : <Inactive>
Summary count : 0
The output shows that Device D has learned routes to 192.168.64.0/24, 192.168.74.0/24, and
192.168.99.0/24 through BGP.
# Ping the hosts on networks 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 from
Device D. The ping operations succeed.
5. Configure route summarization on Device C to summarize 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 into a single route 192.168.64.0/18, and disable advertisement of specific routes.
[DeviceC-bgp-default-ipv4] aggregate 192.168.64.0 18 detail-suppressed
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
Verifying the configuration
# Display IP routing table information on Device C.
[ DeviceC ] display ip routing-table | include 192.168
192.168.64.0/18 BGP 130 0 127.0.0.1 NULL0
192.168.64.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
192.168.74.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
192.168.99.0/24 O_ASE2 150 1 172.17.100.1 HGE1/0/1
The output shows that Device C has a summary route 192.168.64.0/18 with the output interface Null
0.
# Display the IP routing table information on Device D.
[DeviceD] display ip routing-table protocol bgp
Summary count : 1
BGP Routing table Status : <Active>
Summary count : 1
Destination/Mask Proto Pre Cost NextHop Interface
338
192.168.64.0/18 BGP 255 0 10.220.2.16 HGE1/0/1
BGP Routing table Status : <Inactive>
Summary count : 0
The output shows that Device D has only one route 192.168.64.0/18 to AS 65106.
# Verify that Device D can ping the hosts on subnets 192.168.64.0/24, 192.168.74.0/24, and
192.168.99.0/24. (Details not shown.)
Basic IPv6 BGP network configuration examples
Example: Configuring IPv6 BGP basics
Network configuration
As shown in Figure 79 , all devices run BGP. Run EBGP between Device A and Device B, and run
IBGP between Device B and Device C to allow Device C to access network 50::/64 connected to
Device A.
Figure 79 Network diagram
Loop0
1.1.1.1/32
AS 65008 AS 65009
Loop0
2.2.2.2/32
Loop0
3.3.3.3/32
HGE1/0/1
50::1/64
Device A
HGE1/0/2
10::2/64
EBGP IBGP
HGE1/0/1
10::1/64
HGE1/0/2
Device B
9::1/64
HGE1/0/1
9::2/64
Device C
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IBGP:
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 65009
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 9::2 as-number 65009
[DeviceB-bgp-default] address-family ipv6
[DeviceB-bgp-default-ipv6] peer 9::2 enable
[DeviceB-bgp-default-ipv6] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 65009
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 9::1 as-number 65009
339
[DeviceC-bgp-default] address-family ipv6
[DeviceC-bgp-default-ipv6] peer 9::1 enable
3. Configure EBGP:
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 65008
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 10::1 as-number 65009
[DeviceA-bgp-default] address-family ipv6
[DeviceA-bgp-default-ipv6] peer 10::1 enable
# Configure Device B.
[DeviceB-bgp-default] peer 10::2 as-number 65008
[DeviceB-bgp-default] address-family ipv6
[DeviceB-bgp-default-ipv6] peer 10::2 enable
4. Inject network routes to the BGP routing table:
# Configure Device A.
[DeviceA-bgp-default-ipv6] network 10:: 64
[DeviceA-bgp-default-ipv6] network 50:: 64
[DeviceA-bgp-default-ipv6] quit
[DeviceA-bgp-default] quit
# Configure Device B.
[DeviceB-bgp-default-ipv6] network 10:: 64
[DeviceB-bgp-default-ipv6] network 9:: 64
[DeviceB-bgp-default-ipv6] quit
[DeviceB-bgp-default] quit
# Configure Device C.
[DeviceC-bgp-default-ipv6] network 9:: 64
[DeviceC-bgp-default-ipv6] quit
[DeviceC-bgp-default] quit
Verifying the configuration
# Display IPv6 BGP peer information on Device B.
[DeviceB] display bgp peer ipv6
BGP local router ID: 2.2.2.2
Local AS number: 65009
Total number of peers: 2 Peers in established state: 2
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
9::2 65009 41 43 0 1 00:29:00 Established
10::2 65008 38 38 0 2 00:27:20 Established
The output shows that Device A and Device B have established an EBGP connection, and Device B and Device C have established an IBGP connection.
# Display IPv6 BGP routing table information on Device A.
[ DeviceA ] display bgp routing-table ipv6
340
Total number of routes: 4
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
* >e Network : 9:: PrefixLen : 64
NextHop : 10::1 LocPrf :
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: 65009i
* > Network : 10:: PrefixLen : 64
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: i
* e Network : 10:: PrefixLen : 64
NextHop : 10::1 LocPrf :
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: 65009i
* > Network : 50:: PrefixLen : 64
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: i
The output shows that Device A has learned routing information of AS 65009.
# Display IPv6 BGP routing table information on Device C.
[ DeviceC ] display bgp routing-table ipv6
Total number of routes: 4
BGP local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
* > Network : 9:: PrefixLen : 64
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: i
341
* i Network : 9:: PrefixLen : 64
NextHop : 9::1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: i
* >i Network : 10:: PrefixLen : 64
NextHop : 9::1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: i
* >i Network : 50:: PrefixLen : 64
NextHop : 10::2 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: 65008i
The output shows that Device C has learned the route 50::/64.
# Verify that Device C can ping hosts on network 50::/64. (Details not shown.)
Troubleshooting BGP
State of the connection to a peer cannot become established
Symptom
The display bgp peer ipv4 unicast or display bgp peer ipv6 unicast command output shows that the state of the connection to a peer cannot become established.
Analysis
Solution
To become BGP peers, any two routers must establish a TCP connection using port 179 and exchange OPEN messages successfully.
1. To resolve the problem: a. Use the display current-configuration command to verify the current configuration, and verify that the peer's AS number is correct. b. Use the display bgp peer ipv4 unicast or display bgp peer ipv6 unicast command to verify that the peer's IP/IPv6 address is correct. c. If a loopback interface is used, verify that the loopback interface is specified with the peer connect-interface command. d. If the peer is a non-direct EBGP peer, verify that the peer ebgp-max-hop command is configured. e. If the peer ttl-security hops command is configured, verify that the command is configured on the peer. Verify that the hop-count values configured on them are greater than the number of hops between them. f. Verify that a valid route to the peer is available. g. Use the ping command to verify the connectivity to the peer.
342
h. Use the display tcp verbose or display ipv6 tcp verbose command to verify the TCP connection. i. Verify that no ACL rule is applied to disable TCP port 179.
2. If the problem persists, contact Hewlett Packard Enterprise Support.
343
Configuring large-scale BGP networks
Large-scale BGP network configuration tasks at a glance
To configure large-scale BGP networks, perform the following tasks:
•
Configuring BGP route dampening
•
•
Configuring BGP route reflection
•
Configuring BGP confederation settings
Configuring a BGP confederation
(Optional.) Configuring confederation compatibility
Configuring BGP route dampening
About this task
Route dampening enables BGP to not select unstable routes as optimal routes.
Restrictions and guidelines
This feature applies to EBGP routes but not to IBGP routes.
If an EBGP peer goes down after you configure this feature, routes coming from the peer are dampened but not deleted.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure BGP route dampening. dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ] *
By default, BGP route dampening is not configured.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
344
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure IPv6 BGP route dampening. dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ] *
By default, IPv6 BGP route dampening is not configured.
Configuring BGP communities
About this task
By default, a router does not advertise the COMMUNITY or extended community attribute to its peers or peer groups. When the router receives a route carrying the COMMUNITY or extended community attribute, it removes the attribute before advertising the route to other peers or peer groups.
Perform this task to enable a router to advertise the COMMUNITY or extended community attribute to its peers for route filtering and control. You can also use a routing policy to add or modify the
COMMUNITY or extended community attribute for specific routes. For more information about
routing policy, see " Configuring routing policies ."
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Advertise the COMMUNITY attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-community
By default, the COMMUNITY attribute is not advertised.
4. Advertise the extended community attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-ext-community
345
By default, the extended community attribute is not advertised.
5. (Optional.) Apply a routing policy to routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name export
By default, no routing policy is applied.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Advertise the COMMUNITY attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-community
By default, the COMMUNITY attribute is not advertised.
4. Advertise the extended community attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-ext-community
By default, the extended community attribute is not advertised.
5. (Optional.) Apply a routing policy to routes advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-policy route-policy-name export
By default, no routing policy is applied.
Configuring BGP route reflection
Configuring a BGP route reflector
About this task
Perform this task to configure a BGP route reflector and its clients. The route reflector and its clients automatically form a cluster identified by the router ID of the route reflector. The route reflector forwards route updates among its clients.
To improve availability, you can specify multiple route reflectors for a cluster. The route reflectors in the cluster must have the same cluster ID to avoid routing loops.
When a route reflector connects to multiple clusters, you can configure different cluster IDs for different peers or peer groups.
You only need to configure BGP route reflection on the device that acts as a route reflector. Other devices do not need to know the role of the local device in route reflection.
346
After you configure a device as a route reflector, it advertises routes as follows:
•
Advertises routes received from a non-client IBGP peer to all clients.
•
Advertises routes received from an IBGP peer that acts as a client to all peers.
•
Advertises routes received from an EBGP peer to all peers.
Restrictions and guidelines
If you do not configure the peer cluster-id command for a peer or peer group, the peer or peer group uses the cluster ID configured by the reflector cluster-id command.
For a peer or peer group, the cluster ID configured by the peer cluster-id command takes precedence over the cluster ID configured by the reflector cluster-id command.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure the cluster ID of the route reflector for a peer or peer group.
peer { group-name | ipv4-address [ mask-length ] } cluster-id cluster-id
By default, the cluster ID of the route reflector is not configured for a peer or peer group.
4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
This command is available only in BGP instance view.
5. Configure the router as a route reflector and specify a peer or peer group as its client. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } reflect-client
By default, no route reflector or client is configured.
6. (Optional.) Enable route reflection between clients. reflect between-clients
By default, route reflection between clients is enabled.
7. (Optional.) Configure the cluster ID of the route reflector. reflector cluster-id { cluster-id | ipv4-address }
By default, a route reflector uses its own router ID as the cluster ID.
8. (Optional.) Enable the route reflector to change the attributes of routes to be reflected. reflect change-path-attribute
347
By default, the route reflector cannot change the attributes of routes to be reflected.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure the cluster ID of the route reflector for a peer or peer group.
peer { group-name | ipv6-address [ prefix-length ] } cluster-id cluster-id
By default, the cluster ID of the route reflector is not configured for a peer or peer group.
4. Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
This command is available only in BGP instance view.
5. Configure the router as a route reflector and specify a peer or peer group as its client. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } reflect-client
By default, no route reflector or client is configured.
6. (Optional.) Enable route reflection between clients. reflect between-clients
By default, route reflection between clients is enabled.
7. (Optional.) Configure the cluster ID of the route reflector. reflector cluster-id { cluster-id | ipv4-address }
By default, a route reflector uses its own router ID as the cluster ID.
8. (Optional.) Enable the route reflector to change the attributes of routes to be reflected. reflect change-path-attribute
By default, the route reflector cannot change the attributes of routes to be reflected.
Ignoring the ORIGINATOR_ID attribute
About this task
By default, BGP drops incoming route updates whose ORIGINATOR_ID attribute is the same as the local router ID. Some special networks such as firewall networks require BGP to accept such route updates. To meet the requirement, you must configure BGP to ignore the ORIGINATOR_ID attribute.
Restrictions and guidelines
Make sure this command does not result in a routing loop.
After you configure this feature, BGP also ignores the CLUSTER_LIST attribute.
Procedure (IPv4 peers)
1. Enter system view. system-view
348
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Ignore the ORIGINATOR_ID attribute. peer { group-name | ipv4-address [ mask-length ] } ignore-originatorid
By default, BGP does not ignore the ORIGINATOR_ID attribute.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Ignore the ORIGINATOR_ID attribute. peer { group-name | ipv6-address [ prefix-length ] } ignore-originatorid
By default, BGP does not ignore the ORIGINATOR_ID attribute.
Configuring BGP confederation settings
About BGP confederation
BGP confederation provides another way to reduce IBGP connections in an AS.
A confederation contains sub-ASs. In each sub-AS, IBGP peers are fully meshed. Sub-ASs establish
EBGP connections in between.
Configuring a BGP confederation
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Configure a confederation ID.
confederation id as-number
By default, no confederation ID is configured.
From an outsider's perspective, the sub-ASs of the confederation is a single AS, which is identified by the confederation ID.
4. Specify confederation peer sub-ASs in the confederation. confederation peer-as as-number-list
349
By default, no confederation peer sub-ASs are specified.
A confederation can contain a maximum of 32 sub-ASs. The AS number of a sub-AS is effective only in the confederation.
If the router needs to establish EBGP connections to other sub-ASs, you must specify the peering sub-ASs in the confederation.
Configuring confederation compatibility
About this task
If any routers in the confederation do not comply with RFC 3065, enable confederation compatibility to allow the router to work with those routers.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable confederation compatibility. confederation nonstandard
By default, confederation compatibility is disabled.
Verifying and maintaining large-scale BGP network configuration
Verifying BGP configuration and running status (IPv4 unicast address family)
Perform display tasks in any view.
•
Display BGP IPv4 unicast route dampening parameter information.
display bgp [ instance instance-name ] dampening parameter ipv4
[ unicast ] [ vpn-instance vpn-instance-name ]
•
Display BGP IPv4 unicast peer group information.
display bgp [ instance instance-name ] group ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ group-name group-name ]
•
Display information about a peer or peer group in BGP IPv4 unicast address family.
display bgp [ instance instance-name ] peer ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address mask-length |
{ ipv4-address | group-name group-name } log-info | [ ipv4-address ] verbose ] display bgp [ instance instance-name ] peer ipv4 [ unicast ]
[ ipv6-address prefix-length | ipv6-address log-info | [ ipv6-address ] verbose ]
•
Display dampened BGP IPv4 unicast route information.
display bgp [ instance instance-name ] routing-table dampened ipv4
[ unicast ] [ vpn-instance vpn-instance-name ]
350
Verifying BGP configuration and running status (IPv6 unicast address family)
Perform display tasks in any view.
•
Display BGP IPv6 unicast route dampening parameter information.
display bgp [ instance instance-name ] dampening parameter ipv6
[ unicast ] [ vpn-instance vpn-instance-name ]
•
Display BGP IPv6 unicast peer group information.
display bgp [ instance instance-name ] group ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ group-name group-name ]
•
Display information about a peer or peer group in BGP IPv6 unicast address family.
display bgp [ instance instance-name ] peer ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length |
{ ipv6-address | group-name group-name } log-info | [ ipv6-address ] verbose ]
display bgp [ instance instance-name ] peer ipv6 [ unicast ]
[ ipv4-address mask-length | ipv4-address log-info | [ ipv4-address ] verbose ]
•
Display dampened BGP IPv6 unicast route information.
display bgp [ instance instance-name ] routing-table dampened ipv6
[ unicast ] [ vpn-instance vpn-instance-name ]
Displaying and clearing BGP route flapping statistics
Displaying BGP route flapping statistics
Perform display tasks in any view.
•
Display BGP IPv4 unicast route flapping statistics.
display bgp [ instance instance-name ] routing-table flap-info ipv4
[ unicast ] [ vpn-instance vpn-instance-name ] [ ipv4-address
[ { mask-length | mask } [ longest-match ] ] | as-path-acl
{ as-path-acl-number | as-path-acl-name } ]
•
Display BGP IPv6 unicast route flapping statistics.
display bgp [ instance instance-name ] routing-table flap-info ipv6
[ unicast ] [ vpn-instance vpn-instance-name ] [ ipv6-address
prefix-length | as-path-acl { as-path-acl-number | as-path-acl-name } ]
Clearing BGP route flapping statistics
Perform clear tasks in user view.
•
Clear BGP IPv4 unicast route flapping statistics. reset bgp [ instance instance-name ] flap-info ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv4-address [ mask-length | mask ]
| as-path-acl as-path-acl-number | peer ipv4-address [ mask-length ] ]
•
Clear BGP IPv6 unicast route flapping statistics. reset bgp [ instance instance-name ] flap-info ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length | as-path-acl { as-path-acl-number | as-path-acl-name } | peer ipv6-address [ prefix-length ] ]
351
Large-scale BGP network configuration examples
Example: Configuring BGP communities
Network configuration
As shown in
Figure 80 , Device B establishes EBGP connections to Device A and Device C.
Configure NO_EXPORT community attribute on Device A so that AS 20 does not advertise routes received from AS 10 to any other AS.
Figure 80 Network diagram
Procedure
HGE1/0/2
200.1.2.1/24
Loop0
1.1.1.1/32
HGE1/0/1
9.1.1.1/24
AS 10
Device A
EBGP
AS 20
Loop0
2.2.2.2/32
HGE1/0/1
200.1.2.2/24
HGE1/0/2
200.1.3.1/24 EBGP
HGE1/0/1
200.1.3.2/24
Device B
Loop0
3.3.3.3/32
Device C
AS 30
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure EBGP connections:
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 10
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 200.1.2.2 as-number 20
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 200.1.2.2 enable
[DeviceA-bgp-default-ipv4] network 9.1.1.0 255.255.255.0
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 20
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 200.1.2.1 as-number 10
[DeviceB-bgp-default] peer 200.1.3.2 as-number 30
[DeviceB-bgp-default] address-family ipv4 unicast
352
[DeviceB-bgp-default-ipv4] peer 200.1.2.1 enable
[DeviceB-bgp-default-ipv4] peer 200.1.3.2 enable
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 30
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 200.1.3.1 as-number 20
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 200.1.3.1 enable
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
# Display the BGP route 9.1.1.0 on Device B.
[DeviceB] display bgp routing-table ipv4 9.1.1.0
BGP local router ID: 2.2.2.2
Local AS number: 20
Paths: 1 available, 1 best
BGP routing table information of 9.1.1.0/24:
From : 200.1.2.1 (1.1.1.1)
Rely nexthop : 200.1.2.1
Original nexthop: 200.1.2.1
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
AS-path : 10
Origin : igp
Attribute value : pref-val 0
State : valid, external, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
VPN-Peer UserID : N/A
DSCP : N/A
EXP : N/A
# Display advertisement information for the route 9.1.1.0 on Device B.
[DeviceB] display bgp routing-table ipv4 9.1.1.0 advertise-info
BGP local router ID: 2.2.2.2
Local AS number: 20
Paths: 1 best
BGP routing table information of 9.1.1.0/24:
Advertised to peers (1 in total):
353
200.1.3.2
The output shows that Device B can advertise the route with the destination 9.1.1.0/24 to other
ASs through BGP.
# Display the BGP routing table on Device C.
[DeviceC] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 3.3.3.3
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 9.1.1.0/24 200.1.3.1 0 20 10i
Device C has learned the route to the destination 9.1.1.0/24 from Device B.
3. Configure the BGP COMMUNITY attribute:
# Configure a routing policy.
[DeviceA] route-policy comm_policy permit node 0
[DeviceA-route-policy-comm_policy-0] apply community no-export
[DeviceA-route-policy-comm_policy-0] quit
# Apply the routing policy.
[DeviceA] bgp 10
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 200.1.2.2 route-policy comm_policy export
[DeviceA-bgp-default-ipv4] peer 200.1.2.2 advertise-community
Verifying the configuration
# Display the BGP route 9.1.1.0 on Device B.
[DeviceB] display bgp routing-table ipv4 9.1.1.0
BGP local router ID: 2.2.2.2
Local AS number: 20
Paths: 1 available, 1 best
BGP routing table information of 9.1.1.0/24:
From : 200.1.2.1 (1.1.1.1)
Rely nexthop : 200.1.2.1
Original nexthop: 200.1.2.1
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
Community : No-Export
AS-path : 10
Origin : igp
354
Attribute value : pref-val 0
State : valid, external, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
VPN-Peer UserID : N/A
DSCP : N/A
EXP : N/A
# Display advertisement information for the route 9.1.1.0 on Device B.
[DeviceB] display bgp routing-table ipv4 9.1.1.0 advertise-info
BGP local router ID: 2.2.2.2
Local AS number: 20
Paths: 1 best
BGP routing table information of 9.1.1.0/24:
Not advertised to any peers yet
# Display the BGP routing table on Device C.
[DeviceC] display bgp routing-table ipv4
Total number of routes: 0
The output shows that BGP has not learned any route.
Example: Configuring BGP route reflector
Network configuration
As shown in Figure 81 , all devices run BGP. Run EBGP between Device A and Device B, run IBGP
between Device C and Device B, and between Device C and Device D.
Configure Device C as a route reflector with clients Device B and D to allow Device D to learn route
20.0.0.0/8 from Device C.
Figure 81 Network diagram
HGE1/0/1
20.1.1.1/8
Loop0
1.1.1.1/32
HGE1/0/2
192.1.1.1/24
Device A
Loop0
3.3.3.3/32
Route reflector
HGE1/0/1
193.1.1.1/24
Device C
HGE1/0/2
194.1.1.1/24
HGE1/0/1
192.1.1.2/24
Loop0
2.2.2.2/32
HGE1/0/2
193.1.1.2/24
HGE1/0/1
194.1.1.2/24
Loop0
4.4.4.4/32
AS 100 AS 200
Device B Device D
355
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces and configure OSPF in AS 200. (Details not shown.)
2. Configure BGP connections:
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 100
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 192.1.1.2 as-number 200
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 192.1.1.2 enable
# Inject network 20.0.0.0/8 to the BGP routing table.
[DeviceA-bgp-default-ipv4] network 20.0.0.0
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 200
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 192.1.1.1 as-number 100
[DeviceB-bgp-default] peer 193.1.1.1 as-number 200
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 192.1.1.1 enable
[DeviceB-bgp-default-ipv4] peer 193.1.1.1 enable
[DeviceB-bgp-default-ipv4] peer 193.1.1.1 next-hop-local
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 193.1.1.2 as-number 200
[DeviceC-bgp-default] peer 194.1.1.2 as-number 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 193.1.1.2 enable
[DeviceC-bgp-default-ipv4] peer 194.1.1.2 enable
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] bgp 200
[DeviceD-bgp-default] router-id 4.4.4.4
[DeviceD-bgp-default] peer 194.1.1.1 as-number 200
[DeviceD-bgp-default] address-family ipv4 unicast
356
[DeviceD-bgp-default-ipv4] peer 194.1.1.1 enable
[DeviceD-bgp-default-ipv4] quit
[DeviceD-bgp-default] quit
3. Configure Device C as the route reflector.
[DeviceC] bgp 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 193.1.1.2 reflect-client
[DeviceC-bgp-default-ipv4] peer 194.1.1.2 reflect-client
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
Verifying the configuration
# Display the BGP routing table on Device B.
[DeviceB] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 20.0.0.0/8 192.1.1.1 0 0 100i
# Display the BGP routing table on Device D.
[DeviceD] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 4.4.4.4
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 20.0.0.0/8 193.1.1.2 0 100 0 100i
The output shows that Device D has learned the route 20.0.0.0/8 from Device C.
Example: Configuring BGP confederation
Network configuration
As shown in Figure 82 , split AS 200 into three sub-ASs (AS 65001, AS 65002, and AS 65003) to
reduce IBGP connections. Devices in AS 65001 are fully meshed.
357
Figure 82 Network diagram
Device B
Device C
HGE1/0/1
Device F
HGE1/0/2
HGE1/0/1 AS 65002
HGE1/0/1
AS 65003
AS 100
HGE1/0/5
HGE1/0/4
Device A
HGE1/0/3
HGE1/0/1
HGE1/0/2
HGE1/0/2
HGE1/0/1
HGE1/0/2
Device D
AS 65001
HGE1/0/1
Device E
AS 200
Table 21 Interface and IP address assignment
Device
Device A
Device B
Device C
Procedure
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/3
HGE1/0/4
HGE1/0/5
HGE1/0/1
HGE1/0/1
IP address
10.1.2.1/24
10.1.3.1/24
10.1.4.1/24
200.1.1.1/24
10.1.1.1/24
10.1.1.2/24
10.1.2.2/24
Device
Device D
Device E
Device F
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
IP address
10.1.5.1/24
10.1.3.2/24
10.1.5.2/24
10.1.4.2/24
9.1.1.1/24
200.1.1.2/24
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure the BGP confederation:
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 65001
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] confederation id 200
[DeviceA-bgp-default] confederation peer-as 65002 65003
[DeviceA-bgp-default] peer 10.1.1.2 as-number 65002
[DeviceA-bgp-default] peer 10.1.2.2 as-number 65003
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 10.1.1.2 enable
[DeviceA-bgp-default-ipv4] peer 10.1.2.2 enable
[DeviceA-bgp-default-ipv4] peer 10.1.1.2 next-hop-local
358
[DeviceA-bgp-default-ipv4] peer 10.1.2.2 next-hop-local
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 65002
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] confederation id 200
[DeviceB-bgp-default] confederation peer-as 65001 65003
[DeviceB-bgp-default] peer 10.1.1.1 as-number 65001
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 10.1.1.1 enable
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 65003
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] confederation id 200
[DeviceC-bgp-default] confederation peer-as 65001 65002
[DeviceC-bgp-default] peer 10.1.2.1 as-number 65001
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 10.1.2.1 enable
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
3. Configure IBGP connections in AS65001:
# Configure Device A.
[DeviceA] bgp 65001
[DeviceA-bgp-default] peer 10.1.3.2 as-number 65001
[DeviceA-bgp-default] peer 10.1.4.2 as-number 65001
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 10.1.3.2 enable
[DeviceA-bgp-default-ipv4] peer 10.1.4.2 enable
[DeviceA-bgp-default-ipv4] peer 10.1.3.2 next-hop-local
[DeviceA-bgp-default-ipv4] peer 10.1.4.2 next-hop-local
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] bgp 65001
[DeviceD-bgp-default] router-id 4.4.4.4
[DeviceD-bgp-default] confederation id 200
[DeviceD-bgp-default] peer 10.1.3.1 as-number 65001
[DeviceD-bgp-default] peer 10.1.5.2 as-number 65001
[DeviceD-bgp-default] address-family ipv4 unicast
[DeviceD-bgp-default-ipv4] peer 10.1.3.1 enable
[DeviceD-bgp-default-ipv4] peer 10.1.5.2 enable
[DeviceD-bgp-default-ipv4] quit
359
[DeviceD-bgp-default] quit
# Configure Device E.
<DeviceE> system-view
[DeviceE] bgp 65001
[DeviceE-bgp-default] router-id 5.5.5.5
[DeviceE-bgp-default] confederation id 200
[DeviceE-bgp-default] peer 10.1.4.1 as-number 65001
[DeviceE-bgp-default] peer 10.1.5.1 as-number 65001
[DeviceE-bgp-default] address-family ipv4 unicast
[DeviceE-bgp-default-ipv4] peer 10.1.4.1 enable
[DeviceE-bgp-default-ipv4] peer 10.1.5.1 enable
[DeviceE-bgp-default-ipv4] quit
[DeviceE-bgp-default] quit
4. Configure the EBGP connection between AS 100 and AS 200:
# Configure Device A.
[DeviceA] bgp 65001
[DeviceA-bgp-default] peer 200.1.1.2 as-number 100
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 200.1.1.2 enable
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device F.
<DeviceF> system-view
[DeviceF] bgp 100
[DeviceF-bgp-default] router-id 6.6.6.6
[DeviceF-bgp-default] peer 200.1.1.1 as-number 200
[DeviceF-bgp-default] address-family ipv4 unicast
[DeviceF-bgp-default-ipv4] peer 200.1.1.1 enable
[DeviceF-bgp-default-ipv4] network 9.1.1.0 255.255.255.0
[DeviceF-bgp-default-ipv4] quit
[DeviceF-bgp-default] quit
Verifying the configuration
# Display the BGP routing table on Device B.
[DeviceB] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 9.1.1.0/24 10.1.1.1 0 100 0 (65001)
100i
360
[DeviceB] display bgp routing-table ipv4 9.1.1.0
BGP local router ID: 2.2.2.2
Local AS number: 65002
Paths: 1 available, 1 best
BGP routing table information of 9.1.1.0/24:
From : 10.1.1.1 (1.1.1.1)
Rely nexthop : 10.1.1.1
Original nexthop: 10.1.1.1
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
AS-path : (65001) 100
Origin : igp
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State : valid, external-confed, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
VPN-Peer UserID : N/A
DSCP : N/A
EXP : N/A
# Display the BGP routing table on Device D.
[DeviceD] display bgp routing-table ipv4
Total number of routes: 1
BGP local router ID is 4.4.4.4
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 9.1.1.0/24 10.1.3.1 0 100 0 100i
[DeviceD] display bgp routing-table ipv4 9.1.1.0
BGP local router ID: 4.4.4.4
Local AS number: 65001
Paths: 1 available, 1 best
BGP routing table information of 9.1.1.0/24:
From : 10.1.3.1 (1.1.1.1)
Rely nexthop : 10.1.3.1
361
Original nexthop: 10.1.3.1
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
AS-path : 100
Origin : igp
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State : valid, internal-confed, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
VPN-Peer UserID : N/A
DSCP : N/A
EXP : N/A
The output shows the following:
•
Device F can send route information to Device B and Device C through the confederation by establishing only an EBGP connection with Device A.
•
Device B and Device D are in the same confederation, but belong to different sub-ASs. They obtain external route information from Device A and generate identical BGP route entries although they have no direct connection in between.
362
Controlling BGP path selection
BGP path selection control tasks at a glance
By configuring BGP path attributes, you can control BGP path selection.
To control BGP path selection, perform the following tasks:
1.
Configuring preferences for BGP routes
2.
Configuring the NEXT_HOP attribute
Configuring a device to set itself as the next hop for routes sent to a peer or peer group
Advertising only the global unicast address in the NEXT_HOP attribute
3.
Setting a preferred value for received routes
4.
Configuring the default local preference
5.
Configuring the AS_PATH attribute
Permitting local AS number to appear in routes from a peer or peer group
Ignoring the AS_PATH attribute during optimal route selection
Advertising a fake AS number to a peer or peer group
Configuring AS number substitution
Removing private AS numbers from sent updates
Ignoring the first AS number of EBGP route updates
Setting an AS number quantity threshold
6.
Configuring the default MED value
Enabling MED comparison for routes from different ASs
Enabling MED comparison for routes on a per-AS basis
Enabling MED comparison for routes from confederation peers
7.
Configuring the AIGP attribute
8.
Ignoring IGP metrics during optimal route selection
9.
Ignoring router IDs during optimal route selection
10.
Configuring the next hop type selection rule for optimal route selection
Permitting BGP routes with only tunnel next hops to participate in optimal route selection
Preferring BGP routes of a specific next hop type during optimal route selection
Configuring preferences for BGP routes
About this task
Routing protocols each have a default preference. If they find multiple routes destined for the same network, the route found by the routing protocol with the highest preference is selected as the optimal route.
You can use the preference command to modify preferences for EBGP, IBGP, and local BGP routes, or use a routing policy to set a preference for matching routes. For routes not matching the routing policy, the default preference applies.
If a device has an EBGP route and a local BGP route to reach the same destination, it does not select the EBGP route because the EBGP route has a lower preference than the local BGP route by default.
363
You can use the network short-cut command to configure the EBGP route as a shortcut route that has the same preference as the local BGP route. The EBGP route will more likely become the optimal route.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure preferences for EBGP, IBGP, and local BGP routes. preference { external-preference internal-preference local-preference | route-policy route-policy-name }
By default, the preferences for EBGP, IBGP, and local BGP routes are 255, 255, and 130, respectively.
4. (Optional.) Configure an EBGP route as a shortcut route. network ipv4-address [ mask-length | mask ] short-cut
By default, an EBGP route has a preference of 255.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure preferences for EBGP, IBGP, and local BGP routes. preference { external-preference internal-preference local-preference | route-policy route-policy-name }
By default, the preferences for EBGP, IBGP, and local BGP routes are 255, 255, and 130, respectively.
4. (Optional.) Configure an EBGP route as a shortcut route. network ipv6-address prefix-length short-cut
By default, an EBGP route has a preference of 255.
364
Configuring the NEXT_HOP attribute
Configuring a device to set itself as the next hop for routes sent to a peer or peer group
About this task
By default, a BGP router does not set itself as the next hop for routes advertised to an IBGP peer or peer group. In some cases, however, you must configure the advertising router as the next hop to ensure that the BGP peer can find the correct next hop.
For example, as shown in Figure 83 , Router A and Router B establish an EBGP neighbor
relationship, and Router B and Router C establish an IBGP neighbor relationship. If Router C has no route destined for IP address 1.1.1.1/24, you must configure Router B to set itself 3.1.1.1/24 as the next hop for the network 2.1.1.1/24 advertised to Router C.
Figure 83 NEXT_HOP attribute configuration
AS 100 AS 200
2.1.1.1/24
Router A
1.1.1.1/24 1.1.1.2/24
EBGP
Router B
3.1.1.1/24 3.1.1.2/24
IBGP
Router C
If a BGP router has two peers on a broadcast network, it does not set itself as the next hop for routes
sent to an EBGP peer by default. As shown in Figure 84 , Router A and Router B establish an EBGP
neighbor relationship, and Router B and Router C establish an IBGP neighbor relationship. They are on the same broadcast network 1.1.1.0/24. When Router B sends EBGP routes to Router A, it does not set itself as the next hop by default. However, you can configure Router B to set it (1.1.1.2/24) as the next hop for routes sent to Router A by using the peer next-hop-local command as needed.
Figure 84 NEXT_HOP attribute configuration
AS 100
Router A
1.1.1.1/24
1.1.1.2/24
1.1.1.3/24
Router B
Router C
AS 200
Restrictions and guidelines
If you have configured BGP load balancing, the router sets itself as the next hop for routes sent to an
IBGP peer or peer group regardless of whether the peer next-hop-local command is configured.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
365
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Specify the router as the next hop for routes sent to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } next-hop-local
By default, the router sets itself as the next hop for routes sent to an EBGP peer or peer group.
However, it does not set itself as the next hop for routes sent to an IBGP peer or peer group.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Specify the router as the next hop for routes sent to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } next-hop-local
By default, the router sets itself as the next hop for routes sent to an EBGP peer or peer group.
However, it does not set itself as the next hop for routes sent to an IBGP peer or peer group.
Advertising only the global unicast address in the
NEXT_HOP attribute
About this task
An IPv6 peer might fail to learn routes if it cannot parse a route update that contains both the link-local address and the global unicast address. To resolve this issue, perform this task to enable the local device to advertise only the global unicast address in the NEXT_HOP attribute to its IPv6 peers.
Restrictions and guidelines
This feature might not apply to EBGP peers established through directly connected broadcast interfaces. If the next hop of the advertised route and the directly connected broadcast interfaces belong to the same subnet, this feature does not take effect.
Procedure (IPv4 unicast address family)
1. Enter system view.
366
system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable the device to advertise only the global unicast address in the NEXT_HOP attribute to its
IPv6 peers. nexthop global-address-only
By default, the local device with a link-local address advertises both the link-local address and the global unicast address in the NEXT_HOP attribute to IPv6 BGP peers.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable the device to advertise only the global unicast address in the NEXT_HOP attribute to its
IPv6 peers. nexthop global-address-only
By default, the local device with a link-local address advertises both the link-local address and the global unicast address in the NEXT_HOP attribute to IPv6 BGP peers.
Setting a preferred value for received routes
About this task
Perform this task to set a preferred value for specific routes to control BGP path selection.
Among multiple routes that have the same destination/mask and are learned from different peers, the one with the greatest preferred value is selected as the optimal route.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
367
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Set a preferred value for routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } preferred-value value
By default, the preferred value is 0 for routes received from a peer or peer group.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Set a preferred value for routes received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } preferred-value value
By default, the preferred value is 0 for routes received from a peer or peer group.
Configuring the default local preference
About this task
The local preference is used to determine the optimal route for traffic leaving the local AS. When a
BGP router obtains from several IBGP peers multiple routes to the same destination, but with different next hops, it selects the route with the highest local preference as the optimal route.
This task allows you to specify the default local preference for routes sent to IBGP peers.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
368
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure the default local preference. default local-preference value
The default local preference is 100.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure the default local preference. default local-preference value
The default local preference is 100.
Configuring the AS_PATH attribute
Permitting local AS number to appear in routes from a peer or peer group
About this task
In general, BGP checks whether the AS_PATH attribute of a route from a peer contains the local AS number. If yes, it discards the route to avoid routing loops.
In certain network environments (for example, a Hub&Spoke network in MPLS L3VPN), however, the AS_PATH attribute of a route from a peer must be allowed to contain the local AS number.
Otherwise, the route cannot be advertised correctly.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ]
369
address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Permit the local AS number to appear in routes from a peer or peer group and set the appearance times. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } allow-as-loop [ number ]
By default, the local AS number is not allowed in routes from a peer or peer group.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Permit the local AS number to appear in routes from a peer or peer group and set the appearance times. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } allow-as-loop [ number ]
By default, the local AS number is not allowed in routes from a peer or peer group.
Ignoring the AS_PATH attribute during optimal route selection
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to ignore the AS_PATH attribute during optimal route selection. bestroute as-path-neglect
By default, BGP includes the AS_PATH attribute in optimal route selection.
370
Advertising a fake AS number to a peer or peer group
About this task
After you move a BGP router from an AS to another AS (from AS 2 to AS 3 for example), you have to modify the AS number of the router on all its EBGP peers. To avoid such modifications, you can configure the router to advertise a fake AS number 2 to its EBGP peers so that the EBGP peers still think that Router A is in AS 2.
Restrictions and guidelines
This command applies only to EBGP peers or EBGP peer groups.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Advertise a fake AS number to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } fake-as as-number
By default, no fake AS number is advertised to a peer or peer group.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Advertise a fake AS number to a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } fake-as as-number
By default, no fake AS number is advertised to a peer or peer group.
Configuring AS number substitution
About this task
To use EBGP between PE and CE in MPLS L3VPN, VPN sites in different geographical areas should have different AS numbers. Otherwise, BGP discards route updates containing the local AS number.
If two CEs connected to different PEs use the same AS number, you must configure AS number substitution on each PE. This substitution can replace the AS number in route updates originated by the remote CE as its own AS number before advertising them to the connected CE.
371
Figure 85 AS number substitution configuration (in an IPv4 network)
PE 1
AS 100
MPLS backbone
PE 2
EBGP_Update: 10.1.0.0/16
AS_PATH: 800
CE 1
VPNv4_Update: 10.1.0.0/16
RD: 100:1
AS_PATH: 800
CE 2
EBGP_Update: 10.1.0.0/16
AS_PATH: 100, 100
AS 800 AS 800
As shown in Figure 85 , CE 1 and CE 2 use the same AS number 800. To ensure bidirectional
communication between the two sites, configure AS number substitution on PE 2. PE 2 replaces AS
800 with AS 100 for the BGP route update originated from CE 1 before advertising it to CE 2. Perform the same configuration on PE 1.
Restrictions and guidelines
Do not configure AS number substitution in normal circumstances. Otherwise, routing loops might occur.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure AS number substitution for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } substitute-as
By default, AS number substitution is not configured.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure AS number substitution for a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } substitute-as
By default, AS number substitution is not configured.
372
Removing private AS numbers from sent updates
About this task
Private AS numbers are typically used in test networks, and should not be transmitted in public networks. The range of private AS numbers is from 64512 to 65535.
Perform this task to enable BGP to remove private AS numbers from the AS_PATH attribute of updates sent to a peer or peer group.
Restrictions and guidelines
This feature is applicable only to EBGP peers or peer groups.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure BGP to remove private AS numbers from the AS_PATH attribute of updates sent to an EBGP peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } public-as-only
By default, BGP updates sent to an EBGP peer or peer group can carry both public and private
AS numbers.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure BGP to remove private AS numbers from the AS_PATH attribute of updates sent to an EBGP peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } public-as-only
373
By default, BGP updates sent to an EBGP peer or peer group can carry both public and private
AS numbers.
Ignoring the first AS number of EBGP route updates
About this task
By default, BGP checks the first AS number of an EBGP-learned route update. If the first AS number is neither the AS number of the BGP peer nor a private AS number, the BGP router disconnects the
BGP session to the peer.
Ignoring the first AS number of EBGP route updates
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Configure BGP to ignore the first AS number of EBGP route updates. ignore-first-as
By default, BGP checks the first AS number of EBGP-learned route updates.
Ignoring the first AS number of EBGP route updates received from a peer or peer group (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to ignore the first AS number of EBGP route updates received from a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } ignore-first-as
By default, BGP checks the first AS number of EBGP-learned route updates.
Ignoring the first AS number of EBGP route updates received from a peer or peer group (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to ignore the first AS number of EBGP route updates received from a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } ignore-first-as
374
By default, BGP checks the first AS number of EBGP-learned route updates.
Setting an AS number quantity threshold
About this task
Perform this task to enable BGP to filter routes based on the quantity of AS numbers contained in the
AS_PATH attribute. BGP will discard incoming and outgoing routes, and withdraw routes that have been advertised if they exceed the specified quantity threshold.
Restrictions and guidelines
This feature does not take effect on routes that have been received or on local summary routes.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Set an AS number quantity threshold. as-path-limit [ as-numbers ]
By default, no AS number quantity threshold is configured.
Configuring the MED attribute
About the MED attribute
BGP uses MED to determine the optimal route for traffic going into an AS. When a BGP router obtains multiple routes with the same destination but with different next hops, it selects the route with the smallest MED value as the optimal route if other conditions are the same.
Configuring the default MED value
Configuring the default MED value (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view: bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure the default MED value.
default med med-value
The default MED value is 0.
375
Configuring the default MED value (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view: bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view: bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure the default MED value.
default med med-value
The default MED value is 0.
Enabling MED comparison for routes from different ASs
About this task
By default, BGP only compares the MEDs of routes from the same AS. This task enables BGP to compare the MEDs of routes from different ASs.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable MED comparison for routes from different ASs. compare-different-as-med
By default, MED comparison for routes from different ASs is disabled.
Enabling MED comparison for routes on a per-AS basis
About this task
This task enables BGP to compare the MEDs of routes from an AS.
376
Figure 86 Route selection based on MED (in an IPv4 network)
AS 400
Device E
10.0.0.0
AS 200
Loop0
3.3.3.3/32
Device A
Interface A1
13.1.1.2/24
Device C
Loop0
1.1.1.1/32
Interface C1
11.1.1.2/24
AS 300
Device B
Interface B1
12.1.1.2/24
Loop0
2.2.2.2/32
Interface D1
Interface D3 Interface D2
AS 100
Device D
As shown in Figure 86 , Device D establishes indirect EBGP peer relationships with Device A, Device
B, and Device C, and learns addresses 1.1.1.1/32, 2.2.2.2/32, and 3.3.3.3/32 through OSPF. The following output shows the routing information on Device D.
Destination/Mask Proto Pre Cost NextHop Interface
1.1.1.1/32 O_INTRA 10 10 11.1.1.2 Interface D1
2.2.2.2/32 O_INTRA 10 20 12.1.1.2 Interface D2
3.3.3.3/32 O_INTRA 10 30 13.1.1.2 Interface D3
Device D learns network 10.0.0.0 from both Device A and Device B. Because the route learned from
Device B has a smaller IGP metric, the route is optimal. The following output shows the BGP routing table on Device D.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>e 10.0.0.0 2.2.2.2 50 0 300 400e
* e 3.3.3.3 50 0 200 400e
When Device D learns network 10.0.0.0 from Device C, it compares the route with the optimal route in its routing table. Because Device C and Device B reside in different ASs, BGP does not compare the MEDs of the two routes. The route from Device C has a smaller IGP metric than the route from
Device B, so the route from Device C becomes optimal. The following output shows the BGP routing table on Device D.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>e 10.0.0.0 1.1.1.1 60 0 200 400e
* e 10.0.0.0 2.2.2.2 50 0 300 400e
* e 3.3.3.3 50 0 200 400e
However, Device C and Device A reside in the same AS, and Device C has a greater MED, so network 10.0.0.0 learned from Device C should not be optimal.
To avoid this problem, you can configure the bestroute compare-med command to enable MED comparison for routes from the same AS on Device D. After that, Device D puts the routes received from each AS into a group, selects the route with the lowest MED from each group, and compares routes from different groups. Network 10.0.0.0 learned from Device B is the optimal route. The following output shows the BGP routing table on Device D.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>e 10.0.0.0 2.2.2.2 50 0 300 400e
377
* e 3.3.3.3 50 0 200 400e
* e 1.1.1.1 60 0 200 400e
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable MED comparison for routes on a per-AS basis. bestroute compare-med
By default, MED comparison for routes on a per-AS basis is disabled.
Enabling MED comparison for routes from confederation peers
About this task
This task enables BGP to compare the MEDs of routes received from confederation peers. However, if a route received from a confederation peer has an AS number that does not belong to the confederation, BGP does not compare the route with other routes. For example, a confederation has three AS numbers 65006, 65007, and 65009. BGP receives three routes from different confederation peers. The AS_PATH attributes of these routes are 65006 65009, 65007 65009, and 65008 65009, and the MED values of them are 2, 3, and 1. Because the third route's AS_PATH attribute contains
AS number 65008 that does not belong to the confederation, BGP does not compare it with other routes. As a result, the first route becomes the optimal route.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable MED comparison for routes from confederation peers. bestroute med-confederation
By default, MED comparison for routes from confederation peers is disabled.
Configuring the AIGP attribute
About this task
An Accumulated Interior Gateway Protocol (AIGP) administrative domain is a collection of multiple
ASs that run the same IGP under one administrative control. Within the domain, BGP accumulates
378
the IGP metrics all along the forwarding path for a route. Then, it uses the accumulated value as the
AIGP attribute for the route to implement metric-based route selection.
By default, BGP does not advertise the AIGP attribute to its peers or peer groups. When BGP receives a route carrying the AIGP attribute, it ignores and removes the attribute before advertising the route to other peers or peer groups. Perform this task to enable BGP to advertise the AIGP attribute to its peers or peer groups.
With this feature enabled, a router processes the AIGP attribute in a received route as follows:
•
If the router sets itself as the next hop for the route, it adds to the AIGP attribute value the IGP metric from itself to the original next hop and advertises the new AIGP attribute value.
•
If the router does not set itself as the next hop for the route, it does not change the AIGP attribute value.
BGP uses the AIGP attribute to select the optimal route as follows:
•
A route carrying the AIGP attribute takes precedence over a route not carrying the AIGP attribute.
•
A route that has a smaller computed AIGP attribute value has a higher priority.
When the AIGP attribute of a route changes, BGP sends a route update with the new AIGP attribute.
Restrictions and guidelines
As a best practice, do not configure the peer aigp command on border routers of an AIGP administrative domain.
When a router receives a route not carrying the AIGP attribute, it does not advertise the AIGP attribute to a peer or peer group if you configure only the peer aigp command. To enable the router to advertise the AIGP attribute, you must configure both the peer aigp and apply aigp commands. For information about the apply aigp
command, see " Configuring routing policies ."
Procedure (IPv4)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Execute the following commands in sequence to enter BGP IPv4 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure BGP to advertise the AIGP attribute to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } aigp
By default, BGP does not advertise the AIGP attribute to a peer or peer group and ignores the
AIGP attribute in routes received from the peer or peer group.
4. (Optional.) Replace the MED value with AIGP value in routes advertised to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } aigp send med
By default, BGP does not replace the MED value with AIGP value in routes advertised to a peer or peer group.
379
Use this command to send the AIGP attribute to a peer or peer group that does not support
AIGP.
Procedure (IPv6)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Execute the following commands in sequence to enter BGP IPv6 unicast address family view:
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure BGP to advertise the AIGP attribute to the specified peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } aigp
By default, BGP does not advertise the AIGP attribute to a peer or peer group and ignores the
AIGP attribute in routes received from the peer or peer group.
4. (Optional.) Replace the MED value with AIGP value in routes advertised to the specified peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } aigp send med
By default, BGP does not replace the MED value with AIGP value in routes advertised to a peer or peer group.
Use this command to send the AIGP attribute to a peer or peer group that does not support
AIGP.
Ignoring IGP metrics during optimal route selection
About this task
By default, BGP includes IGP metrics in optimal route selection. If multiple routes to the same destination are available, BGP selects the route with the smallest IGP metric as the optimal route.
Perform this task to enable BGP to ignore IGP metrics during optimal route selection.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to ignore IGP metrics during optimal route selection.
380
bestroute igp-metric-ignore
By default, BGP includes IGP metrics in optimal route selection.
Ignoring router IDs during optimal route selection
About this task
By default, BGP compares router IDs during optimal route selection. If multiple routes to the same destination are available, BGP selects the route with the smallest router ID as the optimal route.
Perform this task to enable BGP to ignore router IDs during optimal route selection.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to ignore router IDs during optimal route selection. bestroute router-id-ignore
By default, BGP compares router IDs during optimal route selection.
Configuring the next hop type selection rule for optimal route selection
About tunnel next hops
When a BGP route is iterated to a tunnel next hop, the tunnel can be one of the following:
•
Label swtiched path (LSP) or MPLS TE tunnel.
•
GRE or VXLAN tunnels.
•
SR-MPLS TE policy or SRv6 TE policy.
Each tunnel next hop has a unique tunnel ID. To view the tunnel next hops of BGP routes, see the
Rely tunnel IDs field in the output of the display bgp routing-table command.
Permitting BGP routes with only tunnel next hops to participate in optimal route selection
About this task
By default, BGP routes can participate in optimal route selection only when they have IP next hops.
In some scenarios, BGP routes might have tunnel next hops only and are considered unreachable.
To resolve this issue, perform this task to permit BGP routes that have only tunnel next hops to participate in optimal route selection.
381
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Permit BGP routes that have only tunnel next hops to participate in optimal route selection. bestroute nexthop-resolved tunnel
By default, BGP routes can participate in optimal route selection only when they have IP next hops.
Preferring BGP routes of a specific next hop type during optimal route selection
About this task
By default, the next hop type of BGP routes does not affect optimal route selection. To create the next hop type selection rule for optimal route selection, perform this task. BGP uses this rule to continue route selection if it fails to select an optimal route from routes received from EBGP peers. If BGP still fails route selection, it uses the router ID selection rule to select an optimal route.
For more information about BGP route selection rules, see BGP route selection in Basic BGP
Configuration .
Restrictions and guidelines
BGP routes that have only tunnel next hops cannot participate in optimal route selection even if you have performed this task. To resolve this issue, use the bestroute nexthop-resolved tunnel command.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Create the next hop type selection rule for optimal route selection. bestroute nexthop-type { ip | tunnel }
By default, the next hop type of BGP routes does not affect optimal route selection.
382
Verifying and maintaining BGP path selection control
To display BGP route attribute information, execute the following command in any view: display bgp [ instance instance-name ] paths [ as-regular-expression ]
BGP path selection control configuration examples
Example: Configuring BGP path selection
Network configuration
As shown in Figure 87 , all devices run BGP.
•
EBGP runs between Device A and Device B, and between Device A and Device C.
•
IBGP runs between Device B and Device D, and between Device D and Device C. OSPF is the
IGP protocol in AS 200.
Configure routing policies to make Device D give priority to the route 1.0.0.0/8 learned from Device
C.
Figure 87 Network diagram
AS 200
Procedure
AS 100
HGE1/0/1 HGE1/0/2
HGE1/0/1
HGE1/0/2
Device B
HGE1/0/2
HGE1/0/1
Device D HGE1/0/3
Device A
HGE1/0/1 HGE1/0/2
Device C
Table 22 Interface and IP address assignment
Device
Device A
Device B
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/3
HGE1/0/1
HGE1/0/2
IP address
1.0.0.1/8
192.1.1.1/24
193.1.1.1/24
192.1.1.2/24
194.1.1.2/24
Device
Device D
Device C
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
IP address
195.1.1.1/24
194.1.1.1/24
193.1.1.2/24
195.1.1.2/24
383
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF on Device B, Device C, and Device D:
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospf
[DeviceB-ospf] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] network 194.1.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ospf
[DeviceC-ospf] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 193.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] ospf
[DeviceD-ospf] area 0
[DeviceD-ospf-1-area-0.0.0.0] network 194.1.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[DeviceD-ospf-1-area-0.0.0.0] quit
[DeviceD-ospf-1] quit
3. Configure BGP connections:
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 100
[DeviceA-bgp-default] peer 192.1.1.2 as-number 200
[DeviceA-bgp-default] peer 193.1.1.2 as-number 200
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 192.1.1.2 enable
[DeviceA-bgp-default-ipv4] peer 193.1.1.2 enable
# Inject network 1.0.0.0/8 into the BGP routing table of Device A.
[DeviceA-bgp-default-ipv4] network 1.0.0.0 8
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
[DeviceB] bgp 200
[DeviceB-bgp-default] peer 192.1.1.1 as-number 100
[DeviceB-bgp-default] peer 194.1.1.1 as-number 200
384
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 192.1.1.1 enable
[DeviceB-bgp-default-ipv4] peer 194.1.1.1 enable
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C.
[DeviceC] bgp 200
[DeviceC-bgp-default] peer 193.1.1.1 as-number 100
[DeviceC-bgp-default] peer 195.1.1.1 as-number 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 193.1.1.1 enable
[DeviceC-bgp-default-ipv4] peer 195.1.1.1 enable
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
# Configure Device D.
[DeviceD] bgp 200
[DeviceD-bgp-default] peer 194.1.1.2 as-number 200
[DeviceD-bgp-default] peer 195.1.1.2 as-number 200
[DeviceD-bgp-default] address-family ipv4 unicast
[DeviceD-bgp-default-ipv4] peer 194.1.1.2 enable
[DeviceD-bgp-default-ipv4] peer 195.1.1.2 enable
[DeviceD-bgp-default-ipv4] quit
[DeviceD-bgp-default] quit
4. Configure local preference for the route 1.0.0.0/8 to make Device D give priority to the route learned from Device C:
# Define IPv4 basic ACL 2000 to permit the route 1.0.0.0/8 on Device C.
[DeviceC] acl basic 2000
[DeviceC-acl-ipv4-basic-2000] rule permit source 1.0.0.0 0.255.255.255
[DeviceC-acl-ipv4-basic-2000] quit
# Define routing policy localpref on Device C to set the local preference of route 1.0.0.0/8 to
200 (the default is 100).
[DeviceC] route-policy localpref permit node 10
[DeviceC-route-policy-localpref-10] if-match ip address acl 2000
[DeviceC-route-policy-localpref-10] apply local-preference 200
[DeviceC-route-policy-localpref-10] quit
# Apply the routing policy localpref to the route from the peer 193.1.1.1 on Device C.
[DeviceC] bgp 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 193.1.1.1 route-policy localpref import
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
# Display the BGP routing table on Device D.
[ DeviceD ] display bgp routing-table ipv4
Total number of routes: 2
BGP local router ID is 195.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
385
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 1.0.0.0/8 193.1.1.1 200 0 100i
* i 192.1.1.1 100 0 100i
The route 1.0.0.0/8 learned from Device C is the optimal route.
386
Tuning and optimizing BGP networks
BGP network tuning and optimization tasks at a glance
To tune and optimize BGP networks, perform the following tasks:
•
Establishing and resetting EBGP sessions
Enabling BGP to establish an EBGP session over multiple hops
Enabling immediate re-establishment of direct EBGP connections upon link failure
•
Enabling BGP ORF capabilities negotiation
•
Establishing, terminating, and resetting BGP sessions
Enabling 4-byte AS number suppression
Disabling BGP session establishment
•
Configuring BGP load balancing
•
Configuring the BGP Additional Paths feature
•
Configuring BGP optimal route selection delay
•
Setting the delay time for responding to recursive next hop changes
•
Configuring peer flap dampening
•
Protecting an EBGP peer when memory usage reaches level 2 threshold
•
Setting a DSCP value for outgoing BGP packets
•
Disabling route recursion policy control for routes received from a peer or peer group
•
Flushing the suboptimal BGP route to the RIB
•
Disabling MPLS local IFNET tunnel establishment
•
Configuring label allocation and path selection
Specifying a label allocation mode
Disabling optimal route selection for labeled routes without tunnel information
Enabling BGP to establish an EBGP session over multiple hops
About this task
To establish an EBGP session, two routers must have a direct physical link and use directly connected interfaces. If no direct link is available, you must use the peer ebgp-max-hop command to enable BGP to establish an EBGP session over multiple hops and specify the maximum hops.
Restrictions and guidelines
When the BGP GTSM feature is enabled, two peers can establish an EBGP session after passing
GTSM check, regardless of whether the maximum number of hops is reached.
Procedure (IPv4 peers)
1. Enter system view.
387
system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP to establish an EBGP session to an indirectly connected peer or peer group and specify the maximum hop count. peer { group-name | ipv4-address [ mask-length ] } ebgp-max-hop
[ hop-count ]
By default, BGP cannot establish an EBGP session to an indirectly connected peer or peer group.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP to establish an EBGP session to an indirectly connected peer or peer group and specify the maximum hop count. peer { group-name | ipv6-address [ prefix-length ] } ebgp-max-hop
[ hop-count ]
By default, BGP cannot establish an EBGP session to an indirectly connected peer or peer group.
Enabling immediate re-establishment of direct
EBGP connections upon link failure
About this task
By default, when the link to a directly connected EBGP peer goes down, the router does not re-establish a session to the peer until the hold time timer expires. This feature enables BGP to immediately recreate the session in that situation. When this feature is disabled, route flapping does not affect EBGP session state.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable immediate re-establishment of direct EBGP connections upon link failure. ebgp-interface-sensitive
388
By default, immediate re-establishment of direct EBGP connections is enabled.
Enabling BGP ORF capabilities negotiation
About BGP ORF
BGP Outbound Route Filtering (ORF) saves the system resources by reducing the route updates that are sent between BGP peers.
The BGP peers negotiate the ORF capabilities through Open messages. After completing the negotiation process, the BGP peers can exchange ORF information (local route reception filtering policy) through route refresh messages. Then, only routes that pass both the local route distribution filtering policy and the received route reception filtering policy can be advertised.
Restrictions and guidelines
You can enable the ORF information sending, receiving, or both sending and receiving capabilities on a BGP router. For two BGP peers to successfully negotiate the ORF capabilities, make sure one end has the sending capability and the other end has the receiving capability.
After you enable BGP ORF capabilities negotiation for a peer, the local device negotiates standard
ORF capabilities as defined in RFC with the peer. If the peer uses nonstandard ORF, you must also enable nonstandard ORF capabilities negotiation for the peer.
Enabling BGP ORF capabilities negotiation for a peer or peer group
Procedure (IPv4 unicast)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Enable BGP ORF capabilities negotiation for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } capability-advertise orf prefix-list { both | receive | send }
By default, BGP ORF capabilities negotiation is disabled for a peer or peer group.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view.
389
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Enable BGP ORF capabilities negotiation for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } capability-advertise orf prefix-list { both | receive | send }
By default, BGP ORF capabilities negotiation is disabled for a peer or peer group.
Enabling nonstandard BGP ORF capabilities negotiation for a peer or peer group
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable nonstandard BGP ORF capabilities negotiation for a peer or peer group. peer { group-name | ip-address [ mask-length ] | ipv6-address
[ prefix-length ] } capability-advertise orf non-standard
By default, nonstandard BGP ORF capabilities negotiation is disabled for a peer or peer group.
Verifying and maintaining BGP ORF
Perform displays tasks in any view.
•
Display the ORF prefix information received by an IPv4 unicast peer. display bgp [ instance instance-name ] peer ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] ipv4-address received prefix-list
•
Display the ORF prefix information received by an IPv6 unicast peer. display bgp [ instance instance-name ] peer ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] ipv6-address received prefix-list display bgp [ instance instance-name ] peer ipv6 [ unicast ] ipv4-address received prefix-list
Enabling 4-byte AS number suppression
About this task
BGP supports 4-byte AS numbers. The 4-byte AS number occupies four bytes, in the range of 1 to
4294967295. By default, a device sends an OPEN message to the peer device for session
390
establishment. The OPEN message indicates that the device supports 4-byte AS numbers. If the peer device supports 2-byte AS numbers instead of 4-byte AS numbers, the session cannot be established. To resolve this issue, enable the 4-byte AS number suppression feature. The device then sends an OPEN message to inform the peer that it does not support 4-byte AS numbers, so the
BGP session can be established.
Restrictions and guidelines
If the peer device supports 4-byte AS numbers, do not enable the 4-byte AS number suppression feature. Otherwise, the BGP session cannot be established.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable 4-byte AS number suppression. peer { group-name | ipv4-address [ mask-length ] } capability-advertise suppress-4-byte-as
By default, 4-byte AS number suppression is disabled.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable 4-byte AS number suppression. peer { group-name | ipv6-address [ prefix-length ] } capability-advertise suppress-4-byte-as
By default, 4-byte AS number suppression is disabled.
Disabling BGP session establishment
About disabling BGP session establishment
This task enables you to temporarily tear down BGP sessions to a peer/peer group or all peers/peer groups. You can perform network upgrade and maintenance without needing to delete and reconfigure the peers and peer groups. To recover the sessions, execute the undo peer ignore or undo ignore all-peers command.
If you specify the graceful keyword in the peer ignore command, BGP performs the following tasks:
391
•
Gracefully shuts down the session to the specified peer or peer group in the specified graceful shutdown period of time.
•
Advertises all routes to the specified peer or peer group and changes the attribute of the advertised routes to the specified value.
•
Advertises routes from the specified peer or peer group to other IBGP peers and peer groups and changes the attribute of the advertised routes to the specified value.
If you specify the graceful keyword in the ignore all-peers command, BGP performs the following tasks:
•
Gracefully shuts down the sessions to all peers and peer groups in the specified graceful shutdown period of time.
•
Advertises all routes to all peers and peer groups and changes the attribute of the advertised routes to the specified value.
Restrictions and guidelines
For a BGP peer or peer group, the configuration made by the peer ignore command takes precedence over the configuration made by the ignore all-peers command.
Disabling BGP session establishment with a peer or peer group (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Disable BGP session establishment with a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } ignore [ graceful graceful-time { community { community-number | aa:nn } |
local-preference preference | med med } * ]
By default, BGP can establish a session to a peer or peer group.
CAUTION:
•
If a session has been established to a peer, executing this command for the peer tears down the session and clears all related routing information.
•
If sessions have been established to a peer group, executing this command for the peer group tears down the sessions to all peers in the group and clears all related routing information.
Disabling BGP session establishment with a peer or peer group (IPv6 peers)
1. Enter system view.
392
system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Disable BGP session establishment with a peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } ignore [ graceful graceful-time { community { community-number | aa:nn } |
local-preference preference | med med } * ]
By default, BGP can establish a session to a peer or peer group.
CAUTION:
•
If a session has been established to a peer, executing this command for the peer tears down the session and clears all related routing information.
•
If sessions have been established to a peer group, executing this command for the peer group tears down the sessions to all peers in the group and clears all related routing information.
Disabling BGP session establishment with all peers or peer groups
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Disable BGP session establishment with all peers or peer groups. ignore all-peers [ graceful graceful-time { community
{ community-number | aa:nn } | local-preference preference | med med }
* ]
By default, BGP can establish sessions to all peers and peer groups.
CAUTION:
Executing this command tears down all existing sessions to peers and peer groups and clears all related routing information.
Configuring BGP soft-reset
About BGP soft-reset
After you modify the route selection policy, for example, modify the preferred value, you must reset
BGP sessions to apply the new policy. The reset operation tears down and re-establishes BGP sessions.
To avoid tearing down BGP sessions, you can use one of the following soft-reset methods to apply the new policy:
393
•
Enabling route refresh —The BGP router advertises a ROUTE-REFRESH message to the specified peer, and the peer resends its routing information to the router. After receiving the routing information, the router filters the routing information by using the new policy.
This method requires that both the local router and the peer support route refresh.
•
Saving updates —Use the peer keep-all-routes command to save all route updates from the specified peer. After modifying the route selection policy, filter routing information by using the new policy.
This method does not require that the local router and the peer support route refresh but it uses more memory resources to save routes.
•
Manual soft-reset —Use the refresh bgp command to enable BGP to send local routing information or advertise a ROUTE-REFRESH message to the specified peer. The peer then resends its routing information. After receiving the routing information, the router filters the routing information by using the new policy.
This method requires that both the local router and the peer support route refresh.
Enabling route refresh (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP route refresh for a peer or peer group.
Enable BGP route refresh for the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } capability-advertise route-refresh
Enable the BGP route refresh, multi-protocol extension, and 4-byte AS number features for the specified peer or peer group. undo peer { group-name | ipv4-address [ mask-length ] } capability-advertise conventional
By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled.
Enabling route refresh (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP route refresh for a peer or peer group.
394
Enable BGP route refresh for the specified peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } capability-advertise route-refresh
Enable the BGP route refresh, multi-protocol extension, and 4-byte AS number features for the specified peer or peer group. undo peer { group-name | ipv6-address [ prefix-length ] } capability-advertise conventional
By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled.
Saving updates (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Save all route updates from the peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } keep-all-routes
By default, route updates from peers and peer groups are not saved.
This command takes effect only for the routes received after this command is executed.
Saving updates (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view. bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Save all route updates from the peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } keep-all-routes
By default, route updates from peers and peer groups are not saved.
This command takes effect only for the routes received after this command is executed.
395
Configuring manual soft-reset (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP route refresh for a peer or peer group.
Enable BGP route refresh for the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } capability-advertise route-refresh
Enable the BGP route refresh, multi-protocol extension, and 4-byte AS number features for the specified peer or peer group. undo peer { group-name | ipv4-address [ mask-length ] } capability-advertise conventional
By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled.
4. Execute the quit command twice to return to user view. quit
5. Perform manual soft-reset. Choose one option as needed:
Perform manual soft-reset on IPv4 sessions in BGP IPv4 address family.
refresh bgp [ instance instance-name ] { ipv4-address [ mask-length ]
| all | external | group group-name | internal } { export | import } ipv4 [ unicast ] [ vpn-instance vpn-instance-name ]
Perform manual soft-reset on IPv6 sessions in BGP IPv4 address family.
refresh bgp [ instance instance-name ] { ipv6-address [ mask-length ]
| all | external | group group-name | internal } { export | import } ipv4 [ unicast ] [ vpn-instance vpn-instance-name ]
Configuring manual soft-reset (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BGP route refresh for a peer or peer group.
Enable BGP route refresh for the specified peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } capability-advertise route-refresh
396
Enable the BGP route refresh, multi-protocol extension, and 4-byte AS number features for the specified peer or peer group. undo peer { group-name | ipv6-address [ prefix-length ] } capability-advertise conventional
By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled.
4. Execute the quit command twice to return to user view. quit
5. Perform manual soft-reset. Choose one option as needed:
Perform manual soft-reset on IPv6 sessions in BGP IPv6 address family.
refresh bgp [ instance instance-name ] { ipv6-address
[ prefix-length ] | all | external | group group-name | internal }
{ export | import } ipv6 [ unicast ] [ vpn-instance vpn-instance-name ]
Perform manual soft-reset on IPv4 sessions in BGP IPv6 address family.
refresh bgp [ instance instance-name ] { ipv4-address [ mask-length ]
| all | external | group group-name | internal } { export | import } ipv6 [ unicast ] [ vpn-instance vpn-instance-name ]
Configuring BGP load balancing
About this task
Perform this task to specify the maximum number of BGP ECMP routes for load balancing.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. (Optional.) Enable BGP to ignore IGP metrics during optimal route selection. bestroute igp-metric-ignore
By default, BGP compares IGP metrics during optimal route selection, and selects the route with the smallest IGP metric as the optimal route.
BGP cannot use routes with different IGP metrics to implement load balancing. To resolve this issue, you can use this command.
4. Return to system view.
In BGP instance view, execute the quit command once.
In BGP-VPN instance view, execute the quit command twice.
5. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
397
Enter BGP-VPN IPv4 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
6. Specify the maximum number of BGP ECMP routes for load balancing. balance [ ebgp | eibgp | ibgp ] number
By default, load balancing is disabled.
7. (Optional.) Enable BGP to ignore the AS_PATH attribute when it implements load balancing. balance as-path-neglect
By default, BGP does not ignore the AS_PATH attribute when it implements load balancing.
8. (Optional.) Enable BGP to perform load balancing for routes that have different AS_PATH attributes of the same length. balance as-path-relax [ ebgp | ibgp ]
By default, BGP cannot perform load balancing for routes that have different AS_PATH attributes of the same length.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Execute the following commands in sequence to enter BGP-VPN instance view:
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. (Optional.) Enable BGP to ignore IGP metrics during optimal route selection. bestroute igp-metric-ignore
By default, BGP compares IGP metrics during optimal route selection, and selects the route with the smallest IGP metric as the optimal route.
BGP cannot use routes with different IGP metrics to implement load balancing. To resolve this issue, you can use this command.
4. Return to system view.
In BGP instance view, execute the quit command once.
In BGP-VPN instance view, execute the quit command twice.
5. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
6. Specify the maximum number of BGP ECMP routes for load balancing. balance [ ebgp | eibgp | ibgp ] number
By default, load balancing is disabled.
398
7. (Optional.) Enable BGP to ignore the AS_PATH attribute when it implements load balancing. balance as-path-neglect
By default, BGP does not ignore the AS_PATH attribute when it implements load balancing.
8. (Optional.) Enable BGP to perform load balancing for routes that have different AS_PATH attributes of the same length. balance as-path-relax [ ebgp | ibgp ]
By default, BGP cannot perform load balancing for routes that have different AS_PATH attributes of the same length.
Configuring the BGP Additional Paths feature
About this task
By default, BGP advertises only one optimal route. When the optimal route fails, traffic forwarding will be interrupted until route convergence completes.
The BGP Additional Paths (Add-Path) feature enables BGP to advertise multiple routes with the same prefix and different next hops to a peer or peer group. When the optimal route fails, the suboptimal route becomes the optimal route, which shortens the traffic interruption time.
You can enable the BGP additional path sending, receiving, or both sending and receiving capabilities on a BGP peer. For two BGP peers to successfully negotiate the Additional Paths capabilities, make sure one end has the sending capability and the other end has the receiving capability.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Configure the BGP Additional Paths capabilities. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } additional-paths { receive | send } *
By default, no BGP Additional Paths capabilities are configured.
4. Set the maximum number of Add-Path optimal routes that can be advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise additional-paths best number
By default, a maximum of one Add-Path optimal route can be advertised to a peer or peer group.
5. Set the maximum number of Add-Path optimal routes that can be advertised to all peers.
additional-paths select-best best-number
By default, a maximum of one Add-Path optimal route can be advertised to all peers.
399
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view.
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Configure the BGP Additional Paths capabilities. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } additional-paths { receive | send } *
By default, no BGP Additional Paths capabilities are configured.
4. Set the maximum number of Add-Path optimal routes that can be advertised to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise additional-paths best number
By default, a maximum of one Add-Path optimal route can be advertised to a peer or peer group.
5. Set the maximum number of Add-Path optimal routes that can be advertised to all peers.
additional-paths select-best best-number
By default, a maximum of one Add-Path optimal route can be advertised to all peers.
Configuring BGP optimal route selection delay
About this task
Typically BGP optimal route selection is triggered in real time by the events such as attribute change, configuration change, and route recursion. To avoid packet loss upon switchover between redundant links, you can perform this task to delay optimal route selection.
As shown in
Figure 88 , BGP runs on all devices in the network. Device A and Device D uses the
primary path for communication. When the primary path fails, Device A and Device D switch to the backup path for communication and then back to the primary path after the primary path recovers. In such case, traffic loss might occur if Device A forwards packets through Device B before Device B completes route convergence. You can configure optimal route selection delay on Device A to resolve the problem.
400
Figure 88 Network diagram
Device B
Device A Device D
Device C
Primary path
Backup path
Restrictions and guidelines
Follow these restrictions and guidelines when you configure this feature:
•
The optimal route selection delay setting applies only when multiple effective routes with the same prefix exist after a route change occurs.
•
For routes being delayed for optimal route selection, modifying the optimal route selection delay timer has the following effects:
If you modify the delay timer to a non-zero value, the routes are not affected, and they still use the original delay timer.
If you execute the undo form of the route-select delay command or modify the delay timer to 0, the device performs optimal route selection immediately.
•
If you execute the command multiple times for an address family, the most recent configuration takes effect.
•
The optimal route selection delay configuration does not apply to the following conditions:
A route change is caused by execution of a command or by route withdrawal.
After a route change occurs, only one route exists for a specific destination network.
An active/standby process switchover occurs.
A route change occurs among equal-cost routes.
Only the optimal and suboptimal routes exist when FRR is configured.
Optimal route selection is triggered by a redistributed route.
The next hop of the optimal route changes and a route with the same prefix is waiting for the delay timer to expire.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
401
address-family ipv4 [ unicast ]
3. Set the optimal route selection delay timer.
route-select delay delay-value
By default, the optimal route selection delay timer is 0 seconds, which means optimal route selection is not delayed.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view. bgp as-number [ instance instance-name ]
address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Set the optimal route selection delay timer.
route-select delay delay-value
By default, the optimal route selection delay timer is 0 seconds, which means optimal route selection is not delayed.
Setting the delay time for responding to recursive next hop changes
About this task
Next hop changes include the following types:
•
Critical next hop changes —Changes that cause route unreachability and service interruption.
For example, a BGP route cannot find a recursive next hop (a physical interface or tunnel interface) because of network failures.
•
Noncritical next hop changes —A recursive or related route changes but the change does not cause route unreachability or service interruption. For example, the recursive next hop (a physical interface or tunnel interface) of a BGP route changes but traffic forwarding is not affected.
When recursive or related routes change frequently, configure this feature to reduce unnecessary path selection and update messages and prevent traffic loss.
Restrictions and guidelines
To avoid traffic loss, do not configure this feature if only one route is available to a specific destination.
Set an appropriate delay time based on your network condition. A short delay time cannot reduce unnecessary path selection or update messages, and a long delay time might cause traffic loss.
Procedure (IPv4 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
402
Enter BGP IPv4 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Set the delay time for responding to recursive next hop changes. nexthop recursive-lookup [ non-critical-event ] delay [ delay-value ]
By default, BGP responds to recursive next hop changes immediately.
Procedure (IPv6 unicast address family)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view. bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Set the delay time for responding to recursive next hop changes. nexthop recursive-lookup [ non-critical-event ] delay [ delay-value ]
By default, BGP responds to recursive next hop changes immediately.
Configuring peer flap dampening
About this task
Perform this task to dampen a BGP peer when the peer state frequently changes between up and down. BGP increases the idle time of the peer each time the peer comes up until the maximum idle time is reached. To exit the dampened state, the peer must remain in Established state for a time period longer than the minimum established time. After the peer exits the dampened state, BGP resets the idle time of the peer when the peer comes up again.
Restrictions and guidelines
Set a maximum idle time and a minimum established time based on your network condition.
Procedure
1. Enter system view.
system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
403
ip vpn-instance vpn-instance-name
3. Configure flap dampening for a peer or peer group. peer { group-name | ipv4-address | ipv6-address } flap-dampen
[ max-idle-time max-time | min-established-time min-time ] *
By default, flap dampening is disabled for all peers and peer groups.
Protecting an EBGP peer when memory usage reaches level 2 threshold
About this task
Memory usage includes the following threshold levels: normal, level 1, level 2, and level 3. When the level 2 threshold is reached, BGP periodically tears down an EBGP session to release memory resources until the memory usage falls below the level 2 threshold. You can configure this feature to avoid tearing down the EBGP session to an EBGP peer when the memory usage reaches the level 2 threshold.
For more information about memory usage thresholds, see device management configuration in
Fundamentals Configuration Guide .
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to protect an EBGP peer or peer group when the memory usage reaches level
2 threshold. peer { group-name | ipv4-address [ mask-length ] } low-memory-exempt
By default, BGP periodically tears down an EBGP session to release memory resources when level 2 threshold is reached.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure BGP to protect an EBGP peer or peer group when the memory usage reaches level
2 threshold. peer { group-name | ipv6-address [ prefix-length ] } low-memory-exempt
By default, BGP tears down an EBGP session to release memory resources periodically when level 2 threshold is reached.
404
Setting a DSCP value for outgoing BGP packets
About this task
The DSCP value of an IP packet specifies the priority level of the packet and affects the transmission priority of the packet.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Set a DSCP value for outgoing BGP packets. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } dscp dscp-value
By default, the DSCP value for outgoing BGP packets is 48.
Disabling route recursion policy control for routes received from a peer or peer group
About this task
If you configure routing policy-based recursive lookup for BGP routes, this route recursion policy applies to BGP routes learned from all peers. This task allows you to disable route recursion policy control for routes learned from certain peers, for example, direct EBGP peers.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Disable route recursion policy control for routes received from the specified peer or peer group. peer { group-name | ip-address [ mask-length ] | ipv6-address
[ prefix-length ] } nexthop-recursive-policy disable
By default, the route recursion policy applies to routes received from the peer or peer group.
405
Flushing the suboptimal BGP route to the RIB
About this task
This feature flushes the suboptimal BGP route to the RIB when the following conditions are met:
•
The optimal route is generated by the network command or is redistributed by the import-route command.
•
The suboptimal route is received from a BGP peer.
After the suboptimal route is flushed to the RIB on a network, BGP immediately switches traffic to the suboptimal route when the optimal route fails.
For example, the device has a static route to the subnet 1.1.1.0/24 that has a higher priority than a
BGP route. BGP redistributes the static route and receives a route to 1.1.1.0/24 from a peer. After the flush suboptimal-route command is executed, BGP flushes the received BGP route to the
RIB as the suboptimal route. When the static route fails, BGP immediately switches traffic to the suboptimal route if inter-protocol FRR is enabled. For more information about inter-protocol FRR,
see " Configuring basic IP routing ."
Procedure
1. Enter system view. system-view
2. Enter BGP view.
bgp as-number [ instance instance-name ]
3. Flush the suboptimal BGP route to the RIB. flush suboptimal-route
By default, BGP is disabled from flushing the suboptimal BGP route to the RIB, and only the optimal route is flushed to the RIB.
Specifying a label allocation mode
About this task
BGP supports the following label allocation modes:
•
Per-prefix —Allocates a label to each route prefix.
•
Per-next-hop —Allocates a label to each next hop. This mode is applicable when the number of labels required by the per-prefix mode exceeds the maximum number of labels supported by the device.
•
Per-VPN-instance —Allocates a label to each VPN instance. This mode is applicable when the number of labels required by the per-next-hop mode exceeds the maximum number of labels supported by the device.
Restrictions and guidelines
When you specify the per-prefix or per-next-hop label allocation mode, you can execute the vpn popgo command to specify the POPGO forwarding mode on an egress PE. The egress PE will pop the label for each packet and forward the packet out of the interface corresponding to the label.
When you specify the per-VPN instance label allocation mode, do not execute the vpn popgo command because it is mutually exclusive with the label-allocation-mode per-vrf command. The egress PE will pop the label for each packet and forward the packet through the FIB table.
406
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Specify a label allocation mode. label-allocation-mode { per-prefix | per-vrf }
By default, BGP allocates labels on a per-next-hop basis.
CAUTION:
A change to the label allocation mode enables BGP to re-advertise all routes, which will cause service interruption. Use this command with caution.
Disabling optimal route selection for labeled routes without tunnel information
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Disable optimal route selection for labeled routes without tunnel information. labeled-route ignore-no-tunnel
By default, labeled routes without tunnel information can participate in optimal route selection.
Disabling MPLS local IFNET tunnel establishment
About this task
An MPLS local IFNET tunnel is automatically established between MP-EBGP peers. Only directly connected MP-EBGP peers are able to forward traffic through this tunnel.
For two indirectly connected MP-EBGP peers, traffic between them is interrupted upon failover to the
MPLS local IFNET tunnel. To avoid this issue, you can disable BGP from establishing MPLS local
IFNET tunnels to the specified EBGP peer or peer group.
Restrictions and guidelines
Disabling MPLS local IFNET tunnel establishment deletes the MPLS local IFNET tunnels already established to the specified EBGP peer or peer group.
Disabling BGP from establishing MPLS local IFNET tunnels to directly connected EBGP peers and peer groups will cause traffic loss. Make sure you fully understand the impact before performing the operation.
Procedure
1. Enter system view.
system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
407
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Disable MPLS local IFNET tunnel establishment to the specified EBGP peer or peer group. peer { group name | ipv4-address [ mask-length ] } mpls-local-ifnet disable
By default, MPLS local IFNET tunnel establishment is enabled. Two MP-EBGP peers automatically establish an MPLS local IFNET tunnel after they exchange labeled routes and
VPNv4 routes.
Resetting BGP sessions
About this task
A reset operation terminates and re-establishes BGP sessions in order to validate configuration changes and update routing information.
Restrictions and guidelines
A reset operation tears down BGP sessions for a short period of time.
Procedure
Perform reset tasks in user view.
•
Resets BGP sessions for the IPv4 unicast address family. reset bgp [ instance instance-name ] { as-number | ipv4-address
[ mask-length ] | all | external | group group-name | internal } ipv4
[ unicast ] [ vpn-instance vpn-instance-name ] reset bgp [ instance instance-name ] ipv6-address [ prefix-length ] ipv4 [ unicast ] [ vpn-instance vpn-instance-name ]
•
Resets BGP sessions for the IPv6 unicast address family. reset bgp [ instance instance-name ] { as-number | ipv6-address
[ prefix-length ] | all | external | group group-name | internal } ipv6
[ unicast ] [ vpn-instance vpn-instance-name ] reset bgp ipv4-address [ mask-length ] ipv6 [ unicast ] [ vpn-instance vpn-instance-name ]
•
Resets all BGP sessions. reset bgp [ instance instance-name ] all
For more information about the reset commands, see Basic BGP commands in Layer 3—IP Routing
Command Reference .
BGP network tuning and optimization configuration examples
Example: Configuring BGP load balancing
Network configuration
As shown in Figure 89 , run EBGP between Device A and Device B, and between Device A and
Device C. Run IBGP between Device B and Device C.
408
Configure load balancing over the two EBGP links on Device A.
Figure 89 Network diagram
AS 65009 Loop0
2.2.2.2/32
HGE1/0/1
8.1.1.1/24
AS 65008
Loop0
1.1.1.1/32
HGE1/0/2
3.1.1.2/24
HGE1/0/3
Device A
3.1.2.2/24
EBGP
EBGP
HGE1/0/2
3.1.1.1/24
Device B
HGE1/0/1
9.1.1.1/24
IBGP
HGE1/0/1
9.1.1.2/24
HGE1/0/2
3.1.2.1/24
Loop0
3.3.3.3/32
Device C
Procedure
Intranet
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure BGP connections:
On Device A, establish EBGP connections with Device B and Device C. Configure BGP to advertise network 8.1.1.0/24 to Device B and Device C. This allows Device B and Device C can access the internal network connected to Device A.
On Device B, establish an EBGP connection with Device A and an IBGP connection with
Device C. Configure BGP to advertise network 9.1.1.0/24 to Device A, so that Device A can access the intranet through Device B. Configure a static route to interface loopback 0 on
Device C (or use a routing protocol like OSPF) to establish the IBGP connection.
On Device C, establish an EBGP connection with Device A and an IBGP connection with
Device B. Configure BGP to advertise network 9.1.1.0/24 to Device A, so that Device A can access the intranet through Device C. Configure a static route to interface loopback 0 on
Device B (or use another protocol like OSPF) to establish the IBGP connection.
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 65008
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 3.1.1.1 as-number 65009
[DeviceA-bgp-default] peer 3.1.2.1 as-number 65009
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 3.1.1.1 enable
[DeviceA-bgp-default-ipv4] peer 3.1.2.1 enable
[DeviceA-bgp-default-ipv4] network 8.1.1.0 24
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device B.
409
<DeviceB> system-view
[DeviceB] bgp 65009
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 3.1.1.2 as-number 65008
[DeviceB-bgp-default] peer 3.3.3.3 as-number 65009
[DeviceB-bgp-default] peer 3.3.3.3 connect-interface loopback 0
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 3.1.1.2 enable
[DeviceB-bgp-default-ipv4] peer 3.3.3.3 enable
[DeviceB-bgp-default-ipv4] network 9.1.1.0 24
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
[DeviceB] ip route-static 3.3.3.3 32 9.1.1.2
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 65009
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 3.1.2.2 as-number 65008
[DeviceC-bgp-default] peer 2.2.2.2 as-number 65009
[DeviceC-bgp-default] peer 2.2.2.2 connect-interface loopback 0
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 3.1.2.2 enable
[DeviceC-bgp-default-ipv4] peer 2.2.2.2 enable
[DeviceC-bgp-default-ipv4] network 9.1.1.0 24
[DeviceC-bgp-default-ipv4] quit
[DeviceC-bgp-default] quit
[DeviceC] ip route-static 2.2.2.2 32 9.1.1.1
# Display the BGP routing table on Device A.
[ DeviceA ] display bgp routing-table ipv4
Total number of routes: 3
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* > 8.1.1.0/24 8.1.1.1 0 32768 i
* >e 9.1.1.0/24 3.1.1.1 0 0 65009i
* e 3.1.2.1 0 0 65009i
The output shows two valid routes to destination 9.1.1.0/24. The route with next hop 3.1.1.1 is marked with a greater-than sign (>), indicating that it is the optimal route. The route with next hop 3.1.2.1 is marked with an asterisk ( * ), indicating that it is a valid route, but not the optimal route.
By using the display ip routing-table command, you can find there is only one route to 9.1.1.0/24 with next hop 3.1.1.1 and output interface HundredGigE 1/0/2.
410
3. On Device A, configure the maximum number of ECMP routes destined for AS 65009 as 2 to improve link usage.
[DeviceA] bgp 65008
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] balance 2
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
Verifying the configuration
# Display the BGP routing table on Device A.
[ DeviceA ] display bgp routing-table ipv4
Total number of routes: 3
BGP local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* > 8.1.1.0/24 8.1.1.1 0 32768 i
* >e 9.1.1.0/24 3.1.1.1 0 0 65009i
* >e 3.1.2.1 0 0 65009i
•
The output shows that there are two valid routes to the destination 9.1.1.0/24, and both of them are the optimal routes.
•
By using the display ip routing-table command, you can find there are two routes to
9.1.1.0/24. One has next hop 3.1.1.1 and output interface HundredGigE 1/0/2, and the other has next hop 3.1.2.1 and output interface HundredGigE 1/0/3.
Example: Configuring the BGP Additional Paths feature
Network configuration
As shown in
Figure 90 , all devices run BGP. EBGP runs between Device A and Device B, and
between Device A and Device C. IBGP runs between Device B and Device D, between Device C and
Device D, and between Device D and Device E. Device D is a route reflector and Device E is its client.
Configure the BGP Additional Paths feature to enable Device E to learn routes with the same prefix and different next hops from Device B and Device C.
411
Figure 90 Network diagram
AS 20
HGE1/0/1 HGE1/0/2
AS 10
Device B
HGE1/0/1
HGE1/0/1
HGE1/0/2
Device D
HGE1/0/3
HGE1/0/1
Device E HGE1/0/2
Device A
HGE1/0/1
Device C
HGE1/0/2
Table 23 Interface and IP address assignment
Device
Device A
Device B
Device C
Procedure
Interface IP address
HGE1/0/1 10.1.1.1/24
HGE1/0/2 20.1.1.1/24
HGE1/0/1 10.1.1.2/24
HGE1/0/2 30.1.1.2/24
HGE1/0/1 20.1.1.2/24
HGE1/0/2 40.1.1.2/24
Device
Device D
Device E
Interface IP address
HGE1/0/1 30.1.1.1/24
HGE1/0/2 40.1.1.1/24
HGE1/0/3 50.1.1.1/24
HGE1/0/1 50.1.1.2/24
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure BGP connections:
# Configure Device A.
<DeviceA> system-view
[ DeviceA ] bgp 10
[ DeviceA-bgp-default ] peer 10.1.1.2 as-number 20
[ DeviceA-bgp-default ] peer 20.1.1.2 as-number 20
[ DeviceA-bgp-default ] address-family ipv4 unicast
[ DeviceA-bgp-default-ipv4 ] peer 10.1.1.2 enable
[ DeviceA-bgp-default-ipv4 ] peer 20.1.1.2 enable
# Configure Device B.
<DeviceB> system-view
[ DeviceB ] bgp 20
[ DeviceB-bgp-default ] peer 10.1.1.1 as-number 10
[ DeviceB-bgp-default ] peer 30.1.1.1 as-number 20
[ DeviceB-bgp-default ] address-family ipv4 unicast
[ DeviceB-bgp-default-ipv4 ] peer 10.1.1.1 enable
[ DeviceB-bgp-default-ipv4 ] peer 30.1.1.1 enable
# Configure Device C.
412
<DeviceC> system-view
[ DeviceC ] bgp 20
[ DeviceC-bgp-default ] peer 20.1.1.1 as-number 10
[ DeviceC-bgp-default ] peer 40.1.1.1 as-number 20
[ DeviceC-bgp-default ] address-family ipv4 unicast
[ DeviceC-bgp-default-ipv4 ] peer 10.1.1.1 enable
[ DeviceC-bgp-default-ipv4 ] peer 30.1.1.1 enable
# Configure Device D.
<DeviceD> system-view
[ DeviceD ] bgp 20
[ DeviceD-bgp-default ] peer 30.1.1.2 as-number 20
[ DeviceD-bgp-default ] peer 40.1.1.2 as-number 20
[ DeviceD-bgp-default ] peer 50.1.1.2 as-number 20
[ DeviceD-bgp-default ] address-family ipv4 unicast
[ DeviceD-bgp-default-ipv4 ] peer 30.1.1.2 enable
[ DeviceD-bgp-default-ipv4 ] peer 40.1.1.2 enable
[ DeviceD-bgp-default-ipv4 ] peer 50.1.1.2 enable
# Configure Device E.
<DeviceE> system-view
[ DeviceE ] bgp 20
[ DeviceE-bgp-default ] peer 50.1.1.1 as-number 20
[ DeviceE-bgp-default ] address-family ipv4 unicast
[ DeviceE-bgp-default-ipv4 ] peer 50.1.1.1 enable
3. Configure Device A to advertise network 10.1.1.0/24.
[ DeviceA-bgp-default-ipv4 ] network 10.1.1.0 24
4. Set the local Device as the next hop for routes sent to a peer:
# Configure Device B.
[ DeviceB-bgp-default-ipv4 ] peer 30.1.1.1 next-hop-local
# Configure Device C.
[ DeviceC-bgp-default-ipv4 ] peer 40.1.1.1 next-hop-local
5. Configure Device D as a route reflector.
[ DeviceD-bgp-default-ipv4 ] peer 50.1.1.2 reflect-client
6. Configure the Additional Paths feature:
# Enable the additional path sending capability on Device D.
[ DeviceD-bgp-default-ipv4 ] peer 50.1.1.2 additional-paths send
# Set the maximum number to 2 for Add-Path optimal routes that can be advertised.
[ DeviceD-bgp-default-ipv4 ] additional-paths select-best 2
# Set the maximum number to 2 for Add-Path optimal routes that can be advertised to peer
50.1.1.2.
[ DeviceD-bgp-default-ipv4 ] peer 50.1.1.2 advertise additional-paths best 2
# Enable the additional path receiving capability on Device E.
[ DeviceE-bgp-default-ipv4 ] peer 50.1.1.1 additional-paths receive
Verifying the configuration
# Display BGP routing information on Device E.
[ DeviceE ] display bgp routing-table ipv4
Total number of routes: 2
413
BGP local router ID is 50.1.1.2
Status codes: * - valid, > - best, d - dampened, h - history
s - suppressed, S - stale, i - internal, e - external
a - additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
i 10.1.1.0/24 30.1.1.2 0 100 0 10i
i 40.1.1.2 0 100 0 10i
The output shows that Router D has learned two routes with the same prefix and different next hops.
414
Configuring BGP security features
BGP security feature configuration tasks at a glance
To configure BGP security features, perform the following tasks:
•
Enabling MD5 authentication for BGP peers
•
•
Enabling keychain authentication for BGP peers
•
Configuring IPsec for IPv6 BGP
•
Enabling MD5 authentication for BGP peers
About this task
MD5 authentication provides the following benefits:
•
Peer authentication ensures that only BGP peers that have the same password can establish
TCP connections.
•
Integrity check ensures that BGP packets exchanged between peers are intact.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable MD5 authentication for a BGP peer group or peer. peer { group-name | ipv4-address [ mask-length ] } password { cipher | simple } password
By default, MD5 authentication is disabled.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
415
3. Enable MD5 authentication for a BGP peer group or peer. peer { group-name | ipv6-address [ prefix-length ] } password { cipher
| simple } password
By default, MD5 authentication is disabled.
Configuring GTSM for BGP
About this task
The Generalized TTL Security Mechanism (GTSM) protects a BGP session by comparing the TTL value in the IP header of incoming BGP packets against a valid TTL range. If the TTL value is within the valid TTL range, the packet is accepted. If not, the packet is discarded.
The valid TTL range is from 255 – the configured hop count + 1 to 255.
When GTSM is configured, the BGP packets sent by the device have a TTL of 255.
GTSM provides best protection for directly connected EBGP sessions, but not for multihop EBGP or
IBGP sessions because the TTL of packets might be modified by intermediate devices.
Restrictions and guidelines
When GTSM is configured, the local device can establish an EBGP session to the peer after both devices pass GTSM check, regardless of whether the maximum number of hops is reached.
To use GTSM, you must configure GTSM on both the local and peer devices. You can specify different hop-count values for them.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure GTSM for the specified BGP peer or peer group. peer { group-name | ipv4-address [ mask-length ] } ttl-security hops hop-count
By default, GTSM is disabled.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Configure GTSM for the specified BGP peer or peer group.
416
peer { group-name | ipv6-address [ prefix-length ] } ttl-security hops hop-count
By default, GTSM is disabled.
Enabling keychain authentication for BGP peers
About this task
Keychain authentication enhances the security of BGP in the following ways:
•
BGP peers can establish TCP connections only when they use the same key for keychain authentication.
•
The keys used by the BGP peers at the same time must have the same ID.
•
The keys with the same ID must use the same authentication algorithm and key string.
For more information about keychains, see Security Configuration Guide .
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable keychain authentication for a BGP peer or peer group. peer { group-name | ip-address [ mask-length ] } keychain keychain-name
By default, keychain authentication is disabled.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable keychain authentication for a BGP peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } keychain keychain-name
By default, keychain authentication is disabled.
417
Configuring IPsec for IPv6 BGP
About this task
Perform this task to configure IPsec for IPv6 BGP. IPsec can protect IPv6 BGP packets from data eavesdropping, tampering, and attacks caused by forged IPv6 BGP packets.
When two IPv6 BGP peers are configured with IPsec (for example, Device A and Device B), Device
A encapsulates an IPv6 BGP packet with IPsec before sending it to Device B. If Device B successfully receives and de-encapsulates the packet, it establishes an IPv6 BGP peer relationship with Device A and learns IPv6 BGP routes from Device A. If Device B receives but fails to de-encapsulate the packet, or receives a packet not protected by IPsec, it discards the packet.
Procedure
1. Enter system view. system-view
2. Configure an IPsec transform set and a manual IPsec profile.
For more information about this task, see Security Configuration Guide .
3. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
4. Apply the IPsec profile to an IPv6 BGP peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } ipsec-profile profile-name
By default, no IPsec profile is configured for an IPv6 BGP peer or peer group.
This command supports only IPsec profiles in manual mode.
Configuring BGP RPKI
About BGP RPKI
The AS_PATH attribute identifies the ASs through which a route has passed, and the AS that originated the route is the origin AS of the route. If the origin AS number of a route is incorrect, traffic transmission failure or even network collapse might occur.
To avoid this problem, you can configure the BGP Resource Public Key Infrastructure (RPKI) feature.
It enables BGP to validate the origin AS of a route and determine whether to use and advertise the route based on the validation state.
Configuring RPKI connection parameters
About this task
A router establishes a TCP connection with an RPKI server to obtain the Route Origin Authorization
(ROA) information used for RPKI validation. The router checks the connection to the RPKI server at the specified interval. If the router does not receive a response from the RPKI server within the specified time period, it tears down the connection to the RPKI server.
418
When the connection between a router and an RPKI server goes down (except when the shutdown command is executed), the router takes the following actions:
•
Attempts to reconnect to the server.
•
Places the ROA information obtained from the server in aging state, and starts the aging timer for the ROA information.
If the router reconnects to the server before the aging timer expires, it releases the ROA information from the aging state. If the router fails to reconnect to the server when the aging timer expires, it deletes the ROA information obtained from the server.
Restrictions and guidelines
Follow these restrictions and guidelines when you configure RPKI connection parameters:
•
As a best practice, set an ROA information aging time longer than the time to wait for the response from the RPKI server.
•
To tear down the connection to an RPKI server, execute the undo port command in RPKI server view.
•
If you execute the undo rpki command, all configurations in RPKI view are removed.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP RPKI view. rpki
4. Specify an RPKI server by its IP address and enter RPKI server view. server [ vpn-instance vpn-instance-name ] tcp { ipv4-address | ipv6-address }
By default, no RPKI server is specified.
5. Specify the port number of the RPKI server. port port-number
By default, the port number of the RPKI server is not specified.
To enable a router to establish a TCP connection with the RPKI server, you must configure the port number of the RPKI server on the router.
6. (Optional.) Specify the MD5 authentication password. passwords { cipher | simple } string
By default, the RPKI server does not perform MD5 authentication.
The MD5 authentication password must be the same as the authentication password configured on the RPKI server.
MD5 authentication ensures the validity of the RPKI server and the security of BGP RPKI packets.
7. (Optional.) Set the RPKI connection check interval.
refresh-time refresh-time
By default, the RPKI connection check interval is 600 seconds.
8. (Optional.) Set the time to wait for the response from the RPKI server.
response-time response-time
By default, the time to wait for the response from the RPKI server is 30 seconds.
9. (Optional.) Set the aging time for the ROA information.
419
purge-time purge-time
By default, the aging time for the ROA information is 60 seconds.
Enabling BGP RPKI validation
About this task
After you configure this feature, BGP validates the prefix and origin AS number of a received route and places the route to one of the following validation states:
•
Not-found —No ROA matches the prefix.
•
Valid —One or multiple ROAs match both the prefix and origin AS number.
•
Invalid —One or multiple ROAs match the prefix, but none of the ROAs matches the origin AS number.
Restrictions and guidelines
If you configure this feature, BGP uses the local RPKI validation states. If you do not configure this feature, BGP uses the validation states in the received BGP routes.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP RPKI view. rpki
4. Enable BGP RPKI validation. check-origin-validation
By default, BGP RPKI validation is disabled.
Applying the BGP RPKI validation state to optimal route selection
About this task
If multiple routes to the same destination are available, BGP first discards routes with unreachable next hops, and then selects the optimal route according to the following rules:
•
Routes with a BGP RPKI validation state of Valid takes precedence over routes with a validation state of Not-found or Invalid .
•
Routes with a BGP RPKI validation state of Not-found takes precedence over routes with a validation state of Invalid .
•
Routes without a BGP RPKI validation state have the same priority as routes with a BGP RPKI validation state of Not-found .
•
For routes that have the same BGP RPKI validation state, BGP selects the optimal route according to the BGP path selection rules. For more information about BGP path selection rules,
You can configure a routing policy to filter routes based on the BGP RPKI validation state. For more
information about routing policies, see " Configuring routing policies ."
Procedure (IPv4 unicast)
1. Enter system view.
420
system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view.
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Apply the BGP RPKI validation state to optimal route selection. bestroute origin-as-validation [ allow-invalid ]
By default, BGP ignores the BGP RPKI validation state during optimal route selection.
To allow routes with a validation state of Invalid to participate in optimal route selection, you must specify the allow-invalid keyword.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view.
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Apply the BGP RPKI validation state to optimal route selection. bestroute origin-as-validation [ allow-invalid ]
By default, BGP ignores the BGP RPKI validation state during optimal route selection.
To allow routes with a validation state of Invalid to participate in optimal route selection, you must specify the allow-invalid keyword.
Advertising BGP RPKI validation state to a peer or peer group
Restrictions and guidelines
BGP advertises the BGP RPKI validation state to a peer or peer group through the extended community attribute. To enable this feature, you must first enable BGP to advertise the extended community attribute to the peer or peer group and make sure RPKI settings are correct.
In the current software version, BGP can advertise the BGP RPKI validation state only to IBGP peers and peer groups.
Procedure (IPv4 unicast)
1. Enter system view. system-view
2. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
421
Enter BGP IPv4 unicast address family view.
bgp as-number [ instance instance-name ] address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
3. Advertise the extended community attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-ext-community
By default, BGP does not advertise the extended community attribute.
4. Advertise the BGP RPKI validation state to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise origin-as-validation
By default, BGP does not advertise the BGP RPKI validation state.
Procedure (IPv6 unicast)
1. Enter system view. system-view
2. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
Enter BGP IPv6 unicast address family view.
bgp as-number [ instance instance-name ] address-family ipv6 [ unicast ]
Enter BGP-VPN IPv6 unicast address family view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name address-family ipv6 [ unicast ]
3. Advertise the extended community attribute to a peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise-ext-community
By default, BGP does not advertise the extended community attribute.
4. Advertise the BGP RPKI validation state to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } advertise origin-as-validation
By default, BGP does not advertise the BGP RPKI validation state.
Verifying and maintaining BGP security features
Verifying and maintaining BGP RPKI
Verifying RPKI server configuration and running status (IPv4 unicast address family)
Perform display tasks in any view.
•
Display information about connections to RPKI servers. display bgp [ instance instance-name ] rpki server [ [ vpn-instance vpn-instance-name ] ipv4-address ]
422
•
Display the ROA information obtained from RPKI servers. display bgp [ instance instance-name ] rpki table ipv4 [ ipv4-address min min-length max max-length ]
Verifying RPKI server configuration and running status (IPv6 unicast address family)
Perform display tasks in any view.
•
Display information about connections to RPKI servers. display bgp [ instance instance-name ] rpki server [ [ vpn-instance vpn-instance-name ] ipv6-address ]
•
Display the ROA information obtained from RPKI servers. display bgp [ instance instance-name ] rpki table ipv6 [ ipv6-address min min-length max max-length
Resetting BGP RPKI sessions
To reset BGP RPKI sessions, execute the following command in user view: reset bgp [ instance instance-name ] rpki server [ vpn-instance vpn-instance-name ] tcp { ipv4 address | ipv6 address }
CAUTION:
After you execute this command, the device will delete and re-establish the specified BGP RPKI session and cause temporary session interruption.
Verifying and maintaining BGP GTSM
To display BGP GTSM discarded packet statistics, execute the following command in any view: display ttl-security statistics [ slot slot-number ]
To clear BGP GTSM discarded packet statistics, execute the following command in user view: reset ttl-security statistics [ slot slot-number ]
IPv4 BGP security feature configuration examples
Example: Configuring BGP RPKI
Network configuration
As shown in
Figure 91 , all devices run BGP. Establish a TCP connection between Device A and the
RPKI server, and establish an IBGP connection between Device A and Device B.
Configure Device A to advertise the BGP RPKI validation state to Device B, and configure a routing policy to filter routes based on the validation state for Device B.
423
Figure 91 Network diagram
RPKI server
1.1.1.2/24
1.1.1.1/24
HGE1/0/1
1.2.3.1/24
HGE1/0/1
1.2.3.2/24
AS 100 Device A Device B
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces and establish an IBGP connection between Device A and
Device B. (Details not shown.)
2. Configure Device A to establish a TCP connection to the RPKI server.
<DeviceA> system-view
[ DeviceA ] bgp 100
[ DeviceA-bgp-default ] rpki
[ DeviceA-bgp-default-rpki ] server tcp 1.1.1.2
[ DeviceA-bgp-default-rpki-server ] port 1234
[ DeviceA-bgp-default-rpki-server ] quit
3. Enable BGP RPKI validation on Device A.
[ DeviceA-bgp-default-rpki ] check-origin-validation
[ DeviceA-bgp-default-rpki ] quit
4. Apply the BGP RPKI validation state to optimal route selection.
[ DeviceA-bgp-default ] address-family ipv4
[ DeviceA-bgp-default-ipv4 ] bestroute origin-as-validation
5. Configure Device A to advertise the BGP RPKI validation state to peer 1.2.3.2.
[ DeviceA-bgp-default-ipv4 ] peer 1.2.3.2 advertise-ext-community
[ DeviceA-bgp-default-ipv4 ] peer 1.2.3.2 advertise origin-as-validation
[ DeviceA-bgp-default-ipv4 ] quit
[ DeviceA-bgp-default ] quit
6. Configure Device B to permit routes with a BGP RPKI validation state of Valid .
# Configure a routing policy.
<DeviceB> system-view
[ DeviceB ] route-policy rpki_policy permit node 0
[ DeviceB-route-policy-rpki_policy-0 ] if-match rpki valid
[ DeviceB-route-policy-rpki_policy-0 ] quit
424
# Apply the routing policy.
[ DeviceB ] bgp 100
[ DeviceB-bgp-default ] address-family ipv4
[ DeviceB-bgp-default-ipv4 ] peer 1.2.3.1 route-policy rpki_policy import
Verifying the configuration
# Display information about the connection between Device A and the RPKI server.
[ DeviceA ] display bgp rpki server
Server VPN-index Port State Time ROAs(IPv4/IPv6)
1.1.1.2 0 1234 Establish 00:04:43 5/4
The output shows that Device A has established a TCP connection to the RPKI server.
# Display the ROA information on Device A.
[ DeviceA ] display bgp rpki table ipv4
Total number of entries: 5
Status codes: S - stale, U - used
Network Mask-range Origin-AS Server Status
1.2.3.4 8-24 100 1.1.1.2 U
2.2.3.6 8-32 100 1.1.1.2 U
2.2.3.6 10-24 4294967295 1.1.1.2 U
2.2.3.9 20-24 4294967295 1.1.1.2 U
3.2.3.5 8-26 200 1.1.1.2 U
The output shows that Device A has obtained the ROA information from the RPKI server.
# Display the BGP RPKI validation state on Device A.
[ DeviceA ] display bgp routing-table ipv4 1.2.3.0
BGP local router ID: 2.2.2.2
Local AS number: 100
Paths: 1 available, 1 best
BGP routing table information of 1.2.3.0/24:
Imported route.
Original nexthop: 0.0.0.0
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
Org-validation : Valid
AS-path : (null)
Origin : incomplete
Attribute value : MED 0, pref-val 32768
State : valid, local, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
425
The route to 1.2.3.0 matches the ROA with a prefix of 1.2.3.4, a mask length range of 8 to 24, and an origin AS number of 100. Therefore, the BGP RPKI validation state of the route to 1.2.3.0 is Valid .
# On Device B, display detailed information about the BGP IPv4 unicast route to 1.2.3.0.
[ DeviceB ] display bgp routing-table ipv4 1.2.3.0
RR-client route.
From : 1.2.3.1 (192.168.56.22)
Rely nexthop : 1.2.3.1
Original nexthop: 1.2.3.1
OutLabel : NULL
Ext-Community : <Origin Valid State: Valid >
RxPathID : 0x0
TxPathID : 0x0
Org-validation : Valid
AS-path : (null)
Origin : incomplete
Attribute value : MED 0, localpref 100, pref-val 0
State : valid, internal, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
The output displays information about the BGP IPv4 unicast route to 1.2.3.0 because Device B permits routes with a BGP RPKI validation state of Valid .
IPv6 BGP security feature configuration examples
Example: Configuring BGP RPKI
Network configuration
As shown in
Figure 92 , all devices run IPv6 BGP. Establish a TCP connection between Device A and
the RPKI server, and establish an IBGP connection between Device A and Device B.
Configure Device A to advertise the BGP RPKI validation state to Device B, and configure a routing policy to filter routes based on the validation state for Device B.
Figure 92 Network diagram
RPKI server
1::2/64
1::1/64
AS 100 Device A
HGE1/0/1
2001::1/64
HGE1/0/1
2001::2/64
Device B
426
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for interfaces and establish an IBGP connection between Device A and Device B. (Details not shown.)
2. Configure Device A to establish a TCP connection to the RPKI server.
<DeviceA> system-view
[ DeviceA ] bgp 100
[ DeviceA-bgp-default ] rpki
[ DeviceA-bgp-default-rpki ] server tcp 1::2
[ DeviceA-bgp-default-rpki-server ] port 1234
[ DeviceA-bgp-default-rpki-server ] quit
3. Enable BGP RPKI validation on Device A.
[ DeviceA-bgp-default-rpki ] check-origin-validation
[ DeviceA-bgp-default-rpki ] quit
4. Apply the BGP RPKI validation state to optimal route selection.
[ DeviceA-bgp-default ] address-family ipv6
[ DeviceA-bgp-default-ipv6 ] bestroute origin-as-validation
5. Configure Device A to advertise the BGP RPKI validation state to peer 2001::2.
[ DeviceA-bgp-default-ipv6 ] peer 2001::2 advertise-ext-community
[ DeviceA-bgp-default-ipv6 ] peer 2001::2 advertise origin-as-validation
[ SwitchA-bgp-default-ipv6 ] quit
[ SwitchA-bgp-default ] quit
6. Configure Device B to permit routes with a BGP RPKI validation state of Valid :
# Configure a routing policy.
<DeviceB> system-view
[ DeviceB ] route-policy rpki_policy permit node 0
[ DeviceB-route-policy-rpki_policy-0 ] if-match rpki valid
# Apply the routing policy.
<DeviceB> system-view
[ DeviceB ] bgp 100
[ DeviceB-bgp-default ] address-family ipv6
[ DeviceB-bgp-default-ipv6 ] peer 2001::1 route-policy rpki_policy import
Verifying the configuration
# Display information about the connection between Device A and the RPKI server.
[ DeviceA ] display bgp rpki server
Server VPN-index Port State Time ROAs(IPv4/IPv6)
1::2 0 1234 Establish 00:04:43 5/5
The output shows that Device A has established a TCP connection to the RPKI server.
# Display the ROA information on Device A.
[ DeviceA ] display bgp rpki table ipv6
Total number of entries: 5
427
Status codes: S - stale, U - used
Network Mask-range Origin-AS Server Status
2001:4860:: 32-32 100 1::2 U
2404:6800:: 32-32 100 1::2 U
2607:F8B0:: 28-28 4294967295 1::2 U
2A03:ACE0:: 40-40 4294967295 1::2 U
2001::1 64-64 200 1::2 U
The output shows that Device A has obtained the ROA information from the RPKI server.
# Display the BGP RPKI validation state on Device A.
[ DeviceA ] display bgp routing-table ipv6 2001::1 64
BGP local router ID: 2.2.2.2
Local AS number: 100
Paths: 1 available, 1 best
BGP routing table information of 2001::1/64:
Imported route.
Original nexthop: 0.0.0.0
OutLabel : NULL
RxPathID : 0x0
TxPathID : 0x0
Org-validation : Valid
AS-path : (null)
Origin : incomplete
Attribute value : MED 0, pref-val 32768
State : valid, local, best
IP precedence : N/A
QoS local ID : N/A
The route to 2001::1 matches the ROA with a prefix of 2001::1, a prefix length range of 64 to 64, and an origin AS number of 200. Therefore, the BGP RPKI validation state of the route to 2001::1 is
Valid .
# On Device B, display detailed information about the BGP IPv6 unicast route to 2001::1.
[ DeviceB ] display bgp routing-table ipv6 2001::1 64
RR-client route.
From : 2001::1 64 (192.168.56.22)
Rely nexthop : 2001::1
Original nexthop: 2001::1
OutLabel : NULL
Ext-Community : <Origin Valid State: Valid >
RxPathID : 0x0
TxPathID : 0x0
Org-validation : Invalid
AS-path : (null)
Origin : incomplete
428
Attribute value : MED 0, localpref 100, pref-val 0
State : valid, internal, best
IP precedence : N/A
QoS local ID : N/A
Traffic index : N/A
The output displays information about the BGP IPv6 unicast route to 2001::1 because Device B permits routes with a BGP RPKI validation state of Valid .
429
Improving BGP network reliability
BGP network reliability improvement tasks at a glance
To improve the BGP network reliability, perform the following tasks:
•
•
•
•
Configuring BGP GR
About this task
Graceful Restart (GR) ensures forwarding continuous when a routing protocol restarts or an active/standby switchover occurs. Two routers are required to complete a GR process. The following are router roles in a GR process:
•
GR restarter —Performs GR upon a BGP restart or active/standby switchover.
•
GR helper —Helps the GR restarter to complete the GR process.
A device can act as a GR restarter and GR helper at the same time.
BGP GR works as follows:
1. The BGP GR restarter and helper exchange OPEN messages for GR capability negotiation. If both parties have the GR capability, they establish a GR-capable session. The GR restarter sends the GR timer set by the graceful-restart timer restart command to the GR helper in an OPEN message.
2. When an active/standby switchover occurs or BGP restarts, the GR restarter does not remove existing BGP routes from Routing Information Base (RIB) and Forwarding Information Base
(FIB). It still uses these routes for packet forwarding, and it starts the RIB purge timer (set by the graceful-restart timer purge-time command). The GR helper marks all routes learned from the GR restarter as stale instead of deleting them. It continues to use these routes for packet forwarding. During the GR process, packet forwarding is not interrupted.
3. After the active/standby switchover or BGP restart completes, the GR restarter re-establishes a
BGP session to the GR helper. If the BGP session fails to be established after both the GR timer and the extra timer to wait expire, the GR helper removes the stale routes. To set the extra timer to wait after the restart timer expires, execute the peer graceful-restart timer restart extra command.
4. If the BGP session is established, routing information is exchanged for the GR restarter to retrieve route entries and for the GR helper to recover stale routes.
5. Both the GR restarter and the GR helper start the End-Of-RIB marker waiting timer.
The End-Of-RIB marker waiting time is set by the graceful-restart timer wait-for-rib command. If routing information exchange is not completed within the time, the GR restarter does not receive new routes. The GR restarter updates the RIB with the BGP routes already learned, and removes the aged routes from the RIB. The GR helper removes the stale routes.
430
6. The GR restarter quits the GR process if routing information exchange is not completed within the RIB purge timer. It updates the RIB with the BGP routes already learned, and removes the aged routes.
When the TCP connection goes down, the hold timer expires, or the support for a new address family is added, BGP tears down and then re-establishes the peer sessions, which will cause traffic interruption. To avoid traffic interruption in these cases, enable BGP to reset peer sessions gracefully.
Restrictions and guidelines
Follow these guidelines when you configure BGP GR:
•
The End-Of-RIB indicates the end of route updates.
•
The maximum time to wait for the End-of-RIB marker configured on the local end is not advertised to the peer. It controls the time for the local end to receive updates from the peer. Set a large value for the maximum time to wait for the End-of-RIB marker when a large number of routes need to be exchanged.
•
As a best practice, perform the BGP GR configuration on both the GR restarter and GR helper.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable GR capability for BGP. graceful-restart
By default, GR capability is disabled for BGP.
4. Configure the GR timer. graceful-restart timer restart timer
The default setting is 150 seconds.
The time that a peer waits to re-establish a session must be less than the hold time.
5. (Optional.) Set the extra time to wait after the restart timer expires. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } graceful-restart timer restart extra { time | no-limit }
By default, the extra time to wait after the restart timer expires is 0 seconds.
6. Configure the maximum time to wait for the End-of-RIB marker. graceful-restart timer wait-for-rib timer
The default setting is 600 seconds.
7. Configure the RIB purge timer. graceful-restart timer purge-time timer
The default setting is 480 seconds.
8. (Optional.) Enable BGP to reset peer sessions gracefully. graceful-restart peer-reset [ all ]
By default, BGP does not reset peer sessions gracefully.
9. (Optional.) Configure the time that BGP must wait for other protocols to complete GR after BGP completes GR.
bgp update-delay wait-other-protocol seconds
By default, after BGP completes GR, it must wait a maximum of 300 seconds for other protocols to complete GR.
431
Configuring BGP NSR
About this task
To use BGP nonstop routing (NSR), the system must have a minimum of two MPUs.
NSR ensures nonstop services when BGP has redundant processes on multiple MPUs. In contrast to GR, NSR does not require a neighbor device to recover routing information.
BGP NSR backs up BGP state and data information from the active BGP process to the standby
BGP process. The standby BGP process takes over when any of the following events occurs:
•
The active BGP process restarts.
•
The MPU that runs the active BGP process fails.
Restrictions and guidelines
When both GR and NSR are configured for BGP, NSR has a higher priority than GR. The device will not act as the GR restarter. If the device acts as a GR helper, it cannot help the restarter to complete
GR.
To use BGP NSR in MPLS L3VPN, you must enable RIB NSR. For information about RIB NSR, see
" Configuring basic IP routing ."
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enable BGP NSR. non-stop-routing
By default, BGP NSR is disabled.
4. (Optional.) Configure the time that BGP must wait for other protocols to complete NSR after
BGP completes NSR.
bgp update-delay wait-other-protocol seconds
By default, after BGP completes NSR, it must wait a maximum of 300 seconds for other protocols to complete NSR.
Verifying and maintaining BGP NSR
To display BGP NSR status information, execute the following command in any view:
display bgp [ instance instance-name ] non-stop-routing status
Configuring BFD for BGP
About this task
BGP maintains neighbor relationships based on the keepalive timer and hold timer in seconds. It requires that the hold time must be at least three times the keepalive interval. This mechanism slows down link failure detection. Once a failure occurs on a high-speed link, a large quantity of packets will be dropped before routing convergence completes. BFD for BGP can solve this problem by fast detecting link failures to reduce convergence time.
Before you enable BFD for a BGP peer or peer group, you must establish a BGP session between the local router and the peer or peer group.
For more information about BFD, see High Availability Configuration Guide .
432
Restrictions and guidelines
If you have enabled GR, use BFD with caution because BFD might detect a failure before the system performs GR, which will result in GR failure. If you have enabled both BFD and GR for BGP, do not disable BFD during a GR process to avoid GR failure.
Procedure (IPv4 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BFD to detect the link to the specified BGP peer or peer group. peer { group-name | ipv4-address [ mask-length ] } bfd [ echo | multi-hop
| single-hop ]
By default, BFD is disabled.
Procedure (IPv6 peers)
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enable BFD to detect the link to the specified IPv6 BGP peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } bfd [ echo | multi-hop | single-hop ]
By default, BFD is disabled.
Configuring BGP FRR
About BGP FRR
When a link fails, the packets on the link are discarded, and a routing loop might occur until BGP completes routing convergence based on the new network topology.
You can enable BGP fast reroute (FRR) to resolve this issue.
433
Figure 93 Network diagram for BGP FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
After you configure FRR on Router B as shown in Figure 93 , BGP generates a backup next hop
Router C for the primary route. BGP uses ARP or BFD echo packet mode in an IPv4 network or ND in an IPv6 network to detect the connectivity to Router D. When the link to Router D fails, BGP directs packets to the backup next hop. At the same time, BGP calculates a new optimal route, and forwards packets over the optimal route.
You can use the following methods to configure BGP FRR:
•
Method 1 —Execute the pic command in BGP address family view. BGP calculates a backup next hop for each BGP route in the address family if there are two or more unequal-cost routes that reach the destination.
•
Method 2 —Execute the fast-reroute route-policy command to use a routing policy in which a backup next hop is specified by using the command apply [ ipv6 ] fast-reroute backup-nexthop . The backup next hop calculated by BGP must be the same as the specified backup next hop. Otherwise, BGP does not generate a backup next hop for the primary route. You can also configure if-match clauses in the routing policy to identify the routes protected by FRR.
If both methods are configured, Method 2 takes precedence over Method 1.
BGP supports FRR for IPv4 and IPv6 unicast routes.
Configuring BGP FRR by using a routing policy (IPv4 unicast address family)
1. Enter system view. system-view
2. Configure the source address of echo packets.
bfd echo-source-ip ipv4-address
By default, no source address is specified for echo packets.
This step is required when BFD echo packet mode is used to detect the connectivity to the next hop of the primary route.
Specify a source IP address that does not belong to any local network.
For more information about this command, see BFD commands in High Availability Command
Reference .
3. Create a routing policy and enter routing policy view.
route-policy route-policy-name permit node node-number
For more information about this command, see routing policy commands in Layer 3—IP
Routing Command Reference .
4. Set the backup next hop for FRR.
apply fast-reroute backup-nexthop ipv4-address
By default, no backup next hop is set.
434
For more information about this command, see routing policy commands in Layer 3—IP
Routing Command Reference .
5. Return to system view. quit
6. Enter BGP instance view. bgp as-number [ instance instance-name ]
7. (Optional.) Use echo mode BFD to detect the connectivity to the next hop of the primary route. primary-path-detect bfd { ctrl | echo }
By default, ARP is used to detect the connectivity to the next hop.
8. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Enter BGP IPv4 unicast address family view. address-family ipv4 [ unicast ]
Enter BGP-VPN IPv4 unicast address family view.
ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
9. Apply a routing policy to FRR for the address family.
fast-reroute route-policy route-policy-name
By default, no routing policy is applied.
The apply fast-reroute backup-nexthop command and apply ipv6 fast-reroute backup-nexthop command can take effect in the applied routing policy.
Other apply commands do not take effect.
Configuring BGP FRR by using a routing policy (IPv6 unicast address family)
1. Enter system view. system-view
2. Create a routing policy and enter routing policy view.
route-policy route-policy-name permit node node-number
For more information about this command, see routing policy commands in Layer 3—IP
Routing Command Reference .
3. Set the backup next hop for FRR.
apply ipv6 fast-reroute backup-nexthop ipv6-address
By default, no backup next hop is set.
For more information about this command, see routing policy commands in Layer 3—IP
Routing Command Reference .
4. Return to system view. quit
5. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view. bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view. bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
6. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
435
address-family ipv6 [ unicast ]
7. Apply a routing policy to FRR for the address family.
fast-reroute route-policy route-policy-name
By default, no routing policy is applied.
The apply fast-reroute backup-nexthop and apply ipv6 fast-reroute backup-nexthop commands can take effect in the applied routing policy. Other apply commands do not take effect.
Configuring BGP FRR through PIC (IPv4 unicast address family)
Restrictions and guidelines
This feature might result in routing loops. Use it with caution.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. address-family ipv4 [ unicast ]
4. Enable BGP FRR through PIC. pic
By default, BGP FRR is disabled.
Configuring BGP FRR through PIC (IPv6 unicast address family)
Restrictions and guidelines
This feature might result in routing loops. Use it with caution.
Procedure
1. Enter system view. system-view
2. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
3. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view.
436
address-family ipv6 [ unicast ]
4. Enable BGP FRR through PIC. pic
By default, BGP FRR is disabled.
IPv4 BGP network reliability improvement configuration examples
Example: Configuring BGP GR
Network configuration
As shown in Figure 94 , run EBGP between Device A and Device B, and run IBGP between Device B
and Device C.
Configure BGP GR so that the communication between Device A and Device C is not affected when an active/standby switchover occurs on Device B.
Figure 94 Network diagram
AS 65008 AS 65009
HGE1/0/1
8.1.1.1/8
Device A
( GR helper )
HGE1/0/2
200.1.1.2/24
HGE1/0/1
200.1.1.1/24
HGE1/0/2
9.1.1.1/24
Device B
( GR Restarter )
HGE1/0/1
9.1.1.2/24
Device C
( GR helper )
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure Device A:
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the EBGP connection.
<DeviceA> system-view
[DeviceA] bgp 65008
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 200.1.1.1 as-number 65009
# Enable GR capability for BGP.
[DeviceA-bgp-default] graceful-restart
# Inject network 8.0.0.0/8 to the IPv4 BGP routing table.
[DeviceA-bgp-default] address-family ipv4
[DeviceA-bgp-default-ipv4] network 8.0.0.0
# Enable Device A to exchange IPv4 unicast routing information with Device B.
[DeviceA-bgp-default-ipv4] peer 200.1.1.1 enable
2. Configure Device B:
437
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the EBGP connection.
<DeviceB> system-view
[DeviceB] bgp 65009
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 200.1.1.2 as-number 65008
# Configure the IBGP connection.
[DeviceB-bgp-default] peer 9.1.1.2 as-number 65009
# Enable GR capability for BGP.
[DeviceB-bgp-default] graceful-restart
# Inject networks 200.1.1.0/24 and 9.1.1.0/24 to the IPv4 BGP routing table.
[DeviceB-bgp-default] address-family ipv4
[DeviceB-bgp-default-ipv4] network 200.1.1.0 24
[DeviceB-bgp-default-ipv4] network 9.1.1.0 24
# Enable Device B to exchange IPv4 unicast routing information with Device A and Device C.
[DeviceB-bgp-default-ipv4] peer 200.1.1.2 enable
[DeviceB-bgp-default-ipv4] peer 9.1.1.2 enable
3. Configure Device C:
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the IBGP connection.
<DeviceC> system-view
[DeviceC] bgp 65009
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 9.1.1.1 as-number 65009
# Enable GR capability for BGP.
[DeviceC-bgp-default] graceful-restart
# Enable Device C to exchange IPv4 unicast routing information with Device B.
[DeviceC-bgp-default] address-family ipv4
[DeviceC-bgp-default-ipv4] peer 9.1.1.1 enable
Verifying the configuration
Ping Device C on Device A. Meanwhile, perform an active/standby switchover on Device B. The ping operation is successful during the whole switchover process. (Details not shown.)
Example: Configuring BFD for BGP
Network configuration
As shown in Figure 95 , configure OSPF as the IGP in AS 200.
•
Establish two IBGP connections between Device A and Device C. When both paths operate correctly, Device C uses the path Device A<—>Device B<—>Device C to communicate with network 1.1.1.0/24.
•
Configure BFD over the path. When the path fails, BFD can quickly detect the failure and notify it to BGP. Then, the path Device A<—>Device D<—>Device C takes effect immediately.
438
Figure 95 Network diagram
Device B
HGE1/0/2
3.0.1.1/24
HGE1/0/2
3.0.1.2/24
HGE1/0/1
3.0.2.1/24
HGE1/0/1
3.0.2.2/24
AS 100 1.1.1.0/24 AS 200 AS 300
Device A
HGE1/0/1
2.0.1.1/24
HGE1/0/1
2.0.1.2/24
HGE1/0/2
Device C
2.0.2.2/24
HGE1/0/2
2.0.2.1/24
Device D
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF so that Device A and Device C can reach each other. (Details not shown.)
3. Configure BGP on Device A:
# Establish two IBGP connections to Device C.
<DeviceA> system-view
[DeviceA] bgp 200
[DeviceA-bgp-default] peer 3.0.2.2 as-number 200
[DeviceA-bgp-default] peer 2.0.2.2 as-number 200
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 3.0.2.2 enable
[DeviceA-bgp-default-ipv4] peer 2.0.2.2 enable
[DeviceA-bgp-default-ipv4] quit
# Create IPv4 basic ACL 2000 to permit 1.1.1.0/24 to pass.
[DeviceA] acl basic 2000
[DeviceA-acl-ipv4-basic-2000] rule permit source 1.1.1.0 0.0.0.255
[DeviceA-acl-ipv4-basic-2000] quit
# Create two routing policies to set the MED for route 1.1.1.0/24. The policy apply_med_50 sets the MED to 50, and the policy apply_med_100 sets the MED to 100.
[DeviceA] route-policy apply_med_50 permit node 10
[DeviceA-route-policy-apply_med_50-10] if-match ip address acl 2000
[DeviceA-route-policy-apply_med_50-10] apply cost 50
[DeviceA-route-policy-apply_med_50-10] quit
[DeviceA] route-policy apply_med_100 permit node 10
[DeviceA-route-policy-apply_med_100-10] if-match ip address acl 2000
[DeviceA-route-policy-apply_med_100-10] apply cost 100
[DeviceA-route-policy-apply_med_100-10] quit
439
# Apply routing policy apply_med_50 to routes outgoing to peer 3.0.2.2, and apply routing policy apply_med_100 to routes outgoing to peer 2.0.2.2.
[DeviceA] bgp 200
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 3.0.2.2 route-policy apply_med_50 export
[DeviceA-bgp-default-ipv4] peer 2.0.2.2 route-policy apply_med_100 export
[DeviceA-bgp-default-ipv4] quit
# Enable BFD for peer 3.0.2.2.
[DeviceA-bgp-default] peer 3.0.2.2 bfd
[DeviceA-bgp-default] quit
4. Configure BGP on Device C:
# Establish two IBGP connections to Device A.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC-bgp-default] peer 3.0.1.1 as-number 200
[DeviceC-bgp-default] peer 2.0.1.1 as-number 200
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 3.0.1.1 enable
[DeviceC-bgp-default-ipv4] peer 2.0.1.1 enable
[DeviceC-bgp-default-ipv4] quit
# Enable BFD for peer 3.0.1.1.
[DeviceC-bgp-default] peer 3.0.1.1 bfd
[DeviceC-bgp-default] quit
[DeviceC] quit
Verifying the configuration
# Display detailed BFD session information on Device C.
<DeviceC> display bfd session verbose
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 Session Working in control packet mode:
Local Discr: 513 Remote Discr: 513
Source IP: 3.0.2.2 Destination IP: 3.0.1.1
Session State: Up Interface: N/A
Min Tx Inter: 500ms Act Tx Inter: 500ms
Min Rx Inter: 500ms Detect Inter: 2500ms
Rx Count: 135 Tx Count: 135
Connect Type: Indirect Running Up for: 00:00:58
Hold Time: 2457ms Auth mode: None
Detect Mode: Async Slot: 0
Protocol: BGP
Version:1
Diag Info: No Diagnostic
The output shows that a BFD session has been established between Device A and Device C.
# Display BGP peer information on Device C.
<DeviceC> display bgp peer ipv4
BGP local router ID: 3.3.3.3
440
Local AS number: 200
Total number of peers: 2 Peers in established state: 2
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
2.0.1.1 200 4 5 0 0 00:01:55 Established
3.0.1.1 200 4 5 0 0 00:01:52 Established
The output shows that Device C has established two BGP connections with Device A, and both connections are in Established state.
# Display route 1.1.1.0/24 on Device C.
<DeviceC> display ip routing-table 1.1.1.0 24 verbose
Summary count : 1
Destination: 1.1.1.0/24
Protocol: BGP Process ID: 0
SubProtID: 0x1 Age: 00h00m09s
Cost: 50 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x15000001 LastAs: 0
AttrID: 0x1 Neighbor: 3.0.1.1
Flags: 0x10060 OrigNextHop: 3.0.1.1
Label: NULL RealNextHop: 3.0.2.1
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device C communicates with network 1.1.1.0/24 through the path Device
C<—>Device B<—>Device A.
# Break down the link Device C<—>Device B<—>Device A and then display route 1.1.1.0/24 on
Device C.
<DeviceC> display ip routing-table 1.1.1.0 24 verbose
Summary count : 1
Destination: 1.1.1.0/24
Protocol: BGP Process ID: 0
SubProtID: 0x1 Age: 00h03m08s
441
Cost: 100 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x15000000 LastAs: 0
AttrID: 0x0 Neighbor: 2.0.1.1
Flags: 0x10060 OrigNextHop: 2.0.1.1
Label: NULL RealNextHop: 2.0.2.1
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device C communicates with network 1.1.1.0/24 through the path Device
C<—>Device D<—>Device A.
Example: Configuring BGP FRR
Network configuration
As shown in Figure 96 , configure BGP FRR so that when Link B fails, BGP uses Link A to forward
traffic.
Figure 96 Network diagram
Loop0
2.2.2.2/32
HGE1/0/1
10.1.1.2/24
HGE1/0/2
20.1.1.2/24
AS 200
Device A
HGE1/0/1
10.1.1.1/24
Device B
Link B
HGE1/0/1
20.1.1.4/24
Device D
AS 100 HGE1/0/2
30.1.1.1/24
HGE1/0/2
40.1.1.4/24
HGE1/0/1
30.1.1.3/24
Link A
Device C
HGE1/0/2
40.1.1.3/24
Loop0
3.3.3.3/32
442
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF in AS 200 to ensure connectivity among Device B, Device C, and Device D.
(Details not shown.)
3. Configure BGP connections:
# Configure Device A to establish EBGP sessions to Device B and Device C, and advertise network 1.1.1.1/32.
<DeviceA> system-view
[DeviceA] bgp 100
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 10.1.1.2 as-number 200
[DeviceA-bgp-default] peer 30.1.1.3 as-number 200
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] peer 10.1.1.2 enable
[DeviceA-bgp-default-ipv4] peer 30.1.1.3 enable
[DeviceA-bgp-default-ipv4] network 1.1.1.1 32
# Configure Device B to establish an EBGP session to Device A, and an IBGP session to
Device D.
<DeviceB> system-view
[DeviceB] bgp 200
[DeviceB-bgp-default] router-id 2.2.2.2
[DeviceB-bgp-default] peer 10.1.1.1 as-number 100
[DeviceB-bgp-default] peer 4.4.4.4 as-number 200
[DeviceB-bgp-default] peer 4.4.4.4 connect-interface loopback 0
[DeviceB-bgp-default] address-family ipv4 unicast
[DeviceB-bgp-default-ipv4] peer 10.1.1.1 enable
[DeviceB-bgp-default-ipv4] peer 4.4.4.4 enable
[DeviceB-bgp-default-ipv4] peer 4.4.4.4 next-hop-local
[DeviceB-bgp-default-ipv4] quit
[DeviceB-bgp-default] quit
# Configure Device C to establish an EBGP session to Device A, and an IBGP session to
Device D.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC-bgp-default] router-id 3.3.3.3
[DeviceC-bgp-default] peer 30.1.1.1 as-number 100
[DeviceC-bgp-default] peer 4.4.4.4 as-number 200
[DeviceC-bgp-default] peer 4.4.4.4 connect-interface loopback 0
[DeviceC-bgp-default] address-family ipv4 unicast
[DeviceC-bgp-default-ipv4] peer 30.1.1.1 enable
[DeviceC-bgp-default-ipv4] peer 4.4.4.4 enable
[DeviceC-bgp-default-ipv4] peer 4.4.4.4 next-hop-local
[DeviceC-bgp-default-ipv4] quit
443
[DeviceC-bgp-default] quit
# Configure Device D to establish IBGP sessions to Device B and Device C, and advertise network 4.4.4.4/32.
<DeviceD> system-view
[DeviceD] bgp 200
[DeviceD-bgp-default] router-id 4.4.4.4
[DeviceD-bgp-default] peer 2.2.2.2 as-number 200
[DeviceD-bgp-default] peer 2.2.2.2 connect-interface loopback 0
[DeviceD-bgp-default] peer 3.3.3.3 as-number 200
[DeviceD-bgp-default] peer 3.3.3.3 connect-interface loopback 0
[DeviceD-bgp-default] address-family ipv4 unicast
[DeviceD-bgp-default-ipv4] peer 2.2.2.2 enable
[DeviceD-bgp-default-ipv4] peer 3.3.3.3 enable
[DeviceD-bgp-default-ipv4] network 4.4.4.4 32
4. Configure preferred values so Link B is used to forward traffic between Device A and Device D:
# Configure Device A to set the preferred value to 100 for routes received from Device B.
[DeviceA-bgp-default-ipv4] peer 10.1.1.2 preferred-value 100
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# Configure Device D to set the preferred value to 100 for routes received from Device B.
[DeviceD-bgp-default-ipv4] peer 2.2.2.2 preferred-value 100
[DeviceD-bgp-default-ipv4] quit
[DeviceD-bgp-default] quit
5. Configure BGP FRR:
# On Device A, configure the source address of BFD echo packets as 11.1.1.1.
[DeviceA] bfd echo-source-ip 11.1.1.1
# Create routing policy frr to set a backup next hop 30.1.1.3 (Device C) for the route destined for 4.4.4.4/32.
[DeviceA] ip prefix-list abc index 10 permit 4.4.4.4 32
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy] if-match ip address prefix-list abc
[DeviceA-route-policy] apply fast-reroute backup-nexthop 30.1.1.3
[DeviceA-route-policy] quit
# Use BFD echo packet mode to detect the connectivity to Device D.
[DeviceA] bgp 100
[DeviceA-bgp-default] primary-path-detect bfd echo
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[DeviceA-bgp-default] address-family ipv4 unicast
[DeviceA-bgp-default-ipv4] fast-reroute route-policy frr
[DeviceA-bgp-default-ipv4] quit
[DeviceA-bgp-default] quit
# On Device D, set the source address of BFD echo packets to 44.1.1.1.
[DeviceD] bfd echo-source-ip 44.1.1.1
# Create routing policy frr to set a backup next hop 3.3.3.3 (Device C) for the route destined for
1.1.1.1/32.
[DeviceD] ip prefix-list abc index 10 permit 1.1.1.1 32
[DeviceD] route-policy frr permit node 10
[DeviceD-route-policy] if-match ip address prefix-list abc
444
[DeviceD-route-policy] apply fast-reroute backup-nexthop 3.3.3.3
[DeviceD-route-policy] quit
# Use BFD echo packet mode to detect the connectivity to Device A.
[DeviceD] bgp 200
[DeviceD-bgp-default] primary-path-detect bfd echo
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[DeviceD-bgp-default] address-family ipv4 unicast
[DeviceD-bgp-default-ipv4] fast-reroute route-policy frr
[DeviceD-bgp-default-ipv4] quit
[DeviceD-bgp-default] quit
Verifying the configuration
# Display detailed information about the route to 4.4.4.4/32 on Device A. The output shows the backup next hop for the route.
[DeviceA] display ip routing-table 4.4.4.4 32 verbose
Summary count : 1
Destination: 4.4.4.4/32
Protocol: BGP Process ID: 0
SubProtID: 0x2 Age: 00h01m52s
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 200
NibID: 0x15000003 LastAs: 200
AttrID: 0x5 Neighbor: 10.1.1.2
Flags: 0x10060 OrigNextHop: 10.1.1.2
Label: NULL RealNextHop: 10.1.1.2
BkLabel: NULL BkNextHop: 30.1.1.3
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/2
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display detailed information about the route to 1.1.1.1/32 on Device D. The output shows the backup next hop for the route.
[DeviceD] display ip routing-table 1.1.1.1 32 verbose
Summary count : 1
Destination: 1.1.1.1/32
Protocol: BGP Process ID: 0
SubProtID: 0x1 Age: 00h00m36s
445
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 100
NibID: 0x15000003 LastAs: 100
AttrID: 0x1 Neighbor: 2.2.2.2
Flags: 0x10060 OrigNextHop: 2.2.2.2
Label: NULL RealNextHop: 20.1.1.2
BkLabel: NULL BkNextHop: 40.1.1.3
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/2
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
IPv6 BGP network reliability improvement configuration examples
Example: Configuring BFD for IPv6 BGP
Network configuration
As shown in Figure 97 , configure OSPFv3 as the IGP in AS 200.
•
Establish two IBGP connections between Device A and Device C. When both paths operate correctly, Device C uses the path Device A<—>Device B<—>Device C to exchange packets with network 1200::0/64.
•
Configure BFD over the path. When the path fails, BFD can quickly detect the failure and notify it to IPv6 BGP. Then, the path Device A<—>Device D<—>Device C takes effect immediately.
Figure 97 Network diagram
Device B
HGE1/0/2
3001::1/64
HGE1/0/2
3001::2/64
AS 100 1200::0/64
Device A
HGE1/0/1
2001::1/64
AS 200
HGE1/0/1
3002::1/64
HGE1/0/1
3002::2/64
HGE1/0/2
Device C
2002::2/64
HGE1/0/1
2001::2/64
HGE1/0/2
2002::1/64
Device D
446
AS 300
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 so that Device A and Device C can reach each other. (Details not shown.)
3. Configure IPv6 BGP on Device A:
# Establish two IBGP connections to Device C.
<DeviceA> system-view
[DeviceA] bgp 200
[DeviceA-bgp-default] router-id 1.1.1.1
[DeviceA-bgp-default] peer 2002::2 as-number 200
[DeviceA-bgp-default] peer 3002::2 as-number 200
[DeviceA-bgp-default] address-family ipv6
[DeviceA-bgp-default-ipv6] peer 2002::2 enable
[DeviceA-bgp-default-ipv6] peer 3002::2 enable
[DeviceA-bgp-default-ipv6] quit
# Create IPv6 basic ACL 2000 to permit 1200::0/64 to pass.
[DeviceA] acl ipv6 basic 2000
[DeviceA-acl-ipv6-basic-2000] rule permit source 1200:: 64
[DeviceA-acl-ipv6-basic-2000] quit
# Create two routing policies to set the MED for route 1200::0/64. The policy apply_med_50 sets the MED to 50, and the policy apply_med_100 sets the MED to 100.
[DeviceA] route-policy apply_med_50 permit node 10
[DeviceA-route-policy-apply_med_50-10] if-match ipv6 address acl 2000
[DeviceA-route-policy-apply_med_50-10] apply cost 50
[DeviceA-route-policy-apply_med_50-10] quit
[DeviceA] route-policy apply_med_100 permit node 10
[DeviceA-route-policy-apply_med_100-10] if-match ipv6 address acl 2000
[DeviceA-route-policy-apply_med_100-10] apply cost 100
[DeviceA-route-policy-apply_med_100-10] quit
# Apply routing policy apply_med_50 to routes outgoing to peer 3002::2, and apply routing policy apply_med_100 to routes outgoing to peer 2002::2.
[DeviceA] bgp 200
[DeviceA-bgp-default] address-family ipv6 unicast
[DeviceA-bgp-default-ipv6] peer 3002::2 route-policy apply_med_50 export
[DeviceA-bgp-default-ipv6] peer 2002::2 route-policy apply_med_100 export
[DeviceA-bgp-default-ipv6] quit
# Enable BFD for peer 3002::2.
[DeviceA-bgp-default] peer 3002::2 bfd
[DeviceA-bgp-default] quit
4. Configure IPv6 BGP on Device C:
# Establish two IBGP connections to Device A.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC-bgp-default] router-id 3.3.3.3
447
[DeviceC-bgp-default] peer 3001::1 as-number 200
[DeviceC-bgp-default] peer 2001::1 as-number 200
[DeviceC-bgp-default] address-family ipv6
[DeviceC-bgp-default-ipv6] peer 3001::1 enable
[DeviceC-bgp-default-ipv6] peer 2001::1 enable
[DeviceC-bgp-default-ipv6] quit
# Enable BFD for peer 3001::1.
[DeviceC-bgp-default] peer 3001::1 bfd
[DeviceC-bgp-default] quit
[DeviceC] quit
Verifying the configuration
# Display detailed BFD session information on Device C.
<DeviceC> display bfd session verbose
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 Session Working in control packet mode:
Local Discr: 513 Remote Discr: 513
Source IP: 3002::2
Destination IP: 3001::1
Session State: Up Interface: N/A
Min Tx Inter: 500ms Act Tx Inter: 500ms
Min Rx Inter: 500ms Detect Inter: 2500ms
Rx Count: 13 Tx Count: 14
Connect Type: Indirect Running Up for: 00:00:05
Hold Time: 2243ms Auth mode: None
Detect Mode: Async Slot: 0
Protocol: BGP4+
Version:1
Diag Info: No Diagnostic
The output shows that a BFD session has been established between Device A and Device C.
# Display BGP peer information on Device C.
<DeviceC> display bgp peer ipv6
BGP local router ID: 3.3.3.3
Local AS number: 200
Total number of peers: 2 Peers in established state: 2
* - Dynamically created peer
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
2001::1 200 8 8 0 0 00:04:45 Established
3001::1 200 5 4 0 0 00:01:53 Established
The output shows that Device C has established two BGP connections with Device A, and both connections are in Established state.
# Display route 1200::0/64 on Device C.
<DeviceC> display ipv6 routing-table 1200::0 64 verbose
448
Summary count : 1
Destination: 1200::/64
Protocol: BGP4+ Process ID: 0
SubProtID: 0x1 Age: 00h01m07s
Cost: 50 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x25000001 LastAs: 0
AttrID: 0x1 Neighbor: 3001::1
Flags: 0x10060 OrigNextHop: 3001::1
Label: NULL RealNextHop: FE80::20C:29FF:FE4A:3873
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device C communicates with network 1200::0/64 through the path Device
C<—>Device B<—>Device A.
# Break down the path Device C<—>Device B<—>Device A and then display route 1200::0/64 on
Device C.
<DeviceC> display ipv6 routing-table 1200::0 64 verbose
Summary count : 1
Destination: 1200::/64
Protocol: BGP4+ Process ID: 0
SubProtID: 0x1 Age: 00h00m57s
Cost: 100 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x25000000 LastAs: 0
AttrID: 0x0 Neighbor: 2001::1
Flags: 0x10060 OrigNextHop: 2001::1
Label: NULL RealNextHop: FE80::20C:29FF:FE40:715
BkLabel: NULL BkNextHop: N/A
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
449
BkTunnel ID: Invalid BkInterface: N/A
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
The output shows that Device C communicates with network 1200::0/64 through the path Device
C<—>Device D<—>Device A.
Example: Configuring IPv6 BGP FRR
Network configuration
As shown in Figure 98 , configure BGP FRR so that when Link B fails, BGP uses Link A to forward
traffic.
Figure 98 Network diagram
Loop0
2.2.2.2/32
HGE1/0/1
3001::2/64
HGE1/0/2
3002::1/64
AS 200
Device A
HGE1/0/1
3001::1/64
Device B
Link B
HGE1/0/1
3002::2/64
Device D
AS 100
HGE1/0/2
2001::1/64
HGE1/0/1
2001::2/64
Link A
Device C
HGE1/0/2
2002::1/64
HGE1/0/2
2002::2/64
Loop0
3.3.3.3/32
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 in AS 200 to ensure connectivity among Device B, Device C, and Device D.
(Details not shown.)
3. Configure BGP connections:
# Configure Device A to establish EBGP sessions to Device B and Device C, and advertise network 1::/64.
<DeviceA> system-view
[DeviceA] bgp 100
[DeviceA] router-id 1.1.1.1
[DeviceA-bgp-default] peer 3001::2 as-number 200
[DeviceA-bgp-default] peer 2001::2 as-number 200
450
[DeviceA-bgp-default] address-family ipv6 unicast
[DeviceA-bgp-default-ipv6] peer 3001::2 enable
[DeviceA-bgp-default-ipv6] peer 2001::2 enable
[DeviceA-bgp-default-ipv6] network 1:: 64
[DeviceA-bgp-default-ipv6] quit
[DeviceA-bgp-default] quit
# Configure Device B to establish an EBGP session to Device A, and an IBGP session to
Device D.
<DeviceB> system-view
[DeviceB] bgp 200
[DeviceB] router-id 2.2.2.2
[DeviceB-bgp-default] peer 3001::1 as-number 100
[DeviceB-bgp-default] peer 3002::2 as-number 200
[DeviceB-bgp-default] address-family ipv6 unicast
[DeviceB-bgp-default-ipv6] peer 3001::1 enable
[DeviceB-bgp-default-ipv6] peer 3002::2 enable
[DeviceB-bgp-default-ipv6] peer 3002::2 next-hop-local
[DeviceB-bgp-default-ipv6] quit
[DeviceB-bgp-default] quit
# Configure Device C to establish an EBGP session to Device A, and an IBGP session to
Device D.
<DeviceC> system-view
[DeviceC] bgp 200
[DeviceC] router-id 3.3.3.3
[DeviceC-bgp-default] peer 2001::1 as-number 100
[DeviceC-bgp-default] peer 2002::2 as-number 200
[DeviceC-bgp-default] address-family ipv6 unicast
[DeviceC-bgp-default-ipv6] peer 2001::1 enable
[DeviceC-bgp-default-ipv6] peer 2002::2 enable
[DeviceC-bgp-default-ipv6] peer 2002::2 next-hop-local
[DeviceC-bgp-default-ipv6] quit
[DeviceC-bgp-default] quit
# Configure Device D to establish IBGP sessions to Device B and Device C, and advertise network 4::/64.
<DeviceD> system-view
[DeviceD] bgp 200
[DeviceD-bgp-default] peer 3002::1 as-number 200
[DeviceD-bgp-default] peer 2002::1 as-number 200
[DeviceD-bgp-default] address-family ipv6 unicast
[DeviceD-bgp-default-ipv6] peer 3002::1 enable
[DeviceD-bgp-default-ipv6] peer 2002::1 enable
[DeviceD-bgp-default-ipv6] network 4:: 64
[DeviceD-bgp-default-ipv6] quit
[DeviceD-bgp-default] quit
4. Configure preferred values so Link B is used to forward traffic between Device A and Device D:
# Configure Device A to set the preferred value to 100 for routes received from Device B.
[DeviceA-bgp-default-ipv6] peer 3001::2 preferred-value 100
[DeviceA-bgp-default-ipv6] quit
451
[DeviceA-bgp-default] quit
# Configure Device D to set the preferred value to 100 for routes received from Device B.
[DeviceD-bgp-default-ipv6] peer 3002::1 preferred-value 100
[DeviceD-bgp-default-ipv6] quit
[DeviceD-bgp-default] quit
5. Configure BGP FRR:
# On Device A, create routing policy frr to set a backup next hop 2001::2 (Device C) for the route destined for 4::/64.
<DeviceA> system-view
[DeviceA] ipv6 prefix-list abc index 10 permit 4:: 64
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy] if-match ipv6 address prefix-list abc
[DeviceA-route-policy] apply ipv6 fast-reroute backup-nexthop 2001::2
[DeviceA-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv6 unicast address family.
[DeviceA] bgp 100
[DeviceA-bgp-default] address-family ipv6 unicast
[DeviceA-bgp-default-ipv6] fast-reroute route-policy frr
[DeviceA-bgp-default-ipv6] quit
[DeviceA-bgp-default] quit
# On Device D, create routing policy frr to set a backup next hop 2002::1 (Device C) for the route destined for 1::/64.
<DeviceD> system-view
[DeviceD] ipv6 prefix-list abc index 10 permit 1:: 64
[DeviceD] route-policy frr permit node 10
[DeviceD-route-policy] if-match ipv6 address prefix-list abc
[DeviceD-route-policy] apply ipv6 fast-reroute backup-nexthop 2002::1
[DeviceD-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv6 unicast address family.
[DeviceD] bgp 200
[DeviceD-bgp-default] address-family ipv6 unicast
[DeviceD-bgp-default-ipv6] fast-reroute route-policy frr
[DeviceD-bgp-default-ipv6] quit
[DeviceD-bgp-default] quit
Verifying the configuration
# Display detailed information about the route to 4::/64 on Device A. The output shows the backup next hop for the route.
[DeviceA] display ipv6 routing-table 4:: 64 verbose
Summary count : 1
Destination: 4::/64
Protocol: BGP4+ Process ID: 0
SubProtID: 0x2 Age: 00h00m58s
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
452
TableID: 0xa OrigAs: 200
NibID: 0x25000003 LastAs: 200
AttrID: 0x3 Neighbor: 3001::2
Flags: 0x10060 OrigNextHop: 3001::2
Label: NULL RealNextHop: 3001::2
BkLabel: NULL BkNextHop: 2001::2
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/2
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display detailed information about the route to 1::/64 on Device D. The output shows the backup next hop for the route.
[DeviceD] display ipv6 routing-table 1:: 64 verbose
Summary count : 1
Destination: 1::/64
Protocol: BGP4+ Process ID: 0
SubProtID: 0x1 Age: 00h03m24s
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0xa OrigAs: 100
NibID: 0x25000003 LastAs: 100
AttrID: 0x4 Neighbor: 3002::1
Flags: 0x10060 OrigNextHop: 3002::1
Label: NULL RealNextHop: 3002::1
BkLabel: NULL BkNextHop: 2002::1
SRLabel: NULL BKSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/1
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/2
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
453
Configuring extended BGP features
Extended BGP feature configuration tasks at a glance
To configure extended BGP features, perform the following tasks:
•
•
(Optional.) Configuring BGP LS route reflection
(Optional.) Specifying an AS number and a router ID for BGP LS messages
(Optional.) Performing manual soft-reset for BGP sessions of LS address family
•
Configuring the BGP Additional Paths feature for 6PE
(Optional.) Controlling path selection for 6PE
(Optional.) Controlling 6PE route advertisement and reception
(Optional.) Tuning and optimizing 6PE
(Optional.) Configuring 6PE route reflection
(Optional.) Resetting 6PE connections
Configuring BMP
About this task
The BGP monitoring protocol (BMP) enables a BGP router (BMP client) to send session status information of the specified peers to BMP servers for monitoring. The session status information includes peer relationship establishment and termination as well as routing information. The BMP client communicates with the BMP servers through TCP connections.
Procedure
1. Enter system view. system-view
2. Create a BMP server and enter BMP server view. bmp server server-number
3. Configure an IP address and port number for the BMP server. server address ipv4-address port port-number
By default, no IP address and port number are configured for the BMP server.
4. Set the interval at which BGP sends statistics information to the BMP server.
statistics-interval value
By default, BGP does not send statistics information to the BMP server.
5. (Optional.) Specify a VPN instance for the BMP server. server vpn-instance vpn-instance-name
454
By default, no VPN instance is specified for a BMP server. A BMP server belongs to the public network.
6. (Optional.) Specify the source interface of TCP connections to the BMP server.
server connect-interface interface-type interface-number
By default, BGP uses the primary IPv4 address of the output interface in the optimal route to the
BMP server as the source address of TCP connections to the BMP server.
For a BMP server, this command does not take effect if the VPN instance of the specified interface is different from that specified by the server vpn-instance command.
7. (Optional.) Specify the authentication mode and key for the local device to establish TCP connections to the BMP server. server password { keychain keychain-name | md5 { cipher | simple }
string }
By default, the local device establishes TCP connections to the BMP server without authentication.
8. (Optional.) Enable BGP to send routes to the BMP server globally. Choose the options to configure as needed:
Enable BGP to send routes advertised to all the monitored peers and peer groups to the
BMP server. route-mode adj-rib-out [ pre-policy | post-policy | both ]
By default, BGP does not send routes advertised to a monitored peer or peer group to the
BMP server.
Enable BGP to send routes received from all the monitored peers and peer groups to the
BMP server.
route-mode adj-rib-in [ pre-policy | post-policy | both ]
By default, BGP does not send routes received from a monitored peer or peer group to the
BMP server.
Configure BGP to send the optimal routes in the routing table to the BMP server. route-mode loc-rib
By default, BGP does not send the optimal routes in the routing table to the BMP server.
With this feature configured, BGP sends all routes to the BMP server first. If routes update later, BGP sends only the optimal routes to the server.
9. Return to system view. quit
10. Enter BGP instance view or BGP-VPN instance view.
Enter BGP instance view.
bgp as-number [ instance instance-name ]
Enter BGP-VPN instance view.
bgp as-number [ instance instance-name ]
ip vpn-instance vpn-instance-name
11. Specify a peer or peer group to be monitored. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } bmp server server-number-list
By default, no peer or peer group is specified.
If you execute this command multiple times for a peer or peer group, the most recent configuration takes effect.
12. (Optional.) Enable BGP to send routes exchanged with the specified monitored peer or peer group to the BMP server.
455
peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } route-mode { adj-rib-in { pre-policy | post-policy
| both } | adj-rib-out { pre-policy | post-policy | both } } *
By default, BGP determines whether to send routes exchanged with a peer or peer group to the
BMP server based on the following configurations:
Configuration of the route-mode adj-rib-in command in BMP server view.
Configuration of the route-mode adj-rib-out command in BMP server view.
Verifying and maintaining BMP
To display BMP server information, execute the following command in any view: display bgp [ instance instance-name ] bmp server server-number
To clear BMP server statistics, execute the following command in user view: reset bgp [ instance instance-name ] bmp server server-number statistics
Configuring BGP LS
About BGP LS
The BGP Link State (LS) feature implements inter-domain and inter-AS advertisement of link state database (LSDB) and TE database (TEDB) information.
The device sends the collected link state information to the controller, which implements end-to-end traffic management and scheduling and meets the requirements of intended applications.
Configuring basic BGP LS
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Specify an AS number for an LS peer or peer group. peer { { ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] }
| group-name } as-number as-number
By default, no AS number is specified.
4. Create the BGP LS address family and enter its view. address-family link-state
5. Enable the device to exchange LS information with the peer or peer group. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } enable
By default, the device cannot exchange LS information with the peer or peer group.
Configuring BGP LS route reflection
About this task
Perform this task to configure a BGP route reflector and its clients. The route reflector and its clients automatically form a cluster identified by the router ID of the route reflector. The route reflector forwards route updates among its clients.
456
Procedure
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP LS address family view. address-family link-state
4. Configure BGP LS route reflection.
Configure the device as a route reflector and specify a peer or peer group as its client. peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } reflect-client
By default, no route reflector or client is configured.
(Optional.) Enable route reflection between clients. reflect between-clients
By default, route reflection between clients is enabled.
This command can reduce the number of IBGP connections in an AS.
(Optional.) Configure the cluster ID of the route reflector. reflector cluster-id { cluster-id | ipv4-address }
By default, a route reflector uses its own router ID as the cluster ID.
Specifying an AS number and a router ID for BGP LS messages
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP LS address family view. address-family link-state
4. Specify an AS number and a router ID for BGP LS messages.
domain-distinguisher as-number:router-id
By default, the AS number and router ID of the current BGP process are used.
Configure this command to ensure that LS messages sent by devices in the same AS have the same AS number and router ID.
Performing manual soft-reset for BGP sessions of LS address family
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Enable BGP route refresh.
Enable BGP route refresh for a peer or peer group.
457
peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } capability-advertise route-refresh
Enable the BGP route refresh, multi-protocol extension, and 4-byte AS number features for a peer or peer group. undo peer { group-name | ipv4-address [ mask-length ] | ipv6-address
[ prefix-length ] } capability-advertise conventional
By default, the BGP route refresh, multi-protocol extension, and 4-byte AS number features are enabled.
4. Perform manual soft-reset for BGP sessions of LS address family: a. Return to system view. quit b. Return to user view. quit c. Perform manual soft-reset for BGP sessions of LS address family. refresh bgp [ instance instance-name ] { ipv4-address [ mask-length ]
| ipv6-address [ prefix-length ] | all | external | group group-name
| internal } { export | import } link-state
Verifying and maintaining BGP LS
Verifying BGP LS configuration and running status
Perform display tasks in any view.
•
Display BGP LS peer group information. display bgp [ instance instance-name ] group link-state [ group-name group-name ]
•
Display BGP LS peer or peer group information. display bgp [ instance instance-name ] peer link-state [ ipv4-address mask-length | ipv6-address prefix-length | { ipv4-address | ipv6-address |
group-name group-name } log-info | [ ipv4-address | ipv6-address ] verbose ]
•
Display BGP LS address family information. display bgp [ instance instance-name ] link-state [ ls-prefix | peer
{ ipv4-address | ipv6-address } { advertised | received } [ statistics ] | statistics ]
•
Display BGP update group information for the LS address family. display bgp [ instance instance-name ] update-group link-state
[ ipv4-address | ipv6-address ]
Resetting BGP session in the LS address family
To reset BGP sessions in the LS address family, execute the following command in user view: reset bgp [ instance instance-name ] { as-number | ipv4-address
[ mask-length ] | ipv6-address [ prefix-length ] | all | external | group group-name | internal } link-state
458
Configuring 6PE
About 6PE
IPv6 provider edge (6PE) is a transition technology that uses MPLS to connect sparsely populated
IPv6 networks through an existing IPv4 backbone network. It is an efficient solution for ISP
IPv4/MPLS networks to provide IPv6 traffic switching capability.
Figure 99 Network diagram for 6PE
CE
IPv4/MPLS network
CE
IBGP
IPv6 network
Customer site
6PE 6PE IPv6 network
Customer site
P
6PE mainly performs the following operations:
•
6PE assigns a label to IPv6 routing information received from a CE router, and sends the labeled IPv6 routing information to the peer 6PE device through an MP-BGP session. The peer
6PE device then forwards the IPv6 routing information to the attached customer site.
•
6PE provides tunnels over the IPv4 backbone so the IPv4 backbone can forward packets for
IPv6 networks. The tunnels can be GRE tunnels, MPLS LSPs, or MPLS TE tunnels.
•
Upon receiving an IPv6 packet, 6PE adds an inner tag (corresponding to the IPv6 packet) and then an outer tag (corresponding to the public network tunnel) to the IPv6 packet. Devices in the
IPv4 backbone network forwards the packet based on the outer tag. When the peer 6PE device receives the packet, it removes the outer and inner tags and forwards the original IPv6 packet to the attached customer site.
To implement exchange of IPv6 routing information, you can configure IPv6 static routing, an IPv6
IGP protocol, or IPv6 BGP between CE and 6PE devices.
For more information about MPLS, MPLS TE, CE, and P, see MPLS Configuration Guide . For more information about GRE, see Layer 3—IP Services Configuration Guide .
Prerequisites
Before you configure 6PE, perform the following tasks:
•
Establish tunnels in the IPv4 backbone network (see Layer 3—IP Services Configuration
Guide ).
•
Configure basic MPLS on 6PE devices (see MPLS Configuration Guide ).
•
Configure BGP on 6PE devices so that they can advertise tagged IPv6 routing information through BGP sessions. The following tasks describe only BGP configurations on 6PE devices.
Configuring basic 6PE
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
459
3. Specify a 6PE peer or peer group and its AS number. peer { group-name | ipv4-address [ mask-length ] } as-number as-number
By default, no 6PE peer is specified.
4. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
5. Enable BGP to exchange IPv6 unicast routing information with the 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } enable
By default, BGP cannot exchange IPv6 unicast routing information with a 6PE peer or peer group.
6. Enable BGP to exchange labeled IPv6 routes with the 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } label-route-capability
By default, BGP cannot exchange labeled IPv6 routes with a 6PE peer or peer group.
Configuring the BGP Additional Paths feature for 6PE
1. Enter system view. system-view
2. Enter BGP instance view.
bgp as-number [ instance instance-name ]
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Configure the BGP Additional Paths capabilities for a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } additional-paths
{ receive | send } *
By default, no BGP Additional Paths capabilities are configured for a 6PE peer or peer group.
5. Set the maximum number of Add-Path optimal routes that can be advertised to a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } advertise
additional-paths best number
By default, BGP does not advertise Add-Path optimal routes to a 6PE peer or peer group.
Controlling path selection for 6PE
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Advertise COMMUNITY attribute to a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } advertise-community
By default, the COMMUNITY attribute is not advertised.
5. Advertise extended community attribute to a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } advertise-ext-community
460
By default, the extended community attribute is not advertised.
6. Remove private AS numbers in BGP updates sent to a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } public-as-only
By default, BGP updates sent to a 6PE peer or peer group can carry both public and private AS numbers.
7. Specify a preferred value for routes received from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } preferred-value value
By default, the preferred value for routes received from a 6PE peer or peer group is 0.
8. Enable BGP to add the link bandwidth attribute to routes received from a 6PE peer or peer group. peer { group-name | ipv6-address [ prefix-length ] } bandwidth
By default, BGP does not add the link bandwidth attribute to routes received from a 6PE peer or peer group.
9. Configure BGP to advertise the AIGP attribute to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } aigp
By default, BGP does not advertise the AIGP attribute to a peer or peer group.
10. Replace the MED value with AIGP value in routes advertised to the specified peer or peer group. peer { group-name | ipv4-address [ mask-length ] } aigp send med
By default, BGP does not replace the MED value with AIGP value in routes advertised to a peer or peer group.
Controlling 6PE route advertisement and reception
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Advertise a default route to a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } default-route-advertise [ route-policy route-policy-name ]
By default, no default route is advertised to a 6PE peer or peer group.
5. Configure route filtering policies.
Specify an AS path list to filter routes advertised to or received from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } as-path-acl
{ as-path-acl-number | as-path-acl-name } { export | import }
By default, no AS path list is specified.
Specify an IPv6 ACL to filter routes advertised to or received from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } filter-policy
{ ipv6-acl-number | name ipv6-acl-name } { export | import }
By default, no IPv6 ACL is specified.
Specify an IPv6 prefix list to filter routes advertised to or received from a 6PE peer or peer group.
461
peer { group-name | ipv4-address [ mask-length ] } prefix-list ipv6-prefix-list-name { export | import }
By default, no IPv6 prefix list is specified.
Specify a routing policy to filter routes advertised to or received from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } route-policy route-policy-name { export | import }
By default, no routing policy is specified.
6. Save all routes from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } keep-all-routes
By default, routes from a 6PE peer or peer group are not saved.
7. Set the maximum number of routes that BGP can receive from a 6PE peer or peer group. peer { group-name | ipv4-address [ mask-length ] } route-limit prefix-number [ { alert-only | discard | reconnect reconnect-time } | percentage-value ] *
By default, the number of routes that BGP can receive from a 6PE peer or peer group is not limited.
8. Configure the SoO attribute for a peer or peer group. peer { group-name | ipv4-address [ mask-length ] } soo site-of-origin
By default, no SoO attribute is configured for a peer or peer group.
Tuning and optimizing 6PE
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Allow the local AS number to appear in routes from a 6PE peer or peer group and specify the repeat times. peer { group-name | ipv4-address [ mask-length ] } allow-as-loop
[ number ]
By default, the local AS number is not allowed to appear in routes from a 6PE peer or peer group.
Configuring 6PE route reflection
1. Enter system view. system-view
2. Enter BGP instance view. bgp as-number [ instance instance-name ]
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Configure the device as a route reflector and a 6PE peer or peer group as a client. peer { group-name | ipv4-address [ mask-length ] } reflect-client
462
By default, no route reflector or client is configured.
Resetting 6PE connections
To reset 6PE connections, execute one of the following commands in user view:
•
Soft-reset a BGP 6PE connection.
refresh bgp [ instance instance-name ] ipv4-address [ mask-length ]
{ export | import } ipv6 [ unicast ]
•
Reset a BGP 6PE connection.
reset bgp [ instance instance-name ] ipv4-address [ mask-length ] ipv6
[ unicast ]
CAUTION:
A reset operation tears down BGP sessions for a short period of time.
Extended IPv4 BGP feature configuration examples
Example: Configuring BGP LS
Network configuration
As shown in Figure 100 , all devices run BGP. Run IBGP between Device A and Device B, between
Device B and Device C, and between Device B and Device D.
Configure Device B as a route reflector with client Device A to allow Device A to learn LS information advertised by Device C and Device D.
Figure 100 Network diagram
Device C
Device A
HGE1/0/1
192.1.1.1/24
HGE1/0/3
192.1.1.2/24
HGE
1/0/1
/24
193.
1.1.1
Device B
HGE
1/0/1
193.
1.1.2
/24
HGE
1/0/2
.2/24
HGE
194.1.1
1/0/2
.1/24
Device D
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces and configure OSPF on Device C and Device D. (Details not shown.)
2. Configure BGP connections:
463
# Configure Device A.
<DeviceA> system-view
[DeviceA] bgp 100
[DeviceA-bgp-default] peer 192.1.1.2 as-number 100
[DeviceA-bgp-default] address-family link-state
[DeviceA-bgp-default-ls] peer 192.1.1.2 enable
[DeviceA-bgp-default-ls] quit
[DeviceA-bgp-default] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] bgp 100
[DeviceB-bgp-default] peer 192.1.1.1 as-number 100
[DeviceB-bgp-default] peer 193.1.1.1 as-number 100
[DeviceB-bgp-default] peer 194.1.1.1 as-number 100
[DeviceB-bgp-default] address-family link-state
[DeviceB-bgp-default-ls] peer 192.1.1.1 enable
[DeviceB-bgp-default-ls] peer 193.1.1.1 enable
[DeviceB-bgp-default-ls] peer 194.1.1.1 enable
[DeviceB-bgp-default-ls] quit
[DeviceB-bgp-default] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] bgp 100
[DeviceC-bgp-default] peer 193.1.1.2 as-number 100
[DeviceC-bgp-default] address-family link-state
[DeviceC-bgp-default-ls] peer 193.1.1.2 enable
[DeviceC-bgp-default-ls] quit
[DeviceC-bgp-default] quit
[DeviceC] ospf
[DeviceC-ospf-1] distribute bgp-ls
[DeviceC-ospf-1] area 0
[DeviceC-ospf-1-area-0.0.0.0] network 0.0.0.0 0.0.0.0
[DeviceC-ospf-1-area-0.0.0.0] quit
[DeviceC-ospf-1] quit
# Configure Device D.
<DeviceD> system-view
[DeviceD] bgp 100
[DeviceD-bgp-default] peer 194.1.1.2 as-number 100
[DeviceD-bgp-default] address-family link-state
[DeviceD-bgp-default-ls] peer 194.1.1.2 enable
[DeviceD-bgp-default-ls] quit
[DeviceD-bgp-default] quit
[DeviceD] ospf
[DeviceD-ospf-1] distribute bgp-ls
[DeviceD-ospf-1] area 0
[DeviceD-ospf-1-area-0.0.0.0] network 0.0.0.0 0.0.0.0
[DeviceD-ospf-1-area-0.0.0.0] quit
[DeviceD-ospf-1] quit
464
3. Configure Device B as the route reflector.
[DeviceB] bgp 100
[DeviceB-bgp-default] address-family link-state
[DeviceB-bgp-default-ls] peer 192.1.1.1 reflect-client
[DeviceB-bgp-default-ls] quit
[DeviceB-bgp-default] quit
Verifying the configuration
# Verify that Device A has learned LS information advertised by Device C and Device D.
[ DeviceA ] display bgp link-state
Total number of routes: 4
BGP local router ID is 192.1.1.1
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
Prefix codes: E link, V node, T IP reachable route, u/U unknown,
I Identifier, N local node, R remote node, L link, P prefix,
L1/L2 ISIS level-1/level-2, O OSPF, D direct, S static,
a area-ID, , l link-ID, t topology-ID, s ISO-ID,
c confed-ID/ASN, b bgp-identifier, r router-ID,
i if-address, n peer-address, o OSPF Route-type, p IP-prefix
d designated router address i Network : [ V ][ O ][ I0x0 ][ N [ c100 ][ b193.1.1.1
][ a0.0.0.0
][ r193.1.1.1
]] /376
NextHop : 193.1.1.1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED :
Path/Ogn: i i Network : [ V ][ O ][ I0x0 ][ N [ c100 ][ b194.1.1.1
][ a0.0.0.0
][ r194.1.1.1
]] /376
NextHop : 194.1.1.1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED :
Path/Ogn: i i Network :
[ T ][ O ][ I0x0 ][ N [ c100 ][ b193.1.1.1
][ a0.0.0.0
][ r193.1.1.1
]][ P [ o0x1 ][ p193.1.1.0/24 ]] /
480
NextHop : 193.1.1.1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED :
Path/Ogn: i i Network :
[ T ][ O ][ I0x0 ][ N [ c100 ][ b194.1.1.1
][ a0.0.0.0
][ r194.1.1.1
]][ P [ o0x1 ][ p194.1.1.0/24 ]] /
480
NextHop : 194.1.1.1 LocPrf : 100
465
PrefVal : 0 OutLabel : NULL
MED :
Path/Ogn: i
Extended IPv6 BGP feature configuration examples
Example: Configuring 6PE
Network configuration
Use 6PE to connect two isolated IPv6 networks over an IPv4/MPLS network.
•
The ISP uses OSPF as the IGP.
•
PE 1 and PE 2 are edge devices of the ISP, and establish an IPv4 IBGP connection between them.
•
CE 1 and CE 2 are edge devices of the IPv6 networks, and they connect the IPv6 networks to the ISP.
•
A CE and a PE exchange IPv6 packets through IPv6 static routing.
Figure 101 Network diagram
Loop0
1::1/128
HGE1/0/1
10::2/64
HGE1/0/1
10::1/64
CE 1
Loop0
2.2.2.2/32
HGE1/0/2
1.1.1.1/16
AS 65100
HGE1/0/2
1.1.1.2/16
Loop0
3.3.3.3/32
PE 1
IBGP
IPv4/MPLS network
PE 2
HGE1/0/1
20::2/64
Loop0
4::4/128
HGE1/0/1
20::1/64
CE 2
IPv6 network IPv6 network
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses and IPv4 addresses for interfaces. (Details not shown.)
2. Configure PE 1:
# Enable LDP globally, and configure the LSP generation policy.
<PE1> system-view
[PE1] mpls lsr-id 2.2.2.2
[PE1] mpls ldp
[PE1-ldp] lsp-trigger all
[PE1-ldp] quit
466
# Enable MPLS and LDP on HundredGigE 1/0/2.
[PE1] interface hundredgige 1/0/2
[PE1-HundredGigE1/0/2] mpls enable
[PE1-HundredGigE1/0/2] mpls ldp enable
[PE1-HundredGigE1/0/2] quit
# Configure IBGP, enable the peer's 6PE capabilities, and redistribute IPv6 direct and static routes.
[PE1] bgp 65100
[PE1-bgp-default] router-id 2.2.2.2
[PE1-bgp-default] peer 3.3.3.3 as-number 65100
[PE1-bgp-default] peer 3.3.3.3 connect-interface loopback 0
[PE1-bgp-default] address-family ipv6
[PE1-bgp-default-ipv6] import-route direct
[PE1-bgp-default-ipv6] import-route static
[PE1-bgp-default-ipv6] peer 3.3.3.3 enable
[PE1-bgp-default-ipv6] peer 3.3.3.3 label-route-capability
[PE1-bgp-default-ipv6] quit
[PE1-bgp-default] quit
# Configure the static route to CE 1.
[PE1] ipv6 route-static 1::1 128 10::1
# Configure OSPF for the ISP.
[PE1] ospf
[PE1-ospf-1] area 0
[PE1-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[PE1-ospf-1-area-0.0.0.0] network 1.1.0.0 0.0.255.255
[PE1-ospf-1-area-0.0.0.0] quit
[PE1-ospf-1] quit
3. Configure PE 2:
# Enable LDP globally, and configure the LSP generation policy.
<PE2> system-view
[PE2] mpls lsr-id 3.3.3.3
[PE2] mpls ldp
[PE2-mpls-ldp] lsp-trigger all
[PE2-mpls-ldp] quit
# Enable MPLS and LDP on HundredGigE 1/0/2.
[PE2] interface hundredgige 1/0/2
[PE2-HundredGigE1/0/2] mpls enable
[PE2-HundredGigE1/0/2] mpls ldp enable
[PE2-HundredGigE1/0/2] quit
# Configure IBGP, enable the peer's 6PE capabilities, and redistribute IPv6 direct and static routes.
[PE2] bgp 65100
[PE2-bgp-default] router-id 3.3.3.3
[PE2-bgp-default] peer 2.2.2.2 as-number 65100
[PE2-bgp-default] peer 2.2.2.2 connect-interface loopback 0
[PE2-bgp-default] address-family ipv6
[PE2-bgp-default-ipv6] import-route direct
[PE2-bgp-default-ipv6] import-route static
467
[PE2-bgp-default-ipv6] peer 2.2.2.2 enable
[PE2-bgp-default-ipv6] peer 2.2.2.2 label-route-capability
[PE2-bgp-default-ipv6] quit
[PE2-bgp-default] quit
# Configure the static route to CE 2.
[PE2] ipv6 route-static 4::4 128 20::1
# Configure OSPF for the ISP.
[PE2] ospf
[PE2-ospf-1] area 0
[PE2-ospf-1-area-0.0.0.0] network 3.3.3.3 0.0.0.0
[PE2-ospf-1-area-0.0.0.0] network 1.1.0.0 0.0.255.255
[PE2-ospf-1-area-0.0.0.0] quit
[PE2-ospf-1] quit
4. Configure a static route, with PE 1 as the default next hop.
<CE1> system-view
[CE1] ipv6 route-static :: 0 10::2
5. Configure a static route on CE 2, with PE 2 as the default next hop.
<CE2> system-view
[CE2] ipv6 route-static :: 0 20::2
Verifying the configuration
# Display the IPv6 BGP routing tables on PE 1 and PE 2. The output shows that each of them has two IPv6 network routes. The following shows the output on PE 1:
[ PE1 ] display bgp routing-table ipv6
Total number of routes: 5
BGP local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - dampened, h - history,
s - suppressed, S - stale, i - internal, e - external
a – additional-path
Origin: i - IGP, e - EGP, ? - incomplete
* > Network : 1::1 PrefixLen : 128
NextHop : 10::1 LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: ?
* >i Network : 4::4 PrefixLen : 128
NextHop : ::FFFF:3.3.3.3 LocPrf : 100
PrefVal : 0 OutLabel : 1279
MED : 0
Path/Ogn: ?
* > Network : 10:: PrefixLen : 64
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
468
Path/Ogn: ?
* > Network : 10::2 PrefixLen : 128
NextHop : ::1 LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: ?
* >i Network : 20:: PrefixLen : 64
NextHop : ::FFFF:3.3.3.3 LocPrf : 100
PrefVal : 0 OutLabel : 1278
MED : 0
Path/Ogn: ?
# Verify that CE 1 can ping the IPv6 address 4::4 (loopback interface address) of CE 2. (Details not shown.)
469
Configuring PBR
About PBR
Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify parameters for packets that match specific criteria such as ACLs. The parameters include the next hop, output interface, default next hop, and default output interface.
Packet forwarding process
When the device receives a packet, the device searches the PBR policy for a matching node to forward that packet.
•
If a matching node is found and its match mode is permit , the device performs the following operations: a. Uses the output interfaces or next hops specified on the node to forward the packet. b. Searches the routing table for a route (except the default route) to forward the packet if one of the following conditions exists:
−
No output interfaces or next hops are specified on the node.
−
Forwarding failed based on the output interfaces or next hops. c. Uses the default next hops or default output interfaces specified on the node to forward the packet if one of the following conditions exists:
−
No matching route was found in the routing table.
−
The routing table-based forwarding failed. d. Uses the default route to forward the packet if one of the following conditions exists:
−
No default next hops or default output interfaces are specified on the node.
−
The forwarding failed based on the default next hops or default output interfaces.
•
The device performs routing table lookup to forward the packet in either of the following conditions:
No matching node is found.
A matching node is found, but its match mode is deny .
PBR types
PBR includes the following types:
•
Local PBR —Guides the forwarding of locally generated packets, such as ICMP packets generated by using the ping command.
•
Interface PBR —Guides the forwarding of packets received on an interface.
Policy
A policy includes match criteria and actions to be taken on the matching packets. A policy can have one or multiple nodes as follows:
•
Each node is identified by a node number. A smaller node number has a higher priority.
•
A node contains if-match and apply clauses. An if-match clause specifies a match criterion, and an apply clause specifies an action.
470
•
A node has a match mode of permit or deny .
A policy compares packets with nodes in ascending order of node numbers. If a packet matches the criteria on a node, it is processed by the action on the node. If the packet does not match any criteria on the node, it goes to the next node for a match. If the packet does not match the criteria on any node, the device performs a routing table lookup.
Relationship between if-match clauses
Only the if-match acl clause is supported. On a node, you can specify only one if-match acl clause.
Relationship between apply clauses
You can specify multiple apply clauses for a node, but some of them might not be executed. For more information about relationship between apply
clauses, see " Configuring actions for a node ."
Relationship between the match mode and clauses on the node
Does a packet match all the if-match clauses on the node?
Yes.
No.
Match mode
Permit
•
If the node contains apply clauses, PBR executes the apply clauses on the node.
If PBR-based forwarding succeeds, PBR does not compare the packet with the next node.
If PBR-based forwarding fails,
PBR does not compare the packet with the next node.
•
If the node does not contain apply clauses, the device performs a routing table lookup for the packet.
Deny
The device performs a routing table lookup for the packet.
PBR compares the packet with the next node.
PBR compares the packet with the next node.
NOTE:
A node that has no if-match clauses matches any packet.
PBR and Track
PBR can work with the Track feature to dynamically adapt the availability status of an apply clause to the link status of a tracked object. The tracked object can be a next hop, output interface, default next hop, or default output interface.
•
When the track entry associated with an object changes to Negative , the apply clause is invalid.
•
When the track entry changes to Positive or NotReady , the apply clause is valid.
For more information about Track-PBR collaboration, see High Availability Configuration Guide .
471
Restrictions and guidelines: PBR configuration
If a packet destined for the local device matches a PBR policy, PBR will execute the apply clauses in the policy, including the clause for forwarding. When you configure a PBR policy, be careful to avoid this situation.
When you deploy a new PBR policy after a card restarts, follow these guidelines:
•
If you deploy a new PBR policy that has a larger match range than the original PBR policy on an interface of the same type, the following rules apply:
Traffic that matches the original PBR policy on the current interface will suffer temporary packet loss before the new PBR policy is deployed successfully.
After the new PBR policy is deployed successfully, traffic forwarding on the current interface will restore to normal.
•
When you deploy a new PBR policy on an interface of a different type, the following rules apply:
Traffic that matches the original PBR policy on the current interface will suffer temporary packet loss before the new PBR policy is deployed successfully.
After the new PBR policy is deployed successfully, traffic forwarding on the current interface will restore to normal.
As a best practice to avoid traffic loss caused by PBR policy changes, configure match criteria thoroughly when you configure the first PBR policy.
PBR tasks at a glance
To configure PBR, perform the following tasks:
1.
a.
b.
Setting match criteria for a node
c.
Configuring actions for a node
2.
Choose the following tasks as needed:
Specifying a policy for local PBR
Specifying a policy for interface PBR
3.
(Optional.) Enabling the PBR logging feature
Configuring a policy
Creating a node
1. Enter system view. system-view
2. Create a node for a policy, and enter its view. policy-based-route policy-name [ deny | permit ] node node-number
3. (Optional.) Configure a description for the policy node. description text
By default, no description is configured for a policy node.
472
Setting match criteria for a node
1. Enter system view. system-view
2. Enter policy node view. policy-based-route policy-name [ deny | permit ] node node-number
3. Set match criteria.
Set an ACL match criterion. if-match acl { acl-number | name acl-name }
By default, no ACL match criterion is set.
PBR supports both basic and advanced ACLs.
When using the ACL to match packets, PBR ignores the action ( permit or deny ) and time range settings in the ACL.
Configuring actions for a node
About this task
The apply clauses allow you to specify the actions to be taken on matching packets on a node.
The following apply clauses determine the packet forwarding paths in a descending order:
• apply access-vpn vpn-instance
•
• apply next-hop
• apply output-interface apply default-next-hop
• apply default-output-interface
PBR supports the types of apply
Table 24 Priorities and meanings of apply clauses
Clause apply precedence apply access-vpn vpn-instance apply remark-vpn apply output-interface and apply next-hop
Meaning
Sets an IP precedence.
Sets VPN instances.
Enables VPN remark action.
Sets output interfaces and next hops.
Priority
This clause is always executed.
If a packet matches a forwarding entry of a specified VPN instance, it is forwarded in the VPN instance.
VPN remark action applies only to packets that have been successfully forwarded based on the apply access-vpn vpn-instance command.
If both clauses are configured, only the apply next-hop clause is executed.
473
Clause apply default-next-hop and apply default-output-interface
Meaning
Sets default next hops and default output interface
Priority
If both clauses are configured, only the apply default-next-hop clause is executed.
The clauses take effect only in the following cases:
•
No output interfaces or next hops are set or the output interfaces and next hops are invalid.
•
The packet does not match any route in the routing table. apply statistics
Counts successful matches and matching bytes on the policy node.
To include the number of successful matches and matching bytes on a policy node in the statistics displayed by a display command, execute this command.
This clause is always executed for matching packets.
Restrictions and guidelines
If you specify a next hop or default next hop, PBR periodically performs a lookup in the FIB table to determine its availability. Temporary service interruption might occur if PBR does not update the route immediately after its availability status changes.
Configuring actions to modify packet fields
1. Enter system view. system-view
2. Enter policy node view. policy-based-route policy-name [ deny | permit ] node node-number
3. Configure actions.
Set an IP precedence. apply precedence { type | value }
By default, no IP precedence is specified.
Configuring actions to direct packet forwarding
1. Enter system view. system-view
2. Enter policy node view. policy-based-route policy-name [ deny | permit ] node node-number
3. Configure actions.
Set VPN instances.
apply access-vpn vpn-instance vpn-instance-name &<1-n>
By default, no VPN instances are specified.
You can specify a maximum of n VPN instances for a node. The matching packets are forwarded according to the forwarding table of the first available VPN instance.
After configuring this command, you cannot configure the redirect public enable command in the VPN instance view. For more information about the redirect public enable command, see MPLS L3VPN in MPLS Configuration Guide .
474
Enable VPN remark action to mark the matching packets as belonging to the VPN instance to which they are forwarded based on the apply access-vpn vpn-instance command. apply remark-vpn
By default, VPN remark action is not configured.
Set next hops. apply next-hop [ vpn-instance vpn-instance-name ] { ip-address
[ direct ] [ track track-entry-number ] }&<1-2>
By default, no next hops are specified.
On a node, you can specify a maximum of two next hops for backup in one command line or by executing this command multiple times.
Set output interfaces. apply output-interface { interface-type interface-number [ track track-entry-number ] }
By default, no output interfaces are specified.
As a best practice, do not specify the interface of a VXLAN tunnel automatically created by
EVPN for this command.
Set default next hops. apply default-next-hop [ vpn-instance vpn-instance-name | inbound-vpn ] { ip-address [ direct ] [ track track-entry-number ] }&<1-2>
By default, no default next hops are specified.
On a node, you can specify a maximum of two default next hops for backup in one command line or by executing this command multiple times.
Set default output interfaces. apply default-output-interface { interface-type interface-number
[ track track-entry-number ]
By default, no default output interfaces are specified.
As a best practice, do not specify the interface of a VXLAN tunnel automatically created by
EVPN for this command.
Collecting policy node statistics
1. Enter system view. system-view
2. Enter policy node view. policy-based-route policy-name [ deny | permit ] node node-number
3. Count successful matches and matching bytes on the policy node. apply statistics
By default, match counting is disabled on a policy node.
After configuring this command, you cannot specify the share-mode keyword when applying the policy to an interface for interface PBR.
475
Specifying a policy for PBR
Specifying a policy for local PBR
About this task
Perform this task to specify a policy for local PBR to guide the forwarding of locally generated packets.
Restrictions and guidelines
You can specify only one policy for local PBR and must make sure the specified policy already exists.
Before you apply a new policy, you must first remove the current policy.
Local PBR might affect local services such as ping and Telnet. When you use local PBR, make sure you fully understand its impact on local services of the device.
Procedure
1. Enter system view. system-view
2. Specify a policy for local PBR. ip local policy-based-route policy-name
By default, local PBR is not enabled.
Specifying a policy for interface PBR
About this task
Perform this task to apply a policy to an interface to guide the forwarding of packets received on the interface.
Restrictions and guidelines
You can apply only one policy to an interface and must make sure the specified policy already exists.
Before you can apply a new interface PBR policy to an interface, you must first remove the current policy from the interface.
You can apply a policy to multiple interfaces.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify a policy for interface PBR. ip policy-based-route policy-name [ share-mode ]
By default, no interface policy is applied to an interface.
You cannot specify the share-mode keyword for the command if you have configured the apply statistics command for the policy.
476
Enabling the PBR logging feature
About this task
The PBR logging feature helps the administrator locate and fix faults. The feature logs PBR events and sends the logs to the information center. The information center processes the logs according to output rules. For more information about the information center, see System Management
Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enable the PBR logging feature. ip policy-based-route-log enable
By default, the PBR logging feature is disabled.
Verifying and maintaining PBR
Verifying PBR policy configuration
To display PBR policy information, execute the following command in any view: display ip policy-based-route [ policy policy-name ]
Displaying PBR configuration and statistics
Perform display tasks in any view.
•
Display PBR configuration. display ip policy-based-route setup
•
Display local PBR configuration and statistics. display ip policy-based-route local [ slot slot-number ]
•
Display interface PBR configuration and statistics. display ip policy-based-route interface interface-type interface-number [ slot slot-number ]
Clearing PBR statistics
To clear PBR statistics, execute the following command in user view: reset ip policy-based-route statistics [ policy policy-name ]
PBR configuration examples
Example: Configuring packet type-based local PBR
Network configuration
As shown in Figure 102 , Device B and Device C do not have a route to reach each other.
Configure PBR on Device A to forward all TCP packets to the next hop 1.1.2.2 (Device B).
477
Figure 102 Network diagram
Device B
HGE1/0/1
1.1.2.1/24
HGE1/0/1
1.1.2.2/24
Device A
HGE1/0/2
1.1.3.1/24
HGE1/0/2
1.1.3.2/24
Device C
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure Device A:
# Configure the IP addresses of HundredGigE 1/0/1 and HundredGigE 1/0/2.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ip address 1.1.2.1 24
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ip address 1.1.3.1 24
[DeviceA-HundredGigE1/0/2] quit
# Configure ACL 3101 to match TCP packets.
[DeviceA] acl advanced 3101
[DeviceA-acl-ipv4-adv-3101] rule permit tcp
[DeviceA-acl-ipv4-adv-3101] quit
# Configure Node 5 for the policy aaa to forward TCP packets to next hop 1.1.2.2.
[DeviceA] policy-based-route aaa permit node 5
[DeviceA-pbr-aaa-5] if-match acl 3101
[DeviceA-pbr-aaa-5] apply next-hop 1.1.2.2
[DeviceA-pbr-aaa-5] quit
# Configure local PBR by applying the policy aaa to Device A.
[DeviceA] ip local policy-based-route aaa
2. On Device B, configure the IP address of HundredGigE 1/0/1.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ip address 1.1.2.2 24
3. On Device C, configure the IP address of HundredGigE 1/0/2.
<DeviceC> system-view
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ip address 1.1.3.2 24
Verifying the configuration
1. Perform telnet operations to verify that local PBR on Device A operates as configured to forward the matching TCP packets to the next hop 1.1.2.2 (Device B), as follows:
# Verify that you can telnet to Device B from Device A successfully. (Details not shown.)
# Verify that you cannot telnet to Device C from Device A. (Details not shown.)
478
2. Verify that Device A forwards packets other than TCP packets through HundredGigE 1/0/2. For example, verify that you can ping Device C from Device A. (Details not shown.)
Example: Configuring packet type-based interface PBR
Network configuration
As shown in Figure 103 , Device B and Device C do not have a route to reach each other.
Configure PBR on Device A to forward all TCP packets received on HundredGigE 1/0/1 to the next hop 1.1.2.2 (Device B).
Figure 103 Network diagram
Device B Device C
HGE1/0/2
1.1.2.2/24
HGE1/0/3
1.1.3.2/24
HGE1/0/2
1.1.2.1/24
HGE1/0/3
1.1.3.1/24
Device A
HGE1/0/1
10.110.0.10/24
Subnet
10.110.0.0/24
Host A
10.110.0.20/24
Gateway: 10.110.0.10
Procedure
Host B
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Make sure Device B and Device C can reach Host A. (Details not shown.)
2. Configure Device A:
# Configure the IP addresses of HundredGigE 1/0/2 and HundredGigE 1/0/3.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ip address 1.1.2.1 24
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface hundredgige 1/0/3
[DeviceA-HundredGigE1/0/3] ip address 1.1.3.1 24
[DeviceA-HundredGigE1/0/3] quit
# Configure ACL 3101 to match TCP packets.
[DeviceA] acl advanced 3101
479
[DeviceA-acl-ipv4-adv-3101] rule permit tcp
[DeviceA-acl-ipv4-adv-3101] quit
# Configure Node 5 for the policy aaa to forward TCP packets to next hop 1.1.2.2.
[DeviceA] policy-based-route aaa permit node 5
[DeviceA-pbr-aaa-5] if-match acl 3101
[DeviceA-pbr-aaa-5] apply next-hop 1.1.2.2
[DeviceA-pbr-aaa-5] quit
# Configure interface PBR by applying the policy aaa to HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ip address 10.110.0.10 24
[DeviceA-HundredGigE1/0/1] ip policy-based-route aaa
[DeviceA-HundredGigE1/0/1] quit
Verifying the configuration
1. Perform telnet operations to verify that interface PBR on Device A operates as configured to forward the matching TCP packets to the next hop 1.1.2.2 (Device B), as follows:
# Verify that you can telnet to Device B from Host A successfully. (Details not shown.)
# Verify that you cannot telnet to Device C from Host A. (Details not shown.)
2. Verify that Device A forwards packets other than TCP packets through HundredGigE 1/0/3. For example, verify that you can ping Device C from Host A. (Details not shown.)
Example: Configuring source-IP-based interface PBR
Network configuration
As shown in Figure 104 , Device B and Device C do not have a route to reach each other.
Configure interface PBR to guide the forwarding of packets received on HundredGigE 1/0/1 of
Device A as follows:
•
Set the next hop of packets sourced from 192.168.10.2 to 4.1.1.2/24.
•
Set the next hop of other packets to 5.1.1.2/24.
480
Figure 104 Network diagram
Device B Device C
HGE1/0/2
4.1.1.2/24
HGE1/0/3
5.1.1.2/24
HGE1/0/2
4.1.1.1/24
Device A
HGE1/0/3
5.1.1.1/24
HGE1/0/1
192.168.10.1/24
Subnet
192.168.10.0/24
Host A
192.168.10.2/24
Gateway: 192.168.10.1
Procedure
Host B
192.168.10.3/24
Gateway: 192.168.10.1
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Make sure Device B can reach Host A and Host B, and Device C can reach Host A and Host B.
(Details not shown.)
2. Configure Device A:
# Configure the IP addresses of HundredGigE 1/0/2 and HundredGigE 1/0/3.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ip address 4.1.1.1 24
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface hundredgige 1/0/3
[DeviceA-HundredGigE1/0/3] ip address 5.1.1.1 24
[DeviceA-HundredGigE1/0/3] quit
# Configure ACL 2000 to match packets sourced from 192.168.10.2.
[DeviceA] acl basic 2000
[DeviceA-acl-ipv4-basic-2000] rule 10 permit source 192.168.10.2 0
[DeviceA-acl-ipv4-basic-2000] quit
# Configure Node 0 for the policy aaa to forward packets sourced from 192.168.10.2 to next hop 4.1.1.2. Configure Node 1 for the policy aaa to forward other packets to next hop 5.1.1.2.
[DeviceA] policy-based-route aaa permit node 0
[DeviceA-pbr-aaa-0] if-match acl 2000
[DeviceA-pbr-aaa-0] apply next-hop 4.1.1.2
[DeviceA-pbr-aaa-0] quit
[DeviceA] policy-based-route aaa permit node 1
481
[DeviceA-pbr-aaa-1] apply next-hop 5.1.1.2
[DeviceA-pbr-aaa-1] quit
# Configure interface PBR by applying the policy aaa to HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ip address 192.168.10.1 24
[DeviceA-HundredGigE1/0/1] ip policy-based-route aaa
[DeviceA-HundredGigE1/0/1] quit
Verifying the configuration
1. Verify that interface PBR on Device A operates as configured to forward packets sourced from
192.168.10.2 to the next hop 4.1.1.2 and packets sourced from 192.168.10.3 to the next hop
5.1.1.2:
# Configure IP address 192.168.10.3/24 for Host B, and specify its gateway address as
192.168.10.1. (Details not shown.)
# Verify that you can ping Device B from Host A. (Details not shown.)
# Verify that you can ping Device C from Host B. (Details not shown.)
# Verify that you cannot ping Device B from Host B. (Details not shown.)
# Verify that you cannot ping Device C from Host A. (Details not shown.)
482
Configuring IPv6 static routing
About IPv6 static routing
Static routes are manually configured and cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually. IPv6 static routing works well in a simple IPv6 network.
Configuring an IPv6 static route
1. Enter system view. system-view
2. Configure an IPv6 static route.
Public network: ipv6 route-static ipv6-address prefix-length { interface-type interface-number [ next-hop-address ] | next-hop-address | vpn-instance d-vpn-instance-name next-hop-address } [ permanent ]
[ preference preference ] [ tag tag-value ] [ description text ]
VPN: ipv6 route-static vpn-instance s-vpn-instance-name ipv6-address prefix-length { interface-type interface-number [ next-hop-address ] | next-hop-address [ public ] | vpn-instance d-vpn-instance-name next-hop-address } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]
By default, no IPv6 static route is configured.
3. (Optional.) Set the default preference for IPv6 static routes. ipv6 route-static default-preference default-preference
The default setting is 60.
Deleting IPv6 static routes
About this task
To delete an IPv6 static route, use the undo ipv6 route-static command. To delete all IPv6 static routes including the default route, use the delete ipv6 static-routes all command.
Procedure
1. Enter system view. system-view
2. Delete all IPv6 static routes, including the default route. delete ipv6 [ vpn-instance vpn-instance-name ] static-routes all
CAUTION:
This command might interrupt network communication and cause packet forwarding failure.
Before executing the command, make sure you fully understand the potential impact on the network.
483
Configuring BFD for IPv6 static routes
About BFD for IPv6 static routes
BFD provides a general purpose, standard, and medium- and protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of the bidirectional forwarding paths between two routers for protocols, such as routing protocols and MPLS. BFD for IPv6 static routes tests the reachability of the next hop for each IPv6 static route. If a next hop is unreachable,
BFD deletes the associated IPv6 static route.
For more information about BFD, see High Availability Configuration Guide .
Restrictions and guidelines for BFD
Enabling BFD for a flapping route could worsen the situation.
Configuring BFD control packet mode
About this task
This mode uses BFD control packets to detect the status of a link bidirectionally at a millisecond level.
BFD control packet mode can be applied to IPv6 static routes with a direct next hop or with an indirect next hop.
Restrictions and guidelines for BFD control packet mode
If you configure BFD control packet mode at the local end, you must also configure this mode at the peer end.
Do not use BFD for a static route if the output interface of the static route is a tunnel interface.
Configuring BFD control packet mode for an IPv6 static route (direct next hop)
1. Enter system view. system-view
2. Configure BFD control packet mode for an IPv6 static route. ipv6 route-static [ vpn-instance s-vpn-instance-name ] ipv6-address prefix-length interface-type interface-number next-hop-address bfd control-packet [ bfd-source ipv6-address ] [ preference preference ]
[ tag tag-value ] [ description text ]
By default, BFD control packet mode for an IPv6 static route is not configured.
Configuring BFD control packet mode for an IPv6 static route (indirect next hop)
1. Enter system view. system-view
2. Configure BFD control packet mode for an IPv6 static route. ipv6 route-static [ vpn-instance s-vpn-instance-name ] ipv6-address prefix-length [ vpn-instance d-vpn-instance-name ] { next-hop-address bfd control-packet bfd-source ipv6-address } [ preference preference ]
[ tag tag-value ] [ description text ]
By default, BFD control packet mode for an IPv6 static route is not configured.
484
Configuring BFD echo packet mode
About this task
With BFD echo packet mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability.
Restrictions and guidelines
You do not need to configure BFD echo packet mode at the peer end.
Do not use BFD for a static route with the output interface in spoofing state.
Do not use BFD for a static route if the output interface of the static route is a tunnel interface.
Procedure
1. Enter system view. system-view
2. Configure the source address of echo packets.
bfd echo-source-ipv6 ipv6-address
By default, the source address of echo packets is not configured.
The source address of echo packets must be a global unicast address.
For more information about this command, see High Availability Command Reference .
3. Configure BFD echo packet mode for an IPv6 static route. ipv6 route-static [ vpn-instance s-vpn-instance-name ] ipv6-address prefix-length interface-type interface-number next-hop-address bfd echo-packet [ bfd-source ipv6-address ] [ preference preference ] [ tag tag-value ] [ description text ]
By default, BFD echo packet mode for an IPv6 static route is not configured.
The next hop IPv6 address must be a global unicast address.
Verifying and maintaining IPv6 static routing
Perform display tasks in any view.
•
Display IPv6 static route information. display ipv6 routing-table protocol static [ inactive | verbose ]
For more information about this command, see basic IP routing commands in Layer 3—IP
Routing Command Reference .
•
Display IPv6 static route next hop information. display ipv6 route-static nib [ nib-id ] [ verbose ]
•
Display IPv6 static routing table information. display ipv6 route-static routing-table [ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length ]
IPv6 static routing configuration examples
Example: Configuring basic IPv6 static route
Network configuration
As shown in Figure 105 , configure IPv6 static routes so that hosts can reach each other.
485
Figure 105 Network diagram
Host B
2::2/64
HGE1/0/3
2::1/64
HGE1/0/2
4::1/64
HGE1/0/1
4::2/64
Device B
HGE1/0/2
5::2/64
HGE1/0/2
5::1/64
Host A
1::2/64
Prerequisites
HGE1/0/1
1::1/64
Device A
HGE1/0/1
Device C
3::1/64
Host C
3::2/64
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 static routes:
# Configure the default IPv6 route on Device A.
<DeviceA> system-view
[DeviceA] ipv6 route-static :: 0 4::2
# Configure two IPv6 static routes on Device B.
<DeviceB> system-view
[DeviceB] ipv6 route-static 1:: 64 4::1
[DeviceB] ipv6 route-static 3:: 64 5::1
# Configure the default IPv6 route on Device C.
<DeviceC> system-view
[DeviceC] ipv6 route-static :: 0 5::2
3. Configure the IPv6 addresses for all hosts and configure the default gateway of Host A, Host B, and Host C as 1::1, 2::1, and 3::1.
Verifying the configuration
# Display the IPv6 static route information on Device A.
[DeviceA] display ipv6 routing-table protocol static
Summary Count : 1
Static Routing table Status : <Active>
Summary Count : 1
Destination: :: Protocol : Static
NextHop : 4::2 Preference: 60
Interface : HGE1/0/2 Cost : 0
486
Static Routing table Status : <Inactive>
Summary Count : 0
# Display the IPv6 static route information on Device B.
[DeviceB] display ipv6 routing-table protocol static
Summary Count : 2
Static Routing table Status : <Active>
Summary Count : 2
Destination: 1::/64 Protocol : Static
NextHop : 4::1 Preference: 60
Interface : HGE1/0/1 Cost : 0
Destination: 3::/64 Protocol : Static
NextHop : 5::1 Preference: 60
Interface : HGE1/0/2 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
# Use the ping command to test reachability.
[DeviceA] ping ipv6 3::1
Ping6(56 data bytes) 4::1 --> 3::1, press CTRL_C to break
56 bytes from 3::1, icmp_seq=0 hlim=62 time=0.700 ms
56 bytes from 3::1, icmp_seq=1 hlim=62 time=0.351 ms
56 bytes from 3::1, icmp_seq=2 hlim=62 time=0.338 ms
56 bytes from 3::1, icmp_seq=3 hlim=62 time=0.373 ms
56 bytes from 3::1, icmp_seq=4 hlim=62 time=0.316 ms
--- Ping6 statistics for 3::1 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 0.316/0.416/0.700/0.143 ms
Example: Configuring BFD for IPv6 static routes (direct next hop)
Network configuration
•
Configure an IPv6 static route to subnet 120::/64 on Device A.
•
Configure an IPv6 static route to subnet 121::/64 on Device B.
•
Enable BFD for both routes.
•
Configure an IPv6 static route to subnet 120::/64 and an IPv6 static route to subnet 121::/64 on
Device C.
When the link between Device A and Device B through the Layer 2 switch fails, BFD can detect the failure immediately and inform Device A and Device B to communicate through Device C.
487
Figure 106 Network diagram
121::/64
Device A
HGE1/0/1
L2 Switch
HGE1/0/1
Device B
HGE1/0/2
BFD
HGE1/0/1 HGE1/0/2
HGE1/0/2
120::/64
Device C
Table 25 Interface and IP address assignment
Device
Device A
Device A
Device B
Device B
Device C
Device C
Prerequisites
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
IPv6 address
12::1/64
10::102/64
12::2/64
13::1/64
10::100/64
13::2/64
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 static routes and BFD:
# Configure IPv6 static routes on Device A, and enable BFD control packet mode for the IPv6 static route that traverses HundredGigE 1/0/1.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 9
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] ipv6 route-static 120:: 64 hundredgige 1/0/1 12::2 bfd control-packet
[DeviceA] ipv6 route-static 120:: 64 10::100 preference 65
[DeviceA] quit
# Configure IPv6 static routes on Device B, and enable BFD control packet mode for the IPv6 static route that traverses the Layer 2 switch.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
488
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 9
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] ipv6 route-static 121:: 64 hundredgige 1/0/1 12::1 bfd control-packet
[DeviceB] ipv6 route-static 121:: 64 13::2 preference 65
[DeviceB] quit
# Configure IPv6 static routes on Device C.
<DeviceC> system-view
[DeviceC] ipv6 route-static 120:: 64 13::1
[DeviceC] ipv6 route-static 121:: 64 10::102
Verifying the configuration
# Display BFD sessions on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 session working in control packet mode:
Local Discr: 513 Remote Discr: 33
Source IP: 12::1
Destination IP: 12::2
Session State: Up Interface: HGE1/0/1
Hold Time: 2012ms
The output shows that the BFD session has been created.
# Display IPv6 static routes on Device A.
<DeviceA> display ipv6 routing-table protocol static
Summary Count : 1
Static Routing table Status : <Active>
Summary Count : 1
Destination: 120::/64 Protocol : Static
NextHop : 12::2 Preference: 60
Interface : HGE1/0/1 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. The link over HundredGigE 1/0/1 fails.
# Display IPv6 static routes on Device A.
<DeviceA> display ipv6 routing-table protocol static
Summary Count : 1
Static Routing table Status : <Active>
Summary Count : 1
489
Destination: 120::/64 Protocol : Static
NextHop : 10::100 Preference: 65
Interface : HGE1/0/2 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
Example: Configuring BFD for IPv6 static routes (indirect next hop)
Network configuration
•
Device A has a route to interface Loopback 1 (2::9/128) on Device B, and the output interface is
HundredGigE 1/0/1.
•
Device B has a route to interface Loopback 1 (1::9/128) on Device A, and the output interface is
HundredGigE 1/0/1.
•
Device D has a route to 1::9/128, and the output interface is HundredGigE 1/0/1. It also has a route to 2::9/128, and the output interface is HundredGigE 1/0/2.
Configure the following:
•
Configure an IPv6 static route to subnet 120::/64 on Device A.
•
Configure an IPv6 static route to subnet 121::/64 on Device B.
•
Enable BFD for both routes.
•
Configure an IPv6 static route to subnet 120::/64 and an IPv6 static route to subnet 121::/64 on both Device C and Device D.
When the link between Device A and Device B through Device D fails, BFD can detect the failure immediately and Device A and Device B can communicate through Device C.
Figure 107 Network diagram
121::/64 Loop1
1::9/128
Loop1
2::9/128
Device D
HGE1/0/1
HGE1/0/1
Device A
HGE
1/0
/2
BFD
HGE1/0/1
HGE1/0/2
1/
0/
2
Device B
HGE
HGE1/0/1 HGE1/0/2
120::/64
Device B
Table 26 Interface and IP address assignment
Device
Device A
Device A
Device A
Interface
HGE1/0/1
HGE1/0/2
Loop1
IPv6 address
12::1/64
10::102/64
1::9/128
490
Device
Device B
Device B
Device B
Device C
Device C
Device D
Device D
Prerequisites
Interface
HGE1/0/1
HGE1/0/2
Loop1
HGE1/0/1
HGE1/0/2
HGE1/0/1
HGE1/0/2
IPv6 address
11::2/64
13::1/64
2::9/128
10::100/64
13::2/64
12::2/64
11::1/64
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 static routes and BFD:
# Configure IPv6 static routes on Device A and enable BFD control packet mode for the IPv6 static route that traverses Device D.
<DeviceA> system-view
[DeviceA] bfd multi-hop min-transmit-interval 500
[DeviceA] bfd multi-hop min-receive-interval 500
[DeviceA] bfd multi-hop detect-multiplier 9
[DeviceA] ipv6 route-static 120:: 64 2::9 bfd control-packet bfd-source 1::9
[DeviceA] ipv6 route-static 120:: 64 10::100 preference 65
[DeviceA] ipv6 route-static 2::9 128 12::2
[DeviceA] quit
# Configure IPv6 static routes on Device B and enable BFD control packet mode for the IPv6 static route that traverses Device D.
<DeviceB> system-view
[DeviceB] bfd multi-hop min-transmit-interval 500
[DeviceB] bfd multi-hop min-receive-interval 500
[DeviceB] bfd multi-hop detect-multiplier 9
[DeviceB] ipv6 route-static 121:: 64 1::9 bfd control-packet bfd-source 2::9
[DeviceB] ipv6 route-static 121:: 64 13::2 preference 65
[DeviceB] ipv6 route-static 1::9 128 11::1
[DeviceB] quit
# Configure IPv6 static routes on Device C.
<DeviceC> system-view
[DeviceC] ipv6 route-static 120:: 64 13::1
[DeviceC] ipv6 route-static 121:: 64 10::102
# Configure IPv6 static routes on Device D.
<DeviceD> system-view
[DeviceD] ipv6 route-static 120:: 64 11::2
[DeviceD] ipv6 route-static 121:: 64 12::1
491
[DeviceD] ipv6 route-static 2::9 128 11::2
[DeviceD] ipv6 route-static 1::9 128 12::1
Verifying the configuration
# Display BFD sessions on Device A.
<DeviceA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 session working in control packet mode:
Local Discr: 513 Remote Discr: 33
Source IP: 1::9
Destination IP: 2::9
Session State: Up Interface: N/A
Hold Time: 2012ms
The output shows that the BFD session has been created.
# Display IPv6 static routes on Device A.
<DeviceA> display ipv6 routing-table protocol static
Summary Count : 1
Static Routing table Status : <Active>
Summary Count : 1
Destination: 120::/64 Protocol : Static
NextHop : 2::9 Preference: 60
Interface : HGE1/0/1 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. The link over HundredGigE 1/0/1 fails.
# Display IPv6 static routes on Device A.
<DeviceA> display ipv6 routing-table protocol static
Summary Count : 1
Static Routing table Status : <Active>
Summary Count : 1
Destination: 120::/64 Protocol : Static
NextHop : 10::100 Preference: 65
Interface : HGE1/0/2 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
492
Configuring an IPv6 default route
A default IPv6 route is used to forward packets that match no entry in the routing table.
A default IPv6 route can be configured in either of the following ways:
•
The network administrator can configure a default route with a destination prefix of ::/0 . For
more information, see " Configuring IPv6 static routing ."
•
Some dynamic routing protocols can generate a default IPv6 route. For example, an upstream router running OSPFv3 can generate a default IPv6 route and advertise it to other routers.
These routers install the default IPv6 route with the next hop being the upstream router. For more information, see the respective chapters on those routing protocols in this configuration guide.
493
Configuring RIPng
About RIPng
RIP next generation (RIPng), as an extension of RIP-2 for support of IPv6, is a distance vector routing protocol. It employs UDP to exchange route information through port 521. Most RIP concepts are applicable to RIPng.
RIPng routing metrics
RIPng uses a hop count to measure the distance to a destination. The hop count is the metric or cost.
The hop count from a router to a directly connected network is 0. The hop count between two directly connected routers is 1. When the hop count is greater than or equal to 16, the destination network or host is unreachable.
RIPng route entries
RIPng stores route entries in a database. Each route entry contains the following elements:
•
Destination address —IPv6 address of a destination host or a network.
•
Next hop address —IPv6 address of the next hop.
•
Egress interface —Egress interface of the route.
•
Metric —Cost from the local router to the destination.
•
Route time —Time elapsed since the most recent update. The time is reset to 0 every time the route entry is updated.
•
Route tag
—Used for route control. For more information, see " Configuring routing policies ."
RIPng packets and advertisement
RIPng multicasts request and response packets to exchange routing information. It uses FF02::9 as the destination address and link-local address FE80::/10 as the source address. RIPng exchanges routing information as follows:
1. When RIPng starts or needs to update some route entries, it sends a multicast request packet to neighbors.
2. When a RIPng neighbor receives the request packet, it sends back a response packet that contains the local routing table. RIPng can also advertise route updates in response packets periodically or advertise a triggered update caused by a route change.
3. After RIPng receives the response, it checks the validity of the response before adding routes to its routing table, including the following details:
Whether the source IPv6 address is the link-local address.
Whether the port number is correct.
4. A response packet that fails the check is discarded.
Protocols and standards
•
RFC 2080, RIPng for IPv6
•
RFC 2081, RIPng Protocol Applicability Statement
494
RIPng tasks at a glance
To configure RIPng, perform the following tasks:
1.
2.
(Optional.) Configuring RIPng route control
Configuring an additional routing metric
Configuring RIPng route summarization
Configuring received/redistributed route filtering
Setting a preference for RIPng
Configuring RIPng route redistribution
3.
(Optional.) Tuning and optimizing the RIPng network
Configuring split horizon and poison reverse
Setting the maximum number of ECMP routes
Configuring the RIPng packet sending rate
Setting the interval for sending triggered updates
4. (Optional.) Enhancing RIPng availability
(Optional.) Enhancing RIPng security
Configuring zero field check for RIPng packets
Configuring basic RIPng
1. Enter system view. system-view
2. Enable RIPng and enter its view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
By default, RIPng is disabled.
3. Return to system view. quit
4. Enter interface view. interface interface-type interface-number
5. Enable RIPng on the interface.
ripng process-id enable
By default, RIPng is disabled on the interface.
If RIPng is not enabled on an interface, the interface does not send or receive any RIPng route.
495
Configuring RIPng route control
Configuring an additional routing metric
About this task
An additional routing metric (hop count) can be added to the metric of an inbound or outbound RIPng route.
•
An outbound additional metric is added to the metric of a sent route, and it does not change the route's metric in the routing table.
•
An inbound additional metric is added to the metric of a received route before the route is added into the routing table, and the route's metric is changed.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify an inbound additional routing metric.
ripng metricin value
The default additional metric of an inbound route is 0.
4. Specify an outbound additional routing metric. ripng metricout value
The default additional metric of an outbound route is 1.
Configuring RIPng route summarization
About this task
RIPng route summarization is interface-based. RIPng advertises a summary route based on the longest match.
RIPng route summarization improves network scalability, reduces routing table size, and increases routing table lookup efficiency.
RIPng advertises a summary route with the smallest metric of all the specific routes.
For example, RIPng has two specific routes to be advertised through an interface: 1:11:11::24 with a metric of a 2 and 1:11:12::34 with a metric of 3. Configure route summarization on the interface, so
RIPng advertises a single route 11::0/16 with a metric of 2.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Advertise a summary IPv6 prefix.
ripng summary-address ipv6-address prefix-length
By default, no summary IPv6 prefix is configured on the interface.
496
Advertising a default route
About this task
You can configure RIPng to advertise a default route with the specified cost to its neighbors.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Configure RIPng to advertise a default route. ripng default-route { only | originate } [ cost cost-value |
route-policy route-policy-name ] *
By default, RIPng does not advertise a default route.
This command advertises a default route on the current interface regardless of whether the default route exists in the local IPv6 routing table.
Configuring received/redistributed route filtering
About this task
Perform this task to filter received or redistributed routes by using an IPv6 ACL or IPv6 prefix list. You can also configure RIPng to filter routes redistributed from other routing protocols and routes from a specified neighbor.
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure a filter policy to filter received routes. filter-policy { ipv6-acl-number | prefix-list prefix-list-name } import
By default, RIPng does not filter received routes.
4. Configure a filter policy to filter redistributed routes. filter-policy { ipv6-acl-number | prefix-list prefix-list-name } export [ protocol [ process-id ] ]
By default, RIPng does not filter redistributed routes.
Setting a preference for RIPng
About this task
Routing protocols each have a preference. When they find routes to the same destination, the route found by the routing protocol with the highest preference is selected as the optimal route. You can manually set a preference for RIPng. The smaller the value, the higher the preference.
Procedure
1. Enter system view. system-view
497
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set a preference for RIPng. preference { preference | route-policy route-policy-name } *
By default, the preference of RIPng is 100.
Configuring RIPng route redistribution
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure route redistribution. import-route protocol [ as-number | process-id ] [ allow-ibgp ]
[ allow-direct | cost cost-value | route-policy route-policy-name ] *
By default, RIPng does not redistribute routes.
4. (Optional.) Set a default routing metric for redistributed routes.
default cost cost-value
The default metric of redistributed routes is 0.
Tuning and optimizing the RIPng network
Setting RIPng timers
About this task
You can adjust RIPng timers to optimize the performance of the RIPng network.
Restrictions and guidelines
When you adjust RIPng timers, consider the network performance, and perform unified configurations on routers running RIPng to avoid unnecessary network traffic or route oscillation.
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set RIPng timers. timers { garbage-collect garbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value } *
The default settings are as follows:
The update timer is 30 seconds.
The timeout timer is 180 seconds.
The suppress timer is 120 seconds.
The garbage-collect timer is 120 seconds.
498
Configuring split horizon and poison reverse
Restrictions and guidelines for split horizon and poison reverse
When you configure split horizon and poison reverse, following these restrictions and guidelines:
•
If both split horizon and poison reverse are configured, only the poison reverse feature takes effect.
•
Split horizon disables RIPng from sending routes through the interface where the routes were learned to prevent routing loops between neighbors. As a best practice, enable split horizon to prevent routing loops in normal cases.
•
Poison reverse enables a route learned from an interface to be advertised through the interface.
However, the metric of the route is set to 16, which means the route is unreachable.
Configuring split horizon
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable split horizon. ripng split-horizon
By default, split horizon is enabled.
Configuring poison reverse
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable poison reverse. ripng poison-reverse
By default, poison reverse is disabled.
Setting the maximum number of ECMP routes
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the maximum number of ECMP routes. maximum load-balancing number
By default, the maximum number of RIPng ECMP routes equals the maximum number of
ECMP routes, which is configurable by using the max-ecmp-num command.
Configuring the RIPng packet sending rate
About this task
Perform this task to specify the interval for sending RIPng packets and the maximum number of
RIPng packets that can be sent at each interval. This feature can avoid excessive RIPng packets from affecting system performance and consuming too much bandwidth.
499
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configuring the RIPng packet sending rate.
Execute the following commands in sequence to configure the RIPng packet sending rate in
RIPng view: ripng [ process-id ] [ vpn-instance vpn-instance-name ]
output-delay time count count
By default, an interface that runs the RIPng process sends a maximum of three RIPng packets every 20 milliseconds.
Execute the following commands in sequence to configure the RIPng packet sending rate in interface view: interface interface-type interface-number ripng output-delay time count count
By default, an interface uses the RIPng packet sending rate of the RIPng process that it runs.
Setting the interval for sending triggered updates
About this task
Perform this task to avoid network overhead and reduce system resource consumption caused by frequent RIPng triggered updates.
You can use the timer triggered command to set the maximum interval, minimum interval, and incremental interval for sending RIPng triggered updates.
For a stable network, the minimum interval is used. If network changes become frequent, the triggered update sending interval is incremented by the incremental interval × 2 n-2
for each triggered update until the maximum interval is reached. The value n is the number of triggered update times.
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Set the interval for sending triggered updates.
timer triggered maximum-interval [ minimum-interval
[ incremental-interval ] ]
The default maximum interval is 5 seconds, the default minimum interval is 50 milliseconds, and the default incremental interval is 200 milliseconds.
Configuring RIPng GR
About this task
GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.
500
Two routers are required to complete a GR process. The following are router roles in a GR process:
•
GR restarter —Graceful restarting router. It must have GR capability.
•
GR helper —A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
After RIPng restarts on a router, the router must learn RIPng routes again and updates its FIB table, which causes network disconnections and route reconvergence.
With the GR feature, the restarting router (known as the GR restarter) can notify the event to its GR capable neighbors. GR capable neighbors (known as GR helpers) maintain their adjacencies with the router within a configurable GR interval. During this process, the FIB table of the router does not change. After the restart, the router contacts its neighbors to retrieve its FIB.
By default, a RIPng-enabled device acts as the GR helper. Perform this task on the GR restarter.
Restrictions and guidelines
You cannot enable RIPng NSR on a device that acts as GR restarter.
Procedure
1. Enter system view. system-view
2. Enable RIPng and enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable the GR capability for RIPng. graceful-restart
By default, RIPng GR is disabled.
4. (Optional.) Set the GR interval. graceful-restart interval interval
The default GR interval is 60 seconds.
Configuring RIPng NSR
About this task
Nonstop routing (NSR) backs up RIPng routing information from the active process to the standby process. After an active/standby switchover, NSR can complete route regeneration without tearing down adjacencies or impacting forwarding services.
NSR does not require the cooperation of neighboring devices to recover routing information, and it is typically used more often than GR.
Restrictions and guidelines
RIPng NSR enabled for a RIPng process takes effect only on that process. If multiple RIPng processes exist, enable RIPng NSR for each process as a best practice.
A device that has RIPng NSR enabled cannot act as GR restarter.
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable RIPng NSR. non-stop-routing
501
By default, RIPng NSR is disabled.
Configuring RIPng FRR
About RIPng FRR
A link or router failure on a path can cause packet loss and even routing loop until RIPng completes routing convergence based on the new network topology. FRR enables fast rerouting to minimize the impact of link or node failures.
Figure 108 Network diagram for RIPng FRR
Backup next hop: Router C
Router A Router B Next hop: Router D Router E
As shown in Figure 108 , configure FRR on Router B by using a routing policy to specify a backup
next hop. When the primary link fails, RIPng directs packets to the backup next hop. At the same time, RIPng calculates the shortest path based on the new network topology. Then, the device forwards packets over that path after network convergence.
Restrictions and guidelines for RIPng FRR
RIPng FRR is available only when the state of the primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down.
RIPng FRR is only effective for RIPng routes that are learned from directly connected neighbors.
Equal-cost routes do not support RIPng FRR.
Enabling RIPng FRR
1. Enter system view. system-view
2. Configure a routing policy.
You must specify a next hop by using the apply ipv6 fast-reroute backup-interface command in a routing policy and specify the routing policy for FRR.
For more information about routing policy configuration, see " Configuring routing policies ."
3. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
4. Enable RIPng FRR.
fast-reroute route-policy route-policy-name
By default, RIPng FRR is disabled.
502
Enabling BFD for RIPng FRR
About this task
By default, RIPng FRR does not use BFD to detect primary link failures. For quicker RIPng FRR, use
BFD single-hop echo detection on the primary link of redundant links to detect link failure.
Procedure
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ipv6 ipv6-address
By default, the source IP address of BFD echo packets is not configured.
As a best practice, do not configure the source IP address on the same network segment as any local interfaces.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD single-hop echo detection for RIPng FRR. ripng primary-path-detect bfd echo
By default, BFD single-hop echo detection is disabled for RIPng FRR.
Enhancing RIPng security
Configuring zero field check for RIPng packets
About this task
Some fields in the RIPng packet header must be zero. These fields are called zero fields. You can enable zero field check for incoming RIPng packets. If a zero field of a packet contains a non-zero value, RIPng does not process the packets. If you are certain that all packets are trustworthy, disable the zero field check to save CPU resources.
Procedure
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Enable the zero field check for incoming RIPng packets. checkzero
By default, zero field check for incoming RIPng packets is enabled.
Applying an IPsec profile
About this task
To protect routing information and prevent attacks, you can configure RIPng to authenticate protocol packets by using an IPsec profile.
503
An IPsec profile contains inbound and outbound security parameter indexes (SPIs). RIPng compares the inbound SPI defined in the IPsec profile with the outbound SPI in the received packets.
Two RIPng devices accept the packets from each other and establish a neighbor relationship only if the SPIs are the same and the relevant IPsec profiles match.
Restrictions and guidelines
You can apply an IPsec profile to a RIPng process or to an interface. If an interface and its process each have an IPsec profile, the IPsec profile applied to the interface takes effect.
Applying an IPsec profile to a process
1. Enter system view. system-view
2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
3. Apply an IPsec profile to the process. enable ipsec-profile profile-name
By default, no IPsec profile is applied.
Applying an IPsec profile to an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Apply an IPsec profile to the interface. ripng ipsec-profile profile-name
By default, no IPsec profile is applied.
Verifying and maintaining RIPng
Verifying RIPng configuration and running status
Verifying basic RIPng configuration and running status
Perform display tasks in any view.
•
Display configuration information for a RIPng process. display ripng [ process-id ]
•
Display routes in the RIPng database. display ripng process-id database [ ipv6-address prefix-length ]
•
Display interface information for a RIPng process. display ripng process-id interface [ interface-type interface-number ]
•
Display neighbor information for a RIPng process. display ripng process-id neighbor [ interface-type interface-number ]
•
Display the routing information for a RIPng process. display ripng process-id route [ ipv6-address prefix-length [ verbose ]
| peer ipv6-address | statistics ]
Verifying RIPng availability configuration
Perform display tasks in any view.
504
•
Display RIPng GR information. display ripng [ process-id ] graceful-restart
•
Display RIPng NSR information. display ripng [ process-id ] non-stop-routing
Clearing statistics for a RIPng process
To clear the statistics for a RIPng process, execute the following command in user view: reset ripng process-id statistics
Resetting a RIPng process
To reset a RIPng process, execute the following command in user view: reset ripng process-id process
RIPng configuration examples
Example: Configuring basic RIPng
Network configuration
As shown in Figure 109 , Device A, Device B, and Device C learn IPv6 routing information through
RIPng.
Configure Device B to filter the route (2::/64) learned from Device A. The route will not be added to the routing table of Device B, and Device B forwards only the route 4::/64 to Device A.
Figure 109 Network diagram
HGE1/0/3
4::1/64
HGE1/0/2
2::1/64
Device A
HGE1/0/1
1::1/64
HGE1/0/1
1::2/64
Procedure
Device B
HGE1/0/2
3::1/64
HGE1/0/1
3::2/64
Device C
HGE1/0/2
5::1/64
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for the interfaces. (Details not shown.)
2. Configure basic RIPng settings:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ripng 1
[DeviceA-ripng-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ripng 1 enable
505
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ripng 1 enable
[DeviceA-HundredGigE1/0/2] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ripng 1
[DeviceB-ripng-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ripng 1 enable
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ripng 1 enable
[DeviceB-HundredGigE1/0/2] quit
# Configure Device C.
<DeviceC> system-view
[DeviceC] ripng 1
[DeviceC-ripng-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ripng 1 enable
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ripng 1 enable
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] ripng 1 enable
[DeviceC-HundredGigE1/0/3] quit
# Display the RIPng routing table on Device B.
[DeviceB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D – Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::20F:E2FF:FE23:82F5 on HundredGigE1/0/1
Destination 2::/64,
via FE80::20F:E2FF:FE23:82F5, cost 1, tag 0, AOF, 6 secs
Peer FE80::20F:E2FF:FE00:100 on HundredGigE1/0/2
Destination 4::/64,
via FE80::20F:E2FF:FE00:100, cost 1, tag 0, AOF, 11 secs
Destination 5::/64,
via FE80::20F:E2FF:FE00:100, cost 1, tag 0, AOF, 11 secs
Local route
Destination 1::/64,
via ::, cost 0, tag 0, DOF
Destination 3::/64,
via ::, cost 0, tag 0, DOF
# Display the RIPng routing table on Device A.
[DeviceA] display ripng 1 route
506
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D – Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::200:2FF:FE64:8904 on HundredGigE1/0/1
Destination 3::/64,
via FE80::200:2FF:FE64:8904, cost 1, tag 0, AOF, 31 secs
Destination 4::/64,
via FE80::200:2FF:FE64:8904, cost 2, tag 0, AOF, 31 secs
Destination 5::/64,
via FE80::200:2FF:FE64:8904, cost 2, tag 0, AOF, 31 secs
Local route
Destination 2::/64,
via ::, cost 0, tag 0, DOF
Destination 1::/64,
via ::, cost 0, tag 0, DOF
3. Configure route filtering:
# Use IPv6 prefix lists on Device B to filter received and redistributed routes.
[DeviceB] ipv6 prefix-list aaa permit 4:: 64
[DeviceB] ipv6 prefix-list bbb deny 2:: 64
[DeviceB] ipv6 prefix-list bbb permit :: 0 less-equal 128
[DeviceB] ripng 1
[DeviceB-ripng-1] filter-policy prefix-list aaa export
[DeviceB-ripng-1] filter-policy prefix-list bbb import
[DeviceB-ripng-1] quit
# Display the RIPng routing tables on Device B and Device A.
[DeviceB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D – Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::1:1 on HundredGigE1/0/1
Peer FE80::3:1 on HundredGigE1/0/2
Destination 4::/64,
via FE80::2:2, cost 1, tag 0, AOF, 11 secs
Destination 5::/64,
via FE80::2:2, cost 1, tag 0, AOF, 11 secs
Local route
Destination 1::/64,
via ::, cost 0, tag 0, DOF
Destination 3::/64,
via ::, cost 0, tag 0, DOF
[DeviceA] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D – Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
507
Peer FE80::2:1 on HundredGigE1/0/1
Destination 4::/64,
via FE80::1:1, cost 2, tag 0, AOF, 2 secs
Local route
Destination 1::/64,
via ::, cost 0, tag 0, DOF
Destination 2::/64,
via ::, cost 0, tag 0, DOF
Example: Configuring RIPng route redistribution
Network configuration
As shown in Figure 110 , Device B communicates with Device A through RIPng 100 and with Device
C through RIPng 200.
Configure route redistribution on Device B, so the two RIPng processes can redistribute routes from each other.
Figure 110 Network diagram
RIPng 100
HGE1/0/1
2::1/64
Device A
HGE1/0/2
1::1/64
HGE1/0/2
1::2/64
Device B
HGE1/0/1
3::1/64
RIPng 200
HGE1/0/2
3::2/64
Device C
HGE1/0/1
4::1/64
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for the interfaces. (Details not shown.)
2. Configure basic RIPng settings:
# Enable RIPng 100 on Device A.
<DeviceA> system-view
[DeviceA] ripng 100
[DeviceA-ripng-100] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ripng 100 enable
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ripng 100 enable
# Enable RIPng 100 and RIPng 200 on Device B.
<DeviceB> system-view
[DeviceB] ripng 100
[DeviceB-ripng-100] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ripng 100 enable
[DeviceB-HundredGigE1/0/2] quit
508
[DeviceB] ripng 200
[DeviceB-ripng-200] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ripng 200 enable
# Enable RIPng 200 on Device C.
<DeviceC> system-view
[DeviceC] ripng 200
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ripng 200 enable
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ripng 200 enable
[DeviceC-HundredGigE1/0/2] quit
# Display the routing table on Device A.
[DeviceA] display ipv6 routing-table
Destinations : 7 Routes : 7
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 1::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 2::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 2::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
3. Configure RIPng route redistribution:
# Configure route redistribution between the two RIPng processes on Device B.
[DeviceB] ripng 100
509
[DeviceB-ripng-100] import-route ripng 200
[DeviceB-ripng-100] quit
[DeviceB] ripng 200
[DeviceB-ripng-200] import-route ripng 100
[DeviceB-ripng-200] quit
# Display the routing table on Device A.
[DeviceA] display ipv6 routing-table
Destinations : 8 Routes : 8
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 1::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 2::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 2::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : RIPng
NextHop : FE80::200:BFF:FE01:1C02 Preference: 100
Interface : HGE1/0/2 Cost : 1
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Example: Configuring RIPng GR
Network configuration
As shown in Figure 111 , Device A, Device B, and Device C learn IPv6 routing information through
RIPng.
510
Configure Device A as the GR restarter. Configure Device B and Device C as the GR helpers to synchronize their routing tables with Device A by using GR.
Figure 111 Network diagram
Router ID: 1.1.1.1
GR restarter
Device A
HGE1/0/1
2000::1/24
HGE1/0/1
2000::2/24
Device B
GR helper
Router ID: 2.2.2.2
Procedure
HGE1/0/1
2000::3/24
Device C
GR helper
Router ID: 3.3.3.3
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for the interfaces. (Details not shown.)
2. Configure RIPng on the devices to ensure the following: (Details not shown.)
Device A, Device B, and Device C can communicate with each other at Layer 3.
Dynamic route update can be implemented among them with RIPng.
3. Enable RIPng GR on Device A.
<DeviceA> system-view
[DeviceA] ripng 1
[DeviceA-ripng-1] graceful-restart
Verifying the configuration
# Restart RIPng or trigger an active/standby process switchover, and then display GR status on
Device A.
<DeviceA> display ripng 1 graceful-restart
RIPng process: 1
Graceful Restart capability : Enabled
Current GR state : Normal
Graceful Restart period : 60 seconds
Graceful Restart remaining time: 0 seconds
Example: Configuring RIPng NSR
Network configuration
As shown in Figure 112 , Device S, Device A, and Device B learn IPv6 routing information through
RIPng.
Enable RIPng NSR on Device S to ensure correct routing when an active/standby switchover occurs on Device S.
511
Figure 112 Network diagram
Loop 0
2002::2/128
Device A
HGE1/0/1
1200:1::1/64
HGE1/0/1
1200:1::2/64
Device S
HGE1/0/2
1400:1::2/64
HGE1/0/1
1400:1::1/64
Device B
Loop 0
4004::4/128
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for the interfaces. (Details not shown.)
2. Configure RIPng on the devices to ensure the following: (Details not shown.)
Device S, Device A, and Device B can communicate with each other at Layer 3.
Dynamic route update can be implemented among them with RIPng.
3. Enable RIPng NSR on Device S.
<DeviceS> system-view
[DeviceS] ripng 1
[DeviceS-ripng-1] non-stop-routing
[DeviceS-ripng-1] quit
Verifying the configuration
# Perform an active/standby switchover on Device S.
[DeviceS] placement reoptimize
Predicted changes to the placement
Program Current location New location
--------------------------------------------------------------------- staticroute 0/0 0/0 rib 0/0 0/0 staticroute6 0/0 0/0 rib6 0/0 0/0 isis 0/0 0/0 rip 0/0 0/0 ripng 0/0 1/0
Continue? [y/n]:y
Re-optimization of the placement start. You will be notified on completion
Re-optimization of the placement complete. Use 'display placement' to view the new placement
# During the switchover period, display RIPng neighbors on Device A to verify the neighbor relationship between Device A and Device S.
[DeviceA] display ripng 1 neighbor
Neighbor Address: FE80::AE45:5CE7:422E:2867
Interface : HundredGigE1/0/1
Version : RIPng version 1 Last update: 00h00m23s
Bad packets: 0 Bad routes : 0
# Display RIPng routes on Device A to verify if Device A has a route to the loopback interface on
Device B.
512
[DeviceA] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D - Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::AE45:5CE7:422E:2867 on HundredGigE1/0/1
Destination 1400:1::/64,
via FE80::AE45:5CE7:422E:2867, cost 1, tag 0, AOF, 1 secs
Destination 4004::4/128,
via FE80::AE45:5CE7:422E:2867, cost 2, tag 0, AOF, 1 secs
Local route
Destination 2002::2/128,
via ::, cost 0, tag 0, DOF
Destination 1200:1::/64,
via ::, cost 0, tag 0, DOF
# Display RIPng neighbors on Device B to verify the neighbor relationship between Device B and
Device S.
[DeviceB] display ripng 1 neighbor
Neighbor Address: FE80::20C:29FF:FECE:6277
Interface : HundredGigE1/0/1
Version : RIPng version 1 Last update: 00h00m18s
Bad packets: 0 Bad routes : 0
# Display RIPng routes on Device B to verify if Device B has a route to the loopback interface on
Device A.
[DeviceB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D - Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::20C:29FF:FECE:6277 on HundredGigE1/0/1
Destination 2002::2/128,
via FE80::20C:29FF:FECE:6277, cost 2, tag 0, AOF, 24 secs
Destination 1200:1::/64,
via FE80::20C:29FF:FECE:6277, cost 1, tag 0, AOF, 24 secs
Local route
Destination 4004::4/128,
via ::, cost 0, tag 0, DOF
Destination 1400:1::/64,
via ::, cost 0, tag 0, DOF
The output shows the following when an active/standby switchover occurs on Device S:
•
The neighbor relationships and routing information on Device A and Device B have not changed.
•
The traffic from Device A to Device B has not been impacted.
Example: Configuring RIPng FRR
Network configuration
As shown in Figure 113 , Device A, Device B, and Device C run RIPng. Configure RIPng FRR so that
when Link A becomes unidirectional, traffic can be switched to Link B immediately.
513
Figure 113 Network diagram
Device C
HGE
1/0
/1
HGE
1/0
/2
Link B
HGE
1/0
/1
Link A
Loop0
Device A
HGE1/0/2
Table 27 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Device A
Device A
Device B
Device B
Device B
Device C
Device C
Procedure
Interface
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
Loopback 0
HundredGigE 1/0/1
HundredGigE 1/0/2
IP address
1::1/64
2::1/64
10::1/128
3::1/64
2::2/64
20::1/128
1::2/64
3::2/64
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IPv6 addresses for the interfaces on the devices. (Details not shown.)
2. Configure RIPng on the devices to make sure Device A, Device B, and Device C can communicate with each other at the network layer. (Details not shown.)
3. Configure RIPng FRR:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ipv6 prefix-list abc index 10 permit 20::1 128
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceA-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 1::2
[DeviceA-route-policy-frr-10] quit
[DeviceA] ripng 1
[DeviceA-ripng-1] fast-reroute route-policy frr
[DeviceA-ripng-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ipv6 prefix-list abc index 10 permit 10::1 128
[DeviceB] route-policy frr permit node 10
514
[DeviceB-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceB-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige
1/0/1 backup-nexthop 3::2
[DeviceB-route-policy-frr-10] quit
[DeviceB] ripng 1
[DeviceB-ripng-1] fast-reroute route-policy frr
[DeviceB-ripng-1] quit
Verifying the configuration
# Display the route 20::1/128 on Device A to view the backup next hop information.
[DeviceA] display ipv6 routing-table 20::1 128 verbose
Summary count : 1
Destination: 20::1/128
Protocol: RIPng
Process ID: 1
SubProtID: 0x0 Age: 00h17m42s
Cost: 1 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Inactive Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x22000003 LastAs: 0
AttrID: 0xffffffff Neighbor: FE80::34CD:9FF:FE2F:D02
Flags: 0x41 OrigNextHop: FE80::34CD:9FF:FE2F:D02
Label: NULL RealNextHop: FE80::34CD:9FF:FE2F:D02
BkLabel: NULL BkNextHop: FE80::7685:45FF:FEAD:102
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display the route 10::1/128 on Device B to view the backup next hop information.
[DeviceB] display ipv6 routing-table 10::1 128 verbose
Summary count : 1
Destination: 10::1/128
Protocol: RIPng
Process ID: 1
SubProtID: 0x0 Age: 00h22m34s
Cost: 1 Preference: 100
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Inactive Adv
515
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x22000001 LastAs: 0
AttrID: 0xffffffff Neighbor: FE80::34CC:E8FF:FE5B:C02
Flags: 0x41 OrigNextHop: FE80::34CC:E8FF:FE5B:C02
Label: NULL RealNextHop: FE80::34CC:E8FF:FE5B:C02
BkLabel: NULL BkNextHop: FE80::7685:45FF:FEAD:102
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
516
Configuring OSPFv3
About OSPFv3
This chapter describes how to configure RFC 2740-compliant Open Shortest Path First version 3
(OSPFv3) for an IPv6 network.
Comparison of OSPFv3 with OSPFv2
OSPFv3 and OSPFv2 have the following in common:
•
32-bit router ID and area ID.
•
Hello, Database Description (DD), Link State Request (LSR), Link State Update (LSU), Link
State Acknowledgment (LSAck).
•
Mechanisms for finding neighbors and establishing adjacencies.
•
Mechanisms for advertising and aging LSAs.
OSPFv3 and OSPFv2 have the following differences:
•
OSPFv3 runs on a per-link basis. OSPFv2 runs on a per-IP-subnet basis.
•
OSPFv3 supports running multiple processes on an interface, but OSPFv2 does not support.
•
OSPFv3 identifies neighbors by router ID. OSPFv2 identifies neighbors by IP address.
For more information about OSPFv2, see " Configuring OSPF ."
OSPFv3 packets
OSPFv3 uses the following packet types:
•
Hello —Periodically sent to find and maintain neighbors, containing timer values, information about the DR, BDR, and known neighbors.
•
DD —Describes the digest of each LSA in the LSDB, exchanged between two routers for data synchronization.
•
LSR —Requests needed LSAs from the neighbor. After exchanging the DD packets, the two routers know which LSAs of the neighbor are missing from their LSDBs. They then send an
LSR packet to each other, requesting the missing LSAs. The LSA packet contains the digest of the missing LSAs.
•
LSU —Transmits the requested LSAs to the neighbor.
•
LSAck —Acknowledges received LSU packets.
OSPFv3 LSA types
OSPFv3 sends routing information in LSAs. The following LSAs are commonly used:
•
Router LSA —Type-1 LSA, originated by all routers. This LSA describes the collected states of the router's interfaces to an area, and is flooded throughout a single area only.
•
Network LSA —Type-2 LSA, originated for broadcast and NBMA networks by the DR. This LSA contains the list of routers connected to the network, and is flooded throughout a single area only.
•
Inter-Area-Prefix LSA —Type-3 LSA, originated by ABRs and flooded throughout the LSA's associated area. Each Inter-Area-Prefix LSA describes a route with IPv6 address prefix to a destination outside the area, yet still inside the AS.
517
•
Inter-Area-Router LSA —Type-4 LSA, originated by ABRs and flooded throughout the LSA's associated area. Each Inter-Area-Router LSA describes a route to ASBR.
•
AS External LSA —Type-5 LSA, originated by ASBRs, and flooded throughout the AS, except stub areas and Not-So-Stubby Areas (NSSAs). Each AS External LSA describes a route to another AS. A default route can be described by an AS External LSA.
•
NSSA LSA —Type-7 LSA, originated by ASBRs in NSSAs and flooded throughout a single
NSSA. NSSA LSAs describe routes to other ASs.
•
Link LSA —Type-8 LSA. A router originates a separate Link LSA for each attached link. Link
LSAs have link-local flooding scope. Each Link LSA describes the IPv6 address prefix of the link and Link-local address of the router.
•
Intra-Area-Prefix LSA —Type-9 LSA. Each Intra-Area-Prefix LSA contains IPv6 prefix information on a router, stub area, or transit area information, and has area flooding scope. It was introduced because Router LSAs and Network LSAs contain no address information.
•
Grace LSA —Type-11 LSA, generated by a GR restarter at reboot and transmitted on the local link. The GR restarter describes the cause and interval of the reboot in the Grace LSA to notify its neighbors that it performs a GR operation.
Protocols and standards
•
RFC 2328, OSPF Version 2
•
RFC 3101, OSPF Not-So-Stubby Area (NSSA) Option
•
RFC 4552, Authentication/Confidentiality for OSPFv3
•
RFC 5187, OSPFv3 Graceful Restart
•
RFC 5286, Basic Specification for IP Fast Reroute: Loop-Free Alternates
•
RFC 5329, Traffic Engineering Extensions to OSPF Version 3
•
RFC 5340, OSPF for IPv6
•
RFC 5523, OSPFv3-Based Layer 1 VPN Auto-Discovery
•
RFC 5643, Management Information Base for OSPFv3
•
RFC 6506, Supporting Authentication Trailer for OSPFv3
•
RFC 6565, OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol
•
RFC 6969, OSPFv3 Instance ID Registry Update
OSPFv3 tasks at a glance
To configure OSPFv3, perform the following tasks:
1.
2.
(Optional.) Configuring OSPFv3 area parameters
Configuring an OSPFv3 virtual link
Perform this task on an ABR to create a virtual link when connectivity cannot be maintained between a non-backbone area and the backbone, or within the backbone.
3.
(Optional.) Configuring OSPFv3 network types
Setting the broadcast network type for an OSPFv3 interface
Setting the NBMA network type for an OSPFv3 interface
Setting the P2MP network type for an OSPFv3 interface
518
Setting the P2P network type for an OSPFv3 interface
4.
(Optional.) Configuring OSPFv3 route control
Configuring OSPFv3 inter-area route summarization
Configuring OSPFv3 received route filtering
Configuring Inter-Area-Prefix LSA filtering
Setting an OSPFv3 cost for an interface
Setting the maximum number of OSPFv3 ECMP routes
Setting a preference for OSPFv3
Configuring OSPFv3 route redistribution
5.
(Optional.) Setting OSPFv3 timers
Setting LSA transmission delay
Setting SPF calculation interval
Setting the LSA generation interval
6.
(Optional.) Setting a DR priority for an interface
7.
(Optional.) Configuring OSPFv3 packet parameters
Ignoring MTU check for DD packets
Setting the DSCP value for outgoing OSPFv3 packets
Disabling interfaces from receiving and sending OSPFv3 packets
8.
(Optional.) Accelerating OSPFv3 convergence speed
Configuring prefix suppression
9.
(Optional.) Configuring a stub router
10. (Optional.) Enhancing OSPFv3 availability
11. (Optional.) Enhancing OSPFv3 security
Configuring OSPFv3 authentication
Applying an IPsec profile for authenticating OSPFv3 packets
12.
Configuring OSPFv3 logging and SNMP notifications
Enabling logging for neighbor state changes
Setting the maximum number of OSPFv3 logs
Configuring OSPFv3 network management
Enabling OSPFv3
About this task
To enable an OSPFv3 process on a router:
1. Enable the OSPFv3 process globally.
2. Assign the OSPFv3 process a router ID.
519
3. Enable the OSPFv3 process on related interfaces.
An OSPFv3 process ID has only local significance. Process 1 on a router can exchange packets with process 2 on another router.
OSPFv3 requires you to manually specify a router ID for each router in an AS. Make sure all assigned router IDs in the AS are unique.
Restrictions and guideline
If a router runs multiple OSPFv3 processes, you must specify a unique router ID for each process.
Procedure
1. Enter system view. system-view
2. Enable an OSPFv3 process and enter its view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
By default, no OSPFv3 processes are enabled.
3. Specify a router ID. router-id router-id
By default, no router ID is configured.
4. Enter interface view. interface interface-type interface-number
5. Enable an OSPFv3 process on the interface.
ospfv3 process-id area area-id [ instance instance-id ]
By default, no OSPFv3 processes are enabled on an interface.
Configuring OSPFv3 area parameters
About OSPFv3 areas
OSPFv3 has the same stub area, NSSA area, and virtual link features as OSPFv2.
After you split an OSPFv3 AS into multiple areas, the LSA number is reduced and OSPFv3 applications are extended. To further reduce the size of routing tables and the number of LSAs, configure the non-backbone areas at an AS edge as stub areas.
A stub area cannot import external routes, but an NSSA area can import external routes into the
OSPFv3 routing domain while retaining other stub area characteristics.
Non-backbone areas exchange routing information through the backbone area, so the backbone and non-backbone areas (including the backbone itself) must be fully meshed. If no connectivity can be achieved, configure virtual links.
Configuring a stub area
Restrictions and guidelines
To configure a stub area, you must perform this task on all routers attached to the area.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view.
520
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view.
area area-id
4. Configure the area as a stub area. stub [ default-route-advertise-always | no-summary ] *
By default, no area is configured as a stub area.
The no-summary keyword is only available on the ABR of a stub area. If you specify the no-summary keyword, the ABR only advertises a default route in an Inter-Area-Prefix LSA into the stub area.
5. (Optional.) Set a cost for the default route advertised to the stub area. default-cost cost value
By default, the cost for the default route advertised to the stub area is 1.
Configuring an NSSA area
Restrictions and guidelines
To configure an NSSA area, you must perform this task on all routers attached to the area.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Configure the area as an NSSA area. nssa [ default-route-advertise [ cost cost-value | nssa-only |
route-policy route-policy-name | tag tag | type type ] * | no-import-route | no-summary | [ translate-always | translate-never ] | suppress-fa | translator-stability-interval value ] *
By default, no area is configured as an NSSA area.
To configure a totally NSSA area, execute the nssa no-summary command on the ABR. The
ABR of a totally NSSA area does not advertise inter-area routes into the area.
5. (Optional.) Set a cost for the default route advertised to the NSSA area. default-cost cost-value
By default, the cost for the default route advertised to the NSSA area is 1.
This command takes effect only on the ABR/ASBR of an NSSA or totally NSSA area.
Configuring an OSPFv3 virtual link
About this task
You can configure a virtual link to maintain connectivity between a non-backbone area and the backbone, or in the backbone itself.
Restrictions and guidelines
Both ends of a virtual link are ABRs that must be configured with the vlink-peer command.
521
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view.
area area-id
4. Configure a virtual link.
vlink-peer router-id [ dead seconds | hello seconds | instance instance-id | ipsec-profile profile-name | keychain keychain-name |
retransmit seconds | trans-delay seconds ] *
Configuring OSPFv3 network types
Restrictions and guidelines for OSPFv3 network type configuration
Based on the link layer protocol, OSPFv3 classifies networks into different types, including broadcast,
NBMA, P2MP, and P2P.
•
Configure the network type as NBMA if routers that do not support multicast addresses exist in the broadcast network.
•
Configure the network type as P2P if only two routers run OSPFv3 in the network.
Setting the broadcast network type for an OSPFv3 interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the network type to broadcast for the OSPFv3 interface. ospfv3 network-type broadcast [ instance instance-id ]
By default, the network type of an interface is broadcast.
Setting the NBMA network type for an OSPFv3 interface
Restrictions and guidelines
For NBMA interfaces, you must specify the link-local IP addresses and DR priorities for their neighbors because these interfaces cannot find neighbors by broadcasting hello packets.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the network type to NBMA for the OSPFv3 interface.
522
ospfv3 network-type nbma [ instance instance-id ]
By default, the network type of an OSPFv3 interface is broadcast.
4. (Optional.) Set the router priority for the interface ospfv3 dr-priority priority
By default, an interface has a router priority of 1.
An interface's router priority determines its privilege in DR/BDR selection.
5. Specify an NBMA neighbor. ospfv3 peer ipv6-address [ cost cost value | dr-priority priority ]
[ instance instance-id ]
By default, no link-local address is specified for the neighbor interface.
Setting the P2MP network type for an OSPFv3 interface
Restrictions and guidelines
For P2MP interfaces (only when in unicast mode), you must specify the link-local IP addresses of their neighbors because these interfaces cannot find neighbors by broadcasting hello packets.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the network type to P2MP for the OSPFv3 interface. ospfv3 network-type p2mp [ unicast ] [ instance instance-id ]
By default, the network type of an interface is broadcast.
4. Specify a P2MP unicast neighbor. ospfv3 peer ipv6-address [ cost cost value | dr-priority priority ]
[ instance instance-id ]
By default, no link-local address is specified for the neighbor interface.
Setting the P2P network type for an OSPFv3 interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the network type to P2P for the OSPFv3 interface. ospfv3 network-type p2p [ instance instance-id ]
By default, the network type of an OSPFv3 interface is broadcast.
523
Configuring OSPFv3 route control
Configuring OSPFv3 inter-area route summarization
About this task
If contiguous network segments exist in an area, you can summarize them into one network segment on the ABR. The ABR will advertise only the summary route. Any LSA on the specified network segment will not be advertised, reducing the LSDB size in other areas.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view.
area area-id
4. Configure route summarization on the ABR. abr-summary ipv6-address prefix-length [ not-advertise ] [ cost cost value ]
By default, route summarization is not configured on an ABR.
Configuring redistributed route summarization
About this task
Perform this task to enable an ASBR to summarize external routes within the specified address range into a single route.
An ASBR can summarize routes in the following LSAs:
•
Type-5 LSAs.
•
Type-7 LSAs in an NSSA area.
•
Type-5 LSAs translated from Type-7 LSAs in an NSSA area if the ASBR (also an ABR) is a translator. If the ASBR is not a translator, it cannot summarize routes in Type-5 LSAs translated from Type-7 LSAs.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure route summarization on an ASBR. asbr-summary ipv6-address prefix-length [ cost cost-value | not-advertise | nssa-only | tag tag ] *
By default, route summarization is not configured on an ASBR.
524
Configuring OSPFv3 received route filtering
About this task
This task allows you to filter routes calculated by using received LSAs.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure OSPFv3 to filter routes calculated by using received LSAs. filter-policy { ipv6-acl-number [ gateway prefix-list-name ] | prefix-list prefix-list-name [ gateway prefix-list-name ] | gateway prefix-list-name | route-policy route-policy-name } import
By default, OSPFv3 accepts all routes calculated by using received LSAs.
This command can only filter routes computed by OSPFv3. Only routes not filtered out can be added into the local routing table.
Configuring Inter-Area-Prefix LSA filtering
Restrictions and guidelines
The filter command takes effect only on ABRs.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Configure OSPFv3 to filter Inter-Area-Prefix LSAs. filter { ipv6-acl-number | prefix-list prefix-list-name | route-policy route-policy-name } { export | import }
By default, OSPFv3 accepts all Inter-Area-Prefix LSAs.
Setting an OSPFv3 cost for an interface
About this task
You can set an OSPFv3 cost for an interface with one of the following methods:
•
Set the cost value in interface view.
•
Set a bandwidth reference value for the interface, and OSPFv3 computes the cost automatically based on the bandwidth reference value by using the following formula:
Interface OSPFv3 cost = Bandwidth reference value (100 Mbps) / Interface bandwidth (Mbps)
If the calculated cost is greater than 65535, the value of 65535 is used.
If the calculated cost is smaller than 1, the value of 1 is used.
•
If no cost is set for an interface, OSPFv3 automatically computes the cost for the interface.
525
Setting a cost in interface view
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set an OSPFv3 cost for the interface.
ospfv3 cost cost value [ instance instance-id ]
By default, the OSPFv3 cost is 1 for a VLAN interface, is 0 for a loopback interface. The
OSPFv3 cost is automatically computed according to the interface bandwidth for other interfaces.
Setting a bandwidth reference value
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set a bandwidth reference value.
bandwidth-reference value
The default bandwidth reference value is 100 Mbps.
Setting the maximum number of OSPFv3 ECMP routes
About this task
OSPFv3 might find multiple equal-cost routes to the same destination, which can be used to share the traffic load. This task allows you to set the maximum number of ECMP routes.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set the maximum number of ECMP routes. maximum load-balancing number
By default, the maximum number of ECMP routes supported by OSPFv3 equals the maximum number of ECMP routes supported by the system.
Setting a preference for OSPFv3
About this task
A router can run multiple routing protocols. The system assigns a priority for each protocol. When these routing protocols find the same route, the route found by the protocol with the highest priority is selected.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view.
526
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set a preference for OSPFv3. preference [ ase ] { preference | route-policy route-policy-name } *
By default, the preference of OSPFv3 internal routes is 10, and the preference of OSPFv3 external routes is 150.
Configuring OSPFv3 route redistribution
Restrictions and guidelines
Because OSPFv3 is a link state routing protocol, it cannot directly filter LSAs to be advertised.
OSPFv3 filters only redistributed routes. Only routes that are not filtered out can be advertised in
LSAs.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure route redistribution. import-route bgp4+ [ as-number ] [ allow-ibgp ] [ cost cost-value | inherit-cost ] | nssa-only | route-policy route-policy-name | tag tag | type type ] * import-route { direct | static } [ cost cost-value | inherit-cost ] | nssa-only | route-policy route-policy-name | tag tag | type type ] * import-route { isisv6 | ospfv3 | ripng } [ process-id | all-processes ]
[ allow-direct | [ cost cost-value | inherit-cost ] | nssa-only | route-policy route-policy-name | tag tag | type type ] *
By default, OSPFv3 does not redistribute routes.
The import-route bgp4+ command redistributes only EBGP routes. The import-route bgp4+ allow-ibgp command redistributes both EBGP and IBGP routes, which might cause routing loops. There, use the import-route bgp4+ allow-ibgp command with caution.
4. (Optional.) Configure OSPFv3 to filter redistributed routes. filter-policy { ipv6-acl-number | prefix-list prefix-list-name }
export [ bgp4+ | direct | { isisv6 | ospfv3 | ripng } [ process-id ] | static ]
By default, OSPFv3 accepts all redistributed routes.
This command filters only routes redistributed by the import-route command. If no routes are redistributed by the import-route command, this command does not take effect.
5. Set a tag for redistributed routes.
default tag tag
By default, the tag of redistributed routes is 1.
Configuring default route redistribution
About this task
The import-route command cannot redistribute a default external route. To redistribute a default route, perform this task.
527
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Redistribute a default route. default-route-advertise [ [ always | permit-calculate-other ] | cost cost-value | route-policy route-policy-name | tag tag | type type ] *
By default, no default route is redistributed.
4. Set a tag for redistributed routes.
default tag tag
By default, the tag of redistributed routes is 1.
Setting OSPFv3 timers
Setting OSPFv3 packet timers
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Set the hello interval. ospfv3 timer hello seconds [ instance instance-id ]
The default hello interval on P2P and broadcast interfaces is 10 seconds. The default hello interval on P2MP and NBMA interfaces is 30 seconds.
4. Set the dead interval. ospfv3 timer dead seconds [ instance instance-id ]
The default dead interval on P2P and broadcast interfaces is 40 seconds. The default dead interval on P2MP and NBMA interfaces is 120 seconds.
The dead interval set on neighboring interfaces cannot be too short. If the interval is too short, a neighbor is easily down.
5. Set the poll interval. ospfv3 timer poll seconds [ instance instance-id ]
By default, the poll interval is 120 seconds.
6. Set the LSA retransmission interval.
ospfv3 timer retransmit interval [ instance instance-id ]
The default LSA retransmission interval is 5 seconds.
The LSA retransmission interval cannot be too short. If the interval is too short, unnecessary retransmissions will occur.
528
Setting LSA transmission delay
About this task
Each LSA in the LSDB has an age that increases by 1 every second, but the age does not change during transmission. Therefore, it is necessary to add a transmission delay into the age time, especially for low-speed links.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Set the LSA transmission delay. ospfv3 trans-delay seconds [ instance instance-id ]
By default, the LSA transmission delay is 1 second.
Setting SPF calculation interval
About this task
LSDB changes result in SPF calculations. When the topology changes frequently, a large amount of network and router resources are occupied by SPF calculation. You can adjust the SPF calculation interval to reduce the impact.
For a stable network, the minimum interval is used. If network changes become frequent, the SPF calculation interval increases by the incremental interval × 2 n-2
for each calculation until the maximum interval is reached. The value n is the number of calculation times.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set the SPF calculation interval.
spf-schedule-interval maximum-interval [ minimum-interval
[ incremental-interval ] ]
By default, the maximum interval is 5 seconds, the minimum interval is 50 milliseconds, and the incremental interval is 200 milliseconds.
Setting the LSA generation interval
About this task
You can adjust the LSA generation interval to protect network resources and routers from being over consumed by frequent network changes.
For a stable network, the minimum interval is used. If network changes become frequent, the LSA generation interval increases by the incremental interval × 2 n-2
for each generation until the maximum interval is reached. The value n is the number of generation times.
Procedure
1. Enter system view.
529
system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set the LSA generation interval. lsa-generation-interval maximum-interval [ minimum-interval
[ incremental-interval ] ]
By default, the maximum interval is 5 seconds, the minimum interval is 0 milliseconds, and the incremental interval is 0 milliseconds.
Setting the LSU transmit rate
About this task
Sending large numbers of LSU packets affects router performance and consumes a large amount of network bandwidth. You can configure the router to send LSU packets at an interval and to limit the maximum number of LSU packets sent out of an OSPFv3 interface at each interval.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set the LSU transmit rate. transmit-pacing interval interval count count
By default, an OSPFv3 interface sends a maximum of three LSU packets every 20 milliseconds.
Setting a DR priority for an interface
About this task
The router priority is used for DR election. Interfaces having the priority 0 cannot become a DR or
BDR.
Procedure
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Set a router priority. ospfv3 dr-priority priority [ instance instance-id ]
The default router priority is 1.
530
Configuring OSPFv3 packet parameters
Ignoring MTU check for DD packets
About this task
When LSAs are few in DD packets, it is unnecessary to check the MTU in DD packets to improve efficiency.
Restrictions and guidelines
A neighbor relationship can be established only if the interface's MTU is the same as that of the peer.
Procedure
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Ignore MTU check for DD packets. ospfv3 mtu-ignore [ instance instance-id ]
By default, OSPFv3 does not ignore MTU check for DD packets.
Setting the DSCP value for outgoing OSPFv3 packets
About this task
The DSCP value specifies the precedence of outgoing packets.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance instance-name ] *
3. Set the DSCP value for outgoing OSPFv3 packets. dscp dscp-value
By default, the DSCP value for outgoing OSPFv3 packets is 48.
Disabling interfaces from receiving and sending OSPFv3 packets
About this task
After an OSPFv3 interface is set to silent , direct routes of the interface can still be advertised in
Intra-Area-Prefix LSAs through other interfaces, but other OSPFv3 packets cannot be advertised.
No neighboring relationship can be established on the interface. This feature can enhance the adaptability of OSPFv3 networking.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view.
531
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Disable interfaces from receiving and sending OSPFv3 packets. silent-interface { interface-type interface-number | all }
By default, the interfaces can receive and send OSPFv3 packets.
This command disables only the interfaces that run the current process. However, multiple
OSPFv3 processes can disable the same interface from receiving and sending OSPFv3 packets.
Accelerating OSPFv3 convergence speed
Configuring OSPFv3 ISPF
About this task
Incremental SPF (ISPF) allows the system to recalculate nodes affected by topology changes rather than the entire OSPFv3 shortest path tree. OSPFv3 ISPF saves CPU resources caused by SPF calculations and accelerates the convergence speed.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable OSPFv3 ISPF. ispf enable
By default, OSPFv3 ISPF is enabled.
Configuring prefix suppression
About this task
By default, an OSPFv3 interface advertises all of its prefixes in LSAs. To speed up OSPFv3 convergence, you can suppress interfaces from advertising all of their prefixes. This feature helps improve network security by preventing IP routing to the suppressed networks.
When prefix suppression is enabled:
•
OSPFv3 does not advertise the prefixes of suppressed interfaces in Type-8 LSAs.
•
On broadcast and NBMA networks, the DR does not advertise the prefixes of suppressed interfaces in Type-9 LSAs that reference Type-2 LSAs.
•
On P2P and P2MP networks, OSPFv3 does not advertise the prefixes of suppressed interfaces in Type-9 LSAs that reference Type-1 LSAs.
Restrictions and guidelines for prefix suppression
As a best practice, configure prefix suppression on all OSPFv3 routers if you want to use prefix suppression.
Configuring prefix suppression for an OSPFv3 process
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
532
3. Enable prefix suppression for the OSPFv3 process. prefix-suppression
By default, prefix suppression is disabled for an OSPFv3 process.
Enabling prefix suppression for an OSPFv3 process does not suppress the prefixes of loopback interfaces and passive interfaces.
Configuring prefix suppression for an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable prefix suppression for the interface. ospfv3 prefix-suppression [ disable ] [ instance instance-id ]
By default, prefix suppression is disabled for an interface.
Configuring PIC
About this task
Prefix Independent Convergence (PIC) enables the device to converge without the dependence on the number of prefixes. The convergence time does not increase as the number of prefixes in the routing table increases.
Restrictions and guidelines for OSPFv3 PIC
When both OSPFv3 PIC and OSPFv3 FRR are configured, OSPFv3 FRR takes effect.
OSPFv3 PIC applies only to inter-area routes and external routes.
Enabling PIC
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance instance-name ] *
3. Enable PIC for OSPFv3. pic [ additional-path-always ]
By default, PIC is enabled for OSPFv3.
Configuring BFD OSPFv3 PIC (control packet mode)
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for OSPFv3 PIC. ospfv3 primary-path-detect bfd ctrl [ instance instance-id ]
By default, BFD control packet mode is disabled for OSPFv3 PIC.
To speed up OSPFv3 convergence, enable BFD control packet mode for OSPFv3 PIC to detect the primary link failures. This mode requires BFD configuration on both OSPFv3 routers on the link.
533
Configuring BFD for OSPFv3 PIC (echo packet mode)
1. Enter system view. system-view
2. Configure the source IP address of BFD echo packets. bfd echo-source-ip ip-address
By default, the source IP address of BFD echo packets is not configured.
The source IP address cannot be on the same network segment as any local interface's IP address.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for OSPFv3 PIC. ospfv3 primary-path-detect bfd echo [ instance instance-id ]
By default, BFD echo packet mode is disabled for OSPFv3 PIC.
To speed up OSPFv3 convergence, enable BFD single-hop echo packet mode for OSPFv3 PIC to detect the primary link failures. This mode requires BFD configuration on one OSPFv3 router on the link.
Configuring a stub router
About this task
A stub router is used for traffic control. It reports its status as a stub router to neighboring OSPFv3 routers. The neighboring routers can have a route to the stub router, but they do not use the stub router to forward data.
Use either of the following methods to configure a router as a stub router:
•
Clear the R-bit of the Option field in Type-1 LSAs. When the R-bit is clear, the OSPFv3 router can participate in OSPFv3 topology distribution without forwarding traffic.
•
Use the OSPFv3 max-metric router LSA feature. This feature enables OSPFv3 to advertise its locally generated Type-1 LSAs with a maximum cost of 65535. Neighbors do not send packets to the stub router as long as they have a route with a smaller cost.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure the router as a stub router.
Configure the router as a stub router and clear the R-bit of the Option field in Type-1 LSAs.
stub-router r-bit [ include-stub | on-startup { seconds | wait-for-bgp [ seconds ] } ] *
Configure the router as a stub router and advertise the locally generated Type-1 LSAs with the maximum cost of 65535.
stub-router max-metric [ external-lsa [ max-metric-value ] | summary-lsa [ max-metric-value ] | include-stub | on-startup
{ seconds | wait-for-bgp [ seconds ] } ] *
By default, the router is not configured as a stub router.
A stub router is not related to a stub area.
534
Configuring OSPFv3 GR
About OSPFv3 GR
GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.
Two routers are required to complete a GR process. The following are router roles in a GR process:
•
GR restarter —Graceful restarting router. It must be Graceful Restart capable.
•
GR helper —The neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
To prevent service interruption after a master/backup switchover, a GR restarter running OSPFv3 must perform the following tasks:
•
Keep the GR restarter forwarding entries stable during reboot.
•
Establish all adjacencies and obtain complete topology information after reboot.
After the active/standby switchover, the GR restarter sends a Grace LSA to tell its neighbors that it performs a GR. Upon receiving the Grace LSA, the neighbors with the GR helper capability enter the helper mode (and are called GR helpers). Then, the GR restarter retrieves its adjacencies and LSDB with the help of the GR helpers.
Restrictions and guidelines for OSPFv3 GR
You cannot enable OSPFv3 NSR on a device that acts as GR restarter.
Configuring GR restarter
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable the GR capability. graceful-restart enable [ global | planned-only ] *
By default, OSPFv3 GR restarter capability is disabled.
4. (Optional.) Set the GR interval.
graceful-restart interval interval
By default, the GR interval is 120 seconds.
Configuring GR helper
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable the GR helper capability. graceful-restart helper enable [ planned-only ]
535
By default, the GR helper capability is enabled.
4. Enable strict LSA checking. graceful-restart helper strict-lsa-checking
By default, strict LSA checking is disabled.
Triggering OSPFv3 GR
About this task
OSPFv3 GR is triggered by an active/standby switchover or when this task is performed.
Procedure
To trigger OSPFv3 GR, execute the reset ospfv3 [ process id ] process graceful-restart command in user view.
Configuring OSPFv3 NSR
About this task
Nonstop routing (NSR) backs up OSPFv3 link state information from the active process to the standby process. After an active/standby switchover, NSR can complete link state recovery and route regeneration without tearing down adjacencies or impacting forwarding services.
NSR does not require the cooperation of neighboring devices to recover routing information, and it is typically used more often than GR.
Restrictions and guidelines
A device that has OSPFv3 NSR enabled cannot act as GR restarter.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable OSPFv3 NSR. non-stop-routing
By default, OSPFv3 NSR is disabled.
This command takes effect only for the current process. As a best practice, enable OSPFv3
NSR for each process if multiple OSPFv3 processes exist.
Configuring BFD for OSPFv3
About this task
Bidirectional forwarding detection (BFD) provides a mechanism to quickly detect the connectivity of links between OSPFv3 neighbors, improving the convergence speed of OSPFv3. For more information about BFD, see High Availability Configuration Guide .
After discovering neighbors by sending hello packets, OSPFv3 notifies BFD of the neighbor addresses, and BFD uses these addresses to establish sessions. Before a BFD session is established, it is in the down state. In this state, BFD control packets are sent at an interval of no less than 1 second to reduce BFD control packet traffic. After the BFD session is established, BFD control packets are sent at the negotiated interval, thereby implementing fast fault detection.
536
To configure BFD for OSPFv3, you need to configure OSPFv3 first.
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Specify a router ID. router-id router-id
4. Quit the OSPFv3 view. quit
5. Enter interface view. interface interface-type interface-number
6. Enable an OSPFv3 process on the interface.
ospfv3 process-id area area-id [ instance instance-id ]
7. Enable BFD on the interface. ospfv3 bfd enable [ instance instance-id ]
By default, BFD is disabled on the OSPFv3 interface.
Configuring OSPFv3 FRR
About OSPFv3 FRR
A primary link failure can cause packet loss and even a routing loop until OSPFv3 completes routing convergence based on the new network topology. OSPFv3 FRR enables fast rerouting to minimize the failover time.
Figure 114 Network diagram for OSPFv3 FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
As shown in Figure 114 , configure FRR on Router B. OSPFv3 FRR automatically calculates a
backup next hop or specifies a backup next hop by using a routing policy. When the primary link fails,
OSPFv3 directs packets to the backup next hop. At the same time, OSPFv3 calculates the shortest path based on the new network topology. It forwards packets over the path after network convergence.
You can configure OSPFv3 FRR to calculate a backup next hop by using the loop free alternate (LFA) algorithm, or specify a backup next hop by using a routing policy.
537
Configuring OSPFv3 FRR to use the LFA algorithm to calculate a backup next hop
Restrictions and guidelines
Do not use the fast-reroute lfa command together with the vlink-peer command.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Disable LFA on an interface. ospfv3 fast-reroute lfa-backup exclude
By default, the interface on which LFA is enabled can be selected as a backup interface.
4. Return to system view. quit
5. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
6. Enable OSPFv3 FRR to use the LFA algorithm to calculate a backup next hop. fast-reroute lfa [ abr-only ]
By default, OSPFv3 FRR is disabled.
If abr-only is specified, the route to the ABR is selected as the backup path.
Configuring OSPFv3 FRR to use a backup next hop in a routing policy
About this task
Before you perform this task, use the apply ipv6 fast-reroute backup-interface command to specify a backup next hop in the routing policy to be used. For more information about the apply ipv6 fast-reroute backup-interface command and routing policy
configuration, see " Configuring routing policies ."
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. (Optional.) Disable LFA on an interface. ospfv3 fast-reroute lfa-backup exclude
By default, the interface is enabled with LFA and it can be selected as a backup interface.
4. Return to system view. quit
5. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
6. Configure OSPFv3 FRR to use a backup next hop in a routing policy.
538
fast-reroute route-policy route-policy-name
By default, OSPFv3 FRR is disabled.
Configuring BFD control packet mode for OSPFv3 FRR
About this task
By default, OSPFv3 FRR does not use BFD to detect primary link failures. To speed up OSPFv3 convergence, enable BFD control packet mode for OSPFv3 FRR to detect primary link failures. This mode requires BFD configuration on both OSPFv3 routers on the link.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Enable BFD control packet mode for OSPFv3 FRR. ospfv3 primary-path-detect bfd ctrl [ instance instance-id ]
By default, BFD control packet mode is disabled for OSPFv3 FRR.
Configuring BFD echo packet mode for OSPFv3 FRR
About this task
By default, OSPFv3 FRR does not use BFD to detect primary link failures. To speed up OSPFv3 convergence, enable BFD echo packet mode for OSPFv3 FRR to detect primary link failures. This mode requires BFD configuration on one OSPFv3 router on the link.
Procedure
1. Enter system view. system-view
2. Configure the source IPv6 address of BFD echo packets. bfd echo-source-ipv6 ipv6-address
By default, the source IPv6 address of BFD echo packets is not configured.
The source IPv6 address cannot be on the same network segment as any local interface's IP address.
For more information about this command, see High Availability Command Reference .
3. Enter interface view. interface interface-type interface-number
4. Enable BFD echo packet mode for OSPFv3 FRR. ospfv3 primary-path-detect bfd echo [ instance instance-id ]
By default, BFD echo packet mode is disabled for OSPFv3 FRR.
Configuring OSPFv3 authentication
About OSPFv3 authentication
OSPFv3 uses keychain authentication to prevent routing information from being leaked and routers from being attacked.
539
OSPFv3 adds the Authentication Trailer option into outgoing packets, and uses the authentication information in the option to authenticate incoming packets. Only packets that pass the authentication can be received. If a packet fails the authentication, the OSPFv3 neighbor relationship cannot be established.
Restrictions and guidelines
The authentication mode specified for an OSPFv3 interface has a higher priority than the mode specified for an OSPFv3 area.
Configuring OSPFv3 area authentication
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Specify an authentication mode for the area. authentication-mode keychain keychain-name
By default, no authentication is performed for the area.
For more information about keychains, see Security Configuration Guide .
Configuring OSPFv3 interface authentication
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Specify an authentication mode for the interface. ospfv3 authentication-mode keychain keychain-name [ instance instance-id ]
By default, no authentication is performed for the interface.
For more information about keychains, see Security Configuration Guide .
Applying an IPsec profile for authenticating
OSPFv3 packets
About this task
To protect routing information and prevent attacks, OSPFv3 can authenticate protocol packets by using an IPsec profile. For more information about IPsec profiles, see Security Configuration Guide .
Outbound OSPFv3 packets carry the Security Parameter Index (SPI) defined in the relevant IPsec profile. A device compares the SPI carried in a received packet with the configured IPsec profile. If they match, the device accepts the packet. Otherwise, the device discards the packet and will not establish a neighbor relationship with the sending device.
540
Restrictions and guidelines for applying an IPsec profile
You can configure an IPsec profile for an area, an interface, a virtual link, or a sham link.
•
To implement area-based IPsec protection, configure the same IPsec profile on the routers in the target area.
•
To implement interface-based IPsec protection, configure the same IPsec profile on the interfaces between two neighboring routers.
•
To implement virtual link-based IPsec protection, configure the same IPsec profile on the two routers connected over the virtual link.
•
To implement sham link-based IPsec protection, configure the same IPsec profile on the two routers connected over the sham link. For more information about sham links, see MPLS
Configuration Guide .
•
If an interface and its area each have an IPsec profile configured, the interface uses its own
IPsec profile.
•
If a virtual link and area 0 each have an IPsec profile configured, the virtual link uses its own
IPsec profile.
•
If a sham link and its area have an IPsec profile configured, the sham link uses its own IPsec profile.
Applying an IPsec profile to an area
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Apply an IPsec profile to the area. enable ipsec-profile profile-name
By default, no IPsec profile is applied.
Applying an IPsec profile to an interface
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Apply an IPsec profile to the interface. ospfv3 ipsec-profile profile-name [ instance instance-id ]
By default, no IPsec profile is applied.
Applying an IPsec profile to a virtual link
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Apply an IPsec profile to a virtual link.
541
vlink-peer router-id [ dead seconds | hello seconds | instance instance-id | keychain keychain-name | retransmit seconds |
trans-delay seconds ] *
By default, no IPsec profile is applied.
Applying an IPsec profile to a sham link
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view. area area-id
4. Apply an IPsec profile to a sham link.
sham-link source-ipv6-address destination-ipv6-address [ cost cost-value | dead dead-interval | hello hello-interval | instance instance-id | ipsec-profile profile-name | keychain keychain-name |
retransmit retrans-interval | trans-delay delay ] *
By default, no IPsec profile is applied.
Configuring OSPFv3 logging and SNMP notifications
Enabling logging for neighbor state changes
About this task
With this feature enabled, the router delivers logs about neighbor state changes to its information center. The information center processes logs according to user-defined output rules (whether to output logs and where to output). For more information about the information center, see information center configuration in System Management Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable logging for neighbor state changes. log-peer-change
By default, this feature is enabled.
Setting the maximum number of OSPFv3 logs
About this task
OSPFv3 logs include route calculation logs, neighbor logs, and LSA aging logs.
Procedure
1. Enter system view. system-view
542
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Set the maximum number of OSPFv3 logs. event-log { lsa-flush | peer | spf } size count
By default, the maximum number of LSA aging logs, neighbor logs, or route calculation logs is
10.
Configuring OSPFv3 network management
About this task
This task involves the following configurations:
•
Bind an OSPFv3 process to MIB so that you can use network management software to manage the specified OSPFv3 process.
•
Enable SNMP notifications for OSPFv3 to report important events.
•
Set the SNMP notification output interval and the maximum number of SNMP notifications that can be output at each interval.
To report critical OSPFv3 events to an NMS, enable SNMP notifications for OSPFv3. For SNMP notifications to be sent correctly, you must also configure SNMP on the device. For more information about SNMP configuration, see the network management and monitoring configuration guide for the device.
The standard OSPFv3 MIB provides only single-instance MIB objects. To identify multiple OSPFv3 processes in the standard OSPFv3 MIB, you must assign a unique context name to each OSPFv3 process.
Context is a method introduced to SNMPv3 for multiple-instance management. For SNMPv1/v2c, you must specify a community name as a context name for protocol identification.
Procedure
1. Enter system view. system-view
2. Bind MIB to an OSPFv3 process.
ospfv3 mib-binding process-id
By default, MIB is bound to the process with the smallest process ID.
3. Enable SNMP notifications for OSPFv3. snmp-agent trap enable ospfv3 [ grrestarter-status-change | grhelper-status-change | if-state-change | if-cfg-error | if-bad-pkt | neighbor-state-change | nssatranslator-status-change | virtif-bad-pkt | virtif-cfg-error | virtif-state-change | virtgrhelper-status-change | virtgrhelper-status-change ]*
By default, SNMP notifications for OSPFv3 are enabled.
4. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
5. Configure an SNMP context for the OSPFv3 process. snmp context-name context-name
By default, no SNMP context is configured for the OSPFv3 process.
6. (Optional.) Set the SNMP notification output interval and the maximum number of SNMP notifications that can be output at each interval.
snmp trap rate-limit interval trap-interval count trap-number
543
By default, OSPFv3 outputs a maximum of seven SNMP notifications within 10 seconds.
Verifying and maintaining OSPFv3
Verifying OSPFv3 configuration and running status
Verifying basic OSPFv3 configuration and running status
Perform display tasks in any view.
•
Display OSPFv3 process information. display ospfv3 [ process-id ] [ verbose ]
•
Display OSPFv3 ABR and ASBR information. display ospfv3 [ process-id ] abr-asbr
•
Display OSPFv3 interface information. display ospfv3 [ process-id ] interface [ interface-type
interface-number | verbose ]
•
Display OSPFv3 LSDB information. display ospfv3 [ process-id ] lsdb [ { external | grace | inter-prefix
| inter-router | intra-prefix | link | network | nssa | router | unknown
[ type ] } [ link-state-id ] [ originate-router router-id | self-originate ] | statistics | total | verbose ]
•
Display OSPFv3 next hop information. display ospfv3 [ process-id ] nexthop
•
Display OSPFv3 neighbor information. display ospfv3 [ process-id ] [ area area-id ] peer [ [ interface-type interface-number ] [ verbose ] | peer-router-id | statistics ]
•
Display OSPFv3 routing table information. display ospfv3 [ process-id ] routing [ ipv6-address prefix-length ]
•
Display OSPFv3 topology information. display ospfv3 [ process-id ] [ area area-id ] spf-tree [ verbose ]
Verifying OSPFv3 request queue and retransmission queue configuration
Perform display tasks in any view.
•
Display OSPFv3 request queue information. display ospfv3 [ process-id ] [ area area-id ] request-queue
[ interface-type interface-number ] [ neighbor-id ]
•
Display OSPFv3 retransmission queue information. display ospfv3 [ process-id ] [ area area-id ] retrans-queue
[ interface-type interface-number ] [ neighbor-id ]
Verifying OSPFv3 virtual link configuration
To display OSPFv3 virtual link information, execute the following command in any view: display ospfv3 [ process-id ] vlink
Verifying OSPFv3 network reliability configuration and status
Perform display tasks in any view.
•
Display OSPFv3 GR information.
544
display ospfv3 [ process-id ] graceful-restart [ verbose ]
•
Display OSPFv3 NSR information. display ospfv3 [ process-id ] non-stop-routing
Verifying OSPFv3 route summarization configuration
About this task
You can configure route summarization for OSPFv3 inter-area or redistributed routes. Perform this task to view OSPFv3 ABR or ASBR route summarization information.
Procedure
Perform display tasks in any view.
•
Display OSPFv3 ABR route summarization information. display ospfv3 [ process-id ] [ area area-id ] abr-summary [ ipv6-address prefix-length ] [ verbose ]
•
Display OSPFv3 ASBR route summarization information. display ospfv3 [ process-id ] asbr-summary [ ipv6-address prefix-length ] [ verbose ]
Displaying and clearing OSPFv3 log information
To display OSPFv3 log information, execute the following command in any view: display ospfv3 [ process-id ] event-log { lsa-flush | peer | spf }
To clear OSPFv3 log information, execute the following command in user view: reset ospfv3 [ process-id ] event-log [ lsa-flush | peer | spf ]
Displaying and clearing OSPFv3 statistics
Displaying OSPFv3 statistics
Perform display tasks in any view.
•
Display OSPFv3 packet statistics. display ospfv3 [ process-id ] statistics [ error ]
•
Display global OSPFv3 statistics. display ospfv3 global-statistics [ public | vpn-instance
vpn-instance-name ]
Clearing OSPFv3 statistics
To clear OSPFv3 statistics, execute the following command in user view: reset ospfv3 [ process-id ] statistics
Restarting an OSPFv3 process
To restart an OSPFv3 process, execute the following command in user view: reset ospfv3 [ process-id ] process [ graceful-restart ]
This command will terminate the neighbor relationships of the process.
545
Restarting OSPFv3 route redistribution
To restart OSPFv3 route redistribution, execute the following command in user view: reset ospfv3 [ process-id ] redistribution
OSPFv3 configuration examples
Example: Configuring OSPFv3 stub area
Network configuration
•
Enable OSPFv3 on all devices.
•
Split the AS into three areas.
•
Configure Device B and Device C as ABRs to forward routing information between areas.
•
Configure Area 2 as a stub area to reduce LSAs in the area without affecting route reachability.
Figure 115 Network diagram
Device B
HGE1/0/1
OSPFv3
Area 0
2001::1/64
HGE1/0/1
2001::2/64
HGE1/0/2
2001:1::1/64
Device C
HGE1/0/2
2001:2::1/64
OSPFv3
Area 1 HGE1/0/2
2001:1::2/64
OSPFv3
Area 2
HGE1/0/2
2001:2::2/64
Device A
HGE1/0/1
2001:3::1/64 Stub
Device D
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Device A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ospfv3 1 area 1
[DeviceA-HundredGigE1/0/2] quit
# On Device B, enable OSPFv3 and specify the router ID as 2.2.2.2.
<DeviceB> system-view
[DeviceB] ospfv3 1
546
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ospfv3 1 area 1
[DeviceB-HundredGigE1/0/2] quit
# On Device C, enable OSPFv3 and specify the router ID as 3.3.3.3.
<DeviceC> system-view
[DeviceC] ospfv3 1
[DeviceC-ospfv3-1] router-id 3.3.3.3
[DeviceC-ospfv3-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceC-HundredGigE1/0/2] quit
# On Device D, enable OSPFv3 and specify the router ID as 4.4.4.4.
<DeviceD> system-view
[DeviceD] ospfv3 1
[DeviceD-ospfv3-1] router-id 4.4.4.4
[DeviceD-ospfv3-1] quit
[DeviceD] interface hundredgige 1/0/2
[DeviceD-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceD-HundredGigE1/0/2] quit
# Display OSPFv3 neighbors on Device B.
[DeviceB] display ospfv3 peer
OSPFv3 Process 1 with Router ID 2.2.2.2
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
3.3.3.3 1 Full/BDR 00:00:40 0 HGE1/0/1
Area: 0.0.0.1
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
1.1.1.1 1 Full/DR 00:00:40 0 HGE1/0/2
# Display OSPFv3 neighbors on Device C.
[DeviceC] display ospfv3 peer
OSPFv3 Process 1 with Router ID 3.3.3.3
Area: 0.0.0.0
-------------------------------------------------------------------------
547
Router ID Pri State Dead-Time InstID Interface
2.2.2.2 1 Full/DR 00:00:40 0 HGE1/0/1
Area: 0.0.0.2
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
4.4.4.4 1 Full/BDR 00:00:40 0 HGE1/0/2
# Display OSPFv3 neighbors on Device D.
[DeviceD] display ospfv3 routing
OSPFv3 Process 1 with Router ID 4.4.4.4
-------------------------------------------------------------------------
I - Intra area route, E1 - Type 1 external route, N1 - Type 1 NSSA route
IA - Inter area route, E2 - Type 2 external route, N2 - Type 2 NSSA route
* - Selected route
*Destination: 2001::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000004 Cost : 2
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:1::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000004 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:2::/64
Type : I Area : 0.0.0.2
AdvRouter : 4.4.4.4 Preference : 10
NibID : 0x23000002 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : ::
BkNexthop : N/A
Status : Direct
*Destination: 2001:3::1/128
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000004 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
548
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
Total: 4
Intra area: 1 Inter area: 3 ASE: 0 NSSA: 0
3. Configure Area 2 as a stub area:
# Configure Device D.
[DeviceD] ospfv3
[DeviceD-ospfv3-1] area 2
[DeviceD-ospfv3-1-area-0.0.0.2] stub
[DeviceD-ospfv3-1-area-0.0.0.2] quit
[DeviceD-ospfv3-1] quit
# Configure Device C, and specify the cost of the default route sent to the stub area as 10.
[DeviceC] ospfv3
[DeviceC-ospfv3-1] area 2
[DeviceC-ospfv3-1-area-0.0.0.2] stub
[DeviceC-ospfv3-1-area-0.0.0.2] default-cost 10
# Display OSPFv3 routing table on Device D.
[DeviceD] display ospfv3 routing
OSPFv3 Process 1 with Router ID 4.4.4.4
-------------------------------------------------------------------------
I - Intra area route, E1 - Type 1 external route, N1 - Type 1 NSSA route
IA - Inter area route, E2 - Type 2 external route, N2 - Type 2 NSSA route
* - Selected route
*Destination: ::/0
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 11
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 2
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:1::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
549
NibID : 0x23000003 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:2::/64
Type : I Area : 0.0.0.2
AdvRouter : 4.4.4.4 Preference : 10
NibID : 0x23000001 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : ::
BkNexthop : N/A
Status : Direct
*Destination: 2001:3::1/128
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
Total: 5
Intra area: 1 Inter area: 4 ASE: 0 NSSA: 0
The output shows that a default route is added and its cost is the cost of a direct route plus the configured cost.
4. Configure Area 2 as a totally stub area to further reduce the stub area routing table size:
# Configure Area 2 as a totally stub area on Device C.
[DeviceC-ospfv3-1-area-0.0.0.2] stub no-summary
# Display OSPFv3 routing table on Device D.
[DeviceD] display ospfv3 routing
OSPFv3 Process 1 with Router ID 4.4.4.4
-------------------------------------------------------------------------
I - Intra area route, E1 - Type 1 external route, N1 - Type 1 NSSA route
IA - Inter area route, E2 - Type 2 external route, N2 - Type 2 NSSA route
* - Selected route
*Destination: ::/0
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 11
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
550
*Destination: 2001:2::/64
Type : I Area : 0.0.0.2
AdvRouter : 4.4.4.4 Preference : 10
NibID : 0x23000001 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : ::
BkNexthop : N/A
Status : Direct
Total: 2
Intra area: 1 Inter area: 1 ASE: 0 NSSA: 0
The output shows that route entries are reduced. All indirect routes are removed, except the default route.
Example: Configuring OSPFv3 NSSA area
Network configuration
•
Configure OSPFv3 on all devices and split the AS into three areas.
•
Configure Device B and Device C as ABRs to forward routing information between areas.
•
Configure Area 1 as an NSSA area and configure Device A as an ASBR to redistribute static routes into the AS.
Figure 116 Network diagram
OSPFv3
Area 1
Device B
HGE1/0/1
OSPFv3
Area 0
2001::1/64
HGE1/0/1
2001::2/64
HGE1/0/2
2001:1::1/64
Device C
HGE1/0/2
2001:2::1/64
HGE1/0/2
2001:1::2/64
OSPFv3
Area 2
HGE1/0/2
2001:2::2/64
Device A
HGE1/0/1
2001:3::1/64
Stub
Device D
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2.
Configure basic OSPFv3 (see " Example: Configuring OSPFv3 stub area ").
3. Configure Area 1 as an NSSA area:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospfv3
[DeviceA-ospfv3-1] area 1
[DeviceA-ospfv3-1-area-0.0.0.1] nssa
[DeviceA-ospfv3-1-area-0.0.0.1] quit
[DeviceA-ospfv3-1] quit
551
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospfv3
[DeviceB-ospfv3-1] area 1
[DeviceB-ospfv3-1-area-0.0.0.1] nssa
[DeviceB-ospfv3-1-area-0.0.0.1] quit
[DeviceB-ospfv3-1] quit
# Display OSPFv3 routing information on Device D.
[DeviceD] display ospfv3 1 routing
OSPFv3 Process 1 with Router ID 4.4.4.4
-------------------------------------------------------------------------
I - Intra area route, E1 - Type 1 external route, N1 - Type 1 NSSA route
IA - Inter area route, E2 - Type 2 external route, N2 - Type 2 NSSA route
* - Selected route
*Destination: 2001::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 2
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:1::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:2::/64
Type : I Area : 0.0.0.2
AdvRouter : 4.4.4.4 Preference : 10
NibID : 0x23000001 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : ::
BkNexthop : N/A
Status : Direct
*Destination: 2001:3::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000003 Cost : 4
Interface : HGE1/0/2 BkInterface: N/A
552
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
Total: 4
Intra area: 1 Inter area: 3 ASE: 0 NSSA: 0
4. Configure route redistribution:
# Configure an IPv6 static route, and configure OSPFv3 to redistribute the static route on
Device A.
[DeviceA] ipv6 route-static 1234:: 64 null 0
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] import-route static
[DeviceA-ospfv3-1] quit
# Display OSPFv3 routing information on Device D.
[DeviceD] display ospfv3 1 routing
OSPFv3 Process 1 with Router ID 4.4.4.4
-------------------------------------------------------------------------
I - Intra area route, E1 - Type 1 external route, N1 - Type 1 NSSA route
IA - Inter area route, E2 - Type 2 external route, N2 - Type 2 NSSA route
* - Selected route
*Destination: 2001::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000002 Cost : 2
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:1::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000002 Cost : 3
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 2001:2::/64
Type : I Area : 0.0.0.2
AdvRouter : 4.4.4.4 Preference : 10
NibID : 0x23000004 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : ::
BkNexthop : N/A
Status : Direct
553
*Destination: 2001:3::/64
Type : IA Area : 0.0.0.2
AdvRouter : 3.3.3.3 Preference : 10
NibID : 0x23000002 Cost : 4
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Rely
*Destination: 1234::/64
Type : E2 Tag : 1
AdvRouter : 2.2.2.2 Preference : 150
NibID : 0x23000001 Cost : 1
Interface : HGE1/0/2 BkInterface: N/A
Nexthop : FE80::48C0:26FF:FEDA:305
BkNexthop : N/A
Status : Normal
Total: 5
Intra area: 1 Inter area: 3 ASE: 1 NSSA: 0
The output shows an AS external route imported from the NSSA area exists on Device D.
Example: Configuring OSPFv3 DR election
Network configuration
•
Configure router priority 100 for Device A, the highest priority on the network, so it will become the DR.
•
Configure router priority 2 for Device C, the second highest priority on the network, so it will become the BDR.
•
Configure router priority 0 for Device B, so it cannot become a DR or BDR.
•
Device D uses the default router priority 1.
Figure 117 Network diagram
Device A Device B
HGE1/0/1
2001::1/64
HGE1/0/1
2001::2/64
HGE1/0/1
2001::3/64
Device C
HGE1/0/1
2001::4/64
Device D
554
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Device A, enable OSPFv3, and specify the router ID as 1.1.1.1.
<DeviceA> system-view
[DeviceA] ospfv3
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceA-HundredGigE1/0/1] quit
# On Device B, enable OSPFv3, and specify the router ID as 2.2.2.2.
<DeviceB> system-view
[DeviceB] ospfv3
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceB-HundredGigE1/0/1] quit
# On Device C, enable OSPFv3, and specify the router ID as 3.3.3.3.
<DeviceC> system-view
[DeviceC] ospfv3
[DeviceC-ospfv3-1] router-id 3.3.3.3
[DeviceC-ospfv3-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceC-HundredGigE1/0/1] quit
# On Device D, enable OSPFv3, and specify the router ID as 4.4.4.4.
<DeviceD> system-view
[DeviceD] ospfv3
[DeviceD-ospfv3-1] router-id 4.4.4.4
[DeviceD-ospfv3-1] quit
[DeviceD] interface hundredgige 1/0/1
[DeviceD-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceD-HundredGigE1/0/1] quit
# Display neighbors on Device A. The Devices have the same default router priority 1, so
Device D (the router with the highest router ID) is elected as the DR, and Device C is the BDR.
[DeviceA] display ospfv3 peer
OSPFv3 Process 1 with Router ID 1.1.1.1
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
2.2.2.2 1 2-Way/DROther 00:00:36 0 HGE1/0/1
3.3.3.3 1 Full/BDR 00:00:35 0 HGE1/0/1
4.4.4.4 1 Full/DR 00:00:33 0 HGE1/0/1
# Display neighbors on Device D. The neighbor states are all full.
555
[DeviceD] display ospfv3 peer
OSPFv3 Process 1 with Router ID 4.4.4.4
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
1.1.1.1 1 Full/DROther 00:00:30 0 HGE1/0/1
2.2.2.2 1 Full/DROther 00:00:37 0 HGE1/0/1
3.3.3.3 1 Full/BDR 00:00:31 0 HGE1/0/1
3. Configure router priorities for interfaces:
# Set the router priority to 100 for the interface HundredGigE 1/0/1 of Device A.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 dr-priority 100
[DeviceA-HundredGigE1/0/1] quit
# Set the router priority to 0 for the interface HundredGigE 1/0/1 of Device B.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 dr-priority 0
[DeviceB-HundredGigE1/0/1] quit
# Set the router priority to 2 for the interface HundredGigE 1/0/1 of Device C.
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 dr-priority 2
[DeviceC-HundredGigE1/0/1] quit
# Display neighbors on DeviceA. The output shows that the router priorities have been changed, but the DR and BDR are not changed.
[DeviceA] display ospfv3 peer
OSPFv3 Process 1 with Router ID 1.1.1.1
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
2.2.2.2 0 2-Way/DROther 00:00:36 0 HGE1/0/1
3.3.3.3 2 Full/BDR 00:00:35 0 HGE1/0/1
4.4.4.4 1 Full/DR 00:00:33 0 HGE1/0/1
# Display neighbors on Device D.
[DeviceD] display ospfv3 peer
OSPFv3 Process 1 with Router ID 4.4.4.4
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
1.1.1.1 100 Full/DROther 00:00:30 0 HGE1/0/1
2.2.2.2 0 Full/DROther 00:00:37 0 HGE1/0/1
3.3.3.3 2 Full/BDR 00:00:31 0 HGE1/0/1
The output shows that the DR is still Device D.
4. Enable DR/BDR election:
556
# Perform the shutdown and undo shutdown commands on each interface to enable a new
DR/BD election. (Details not shown.)
# Display neighbors on Device A. The output shows that Device C becomes the BDR.
[DeviceA] display ospfv3 peer
OSPFv3 Process 1 with Router ID 1.1.1.1
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
2.2.2.2 0 Full/DROther 00:00:36 0 HGE1/0/1
3.3.3.3 2 Full/BDR 00:00:35 0 HGE1/0/1
4.4.4.4 1 Full/DROther 00:00:33 0 HGE1/0/1
# Display neighbors on Device D.
[DeviceD] display ospfv3 peer
OSPFv3 Process 1 with Router ID 4.4.4.4
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
1.1.1.1 100 Full/DR 00:00:30 0 HGE1/0/1
2.2.2.2 0 2-Way/DROther 00:00:37 0 HGE1/0/1
3.3.3.3 2 Full/BDR 00:00:31 0 HGE1/0/1
The output shows that Device A becomes the DR.
Example: Configuring OSPFv3 route redistribution
Network configuration
•
Device A, Device B, and Device C are in Area 2.
•
OSPFv3 process 1 and OSPFv3 process 2 run on Device B. Device B communicates with
Device A and Device C through OSPFv3 process 1 and OSPFv3 process 2.
•
Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process
1 on Device B, and set the metric for redistributed routes to 3. Device C can then learn the routes destined for 1::0/64 and 2::0/64, and Device A cannot learn the routes destined for
3::0/64 or 4::0/64.
Figure 118 Network diagram
HGE1/0/1
2::1/64
Device A
HGE1/0/2
1::1/64
Process 1
Area 2
HGE1/0/2
1::2/64
Device B
HGE1/0/1
3::1/64
557
HGE1/0/2
3::2/64
Process 2
Area 2
Device C
HGE1/0/1
4::1/64
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# Enable OSPFv3 process 1 on Device A.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 2
[DeviceA-HundredGigE1/0/1] quit
# Enable OSPFv3 process 1 and OSPFv3 process 2 on Device B.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceB-HundredGigE1/0/2] quit
[DeviceB] ospfv3 2
[DeviceB-ospfv3-2] router-id 3.3.3.3
[DeviceB-ospfv3-2] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 2 area 2
[DeviceB-HundredGigE1/0/1] quit
# Enable OSPFv3 process 2 on Device C.
<DeviceC> system-view
[DeviceC] ospfv3 2
[DeviceC-ospfv3-2] router-id 4.4.4.4
[DeviceC-ospfv3-2] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ospfv3 2 area 2
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 2 area 2
[DeviceC-HundredGigE1/0/1] quit
# Display the routing table on Device C.
[DeviceC] display ipv6 routing-table
Destinations : 7 Routes : 7
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
558
Destination: 3::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 3::2/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 4::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
3. Configure OSPFv3 route redistribution:
# Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process 1 on Device B, and set the metric for redistributed routes to 3.
[DeviceB] ospfv3 2
[DeviceB-ospfv3-2] import-route ospfv3 1 cost 3
[DeviceB-ospfv3-2] import-route direct cost 3
[DeviceB-ospfv3-2] quit
# Display the routing table on Device C.
[DeviceC] display ipv6 routing-table
Destinations : 9 Routes : 9
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 3
Destination: 2::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 3
Destination: 3::/64 Protocol : Direct
559
NextHop : :: Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 3::2/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : Direct
NextHop : :: Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 4::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Example: Configuring OSPFv3 route summarization
Network configuration
•
Device A, Device B, and Device C are in Area 2.
•
OSPFv3 process 1 and OSPFv3 process 2 run on Device B. Device B communicates with
Device A and Device C through OSPFv3 process 1 and OSPFv3 process 2, respectively.
•
On Device A, configure IPv6 addresses 2:1:1::1/64, 2:1:2::1/64, and 2:1:3::1/64 for
HundredGigE 1/0/1.
•
On Device B, configure OSPFv3 process 2 to redistribute direct routes and the routes from
OSPFv3 process 1. Device C can then learn the routes destined for 2::/64, 2:1:1::/64, 2:1:2::/64, and 2:1:3::/64.
•
On Device B, configure route summarization to advertise only summary route 2::/16 to Device
C.
Figure 119 Network diagram
HGE1/0/1
2::1/64
Device A
HGE1/0/2
1::1/64
Process 1
Area 2
HGE1/0/2
1::2/64
Device B
HGE1/0/1
3::1/64
560
HGE1/0/2
3::2/64
Process 2
Area 2
Device C
HGE1/0/1
4::1/64
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3:
# Enable OSPFv3 process 1 on Device A.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ipv6 address 2:1:1::1 64
[DeviceA-HundredGigE1/0/1] ipv6 address 2:1:2::1 64
[DeviceA-HundredGigE1/0/1] ipv6 address 2:1:3::1 64
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 2
[DeviceA-HundredGigE1/0/1] quit
# Enable OSPFv3 process 1 and OSPFv3 process 2 on Device B.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ospfv3 1 area 2
[DeviceB-HundredGigE1/0/2] quit
[DeviceB] ospfv3 2
[DeviceB-ospfv3-2] router-id 3.3.3.3
[DeviceB-ospfv3-2] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 2 area 2
[DeviceB-HundredGigE1/0/1] quit
# Enable OSPFv3 process 2 on Device C.
<DeviceC> system-view
[DeviceC] ospfv3 2
[DeviceC-ospfv3-2] router-id 4.4.4.4
[DeviceC-ospfv3-2] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ospfv3 2 area 2
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 2 area 2
[DeviceC-HundredGigE1/0/1] quit
3. Configure OSPFv3 route redistribution:
# Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process 1 on Device B.
[DeviceB] ospfv3 2
[DeviceB-ospfv3-2] import-route ospfv3 1
[DeviceB-ospfv3-2] import-route direct
561
[DeviceB-ospfv3-2] quit
# Display the routing table on Device C.
[DeviceC] display ipv6 routing-table
Destinations : 12 Routes : 12
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 2::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 2:1:1::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 2:1:2::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 2:1:3::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 3::2/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : Direct
NextHop : 4::1 Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 4::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
562
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
4. Configure ASBR route summarization:
# On Device B, configure OSPFv3 process 2 to advertise a summary route 2::/16.
[DeviceB] ospfv3 2
[DeviceB-ospfv3-2] asbr-summary 2:: 16
[DeviceB-ospfv3-2] quit
# Display the routing table on Device C.
[DeviceC] display ipv6 routing-table
Destinations : 9 Routes : 9
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 2::/16 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : HGE1/0/2 Cost : 1
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
Interface : HGE1/0/2 Cost : 0
Destination: 3::2/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : Direct
NextHop : 4::1 Preference: 0
Interface : HGE1/0/1 Cost : 0
Destination: 4::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
563
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Example: Configuring OSPFv3 GR
Network configuration
•
Device A, Device B, and Device C that reside in the same AS and the same OSPFv3 routing domain are GR capable.
•
Device A acts as the GR restarter. Device B and Device C act as GR helpers, and synchronize their LSDBs with Device A through GR.
Figure 120 Network diagram
Router ID: 1.1.1.1
GR restarter
Device A
HGE1/0/1
2000::1/24
HGE1/0/1
2000::2/24
HGE1/0/1
2000::3/24
Device B Device C
GR helper
Router ID: 2.2.2.2
GR helper
Router ID: 3.3.3.3
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Device A, enable OSPFv3 process 1, enable GR, and set the router ID to 1.1.1.1.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] graceful-restart enable
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceA-HundredGigE1/0/1] quit
# On Device B, enable OSPFv3 and set the router ID to 2.2.2.2. (By default, GR helper is enabled on a router.)
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceB-HundredGigE1/0/1] quit
564
# On Device C, enable OSPFv3 and set the router ID to 3.3.3.3. (By default, GR helper is enabled on a router.)
<DeviceC> system-view
[DeviceC] ospfv3 1
[DeviceC-ospfv3-1] router-id 3.3.3.3
[DeviceC-ospfv3-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceC-HundredGigE1/0/1] quit
Verifying the configuration
# Perform an active/standby switchover on Device A to trigger an OSPFv3 GR operation. (Details not shown.)
Example: Configuring OSPFv3 NSR
Network configuration
As shown in Figure 121 , Device S, Device A, and Device B belong to the same OSPFv3 routing
domain. Enable OSPFv3 NSR on Device S to ensure correct routing when an active/standby switchover occurs on Device S.
Figure 121 Network diagram
Loop 0
2002::2/128
Device A
HGE1/0/1
1200:1::1/64
HGE1/0/1
1200:1::2/64
Device S
HGE1/0/2
1400:1::2/64
HGE1/0/1
1400:1::1/64
Device B
Loop 0
4004::4/128
Procedure
1. Configure IP addresses and subnet masks for interfaces on the devices. (Details not shown.)
2. Configure OSPFv3 on the devices to ensure that Device S, Device A, and Device B can communicate with each other at Layer 3. (Details not shown.)
3. Configure OSPFv3:
# On Device A, enable OSPFv3 and set the router ID to 1.1.1.1.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceA-HundredGigE1/0/1] quit
# On Device B, enable OSPFv3 and set the router ID to 2.2.2.2.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceB-HundredGigE1/0/1] quit
565
# On Device S, enable OSPFv3, set the router ID to 3.3.3.3, and enable NSR.
<DeviceS> system-view
[DeviceS] ospfv3 1
[DeviceS-ospfv3-1] router-id 3.3.3.3
[DeviceS-ospfv3-1] non-stop-routing
[DeviceS-ospfv3-1] quit
[DeviceS] interface hundredgige 1/0/1
[DeviceS-HundredGigE1/0/1] ospfv3 1 area 1
[DeviceS-HundredGigE1/0/1] quit
[DeviceS] interface hundredgige 1/0/2
[DeviceS-HundredGigE1/0/2] ospfv3 1 area 1
[DeviceS-HundredGigE1/0/2] quit
Verifying the configuration
# Verify the following:
•
When an active/standby switchover occurs on Device S, the neighbor relationships and routing information on Device A and Device B have not changed. (Details not shown.)
•
The traffic from Device A to Device B has not been impacted. (Details not shown.)
Example: Configuring BFD for OSPFv3
Network configuration
•
Configure OSPFv3 on Device A, Device B and Device C and configure BFD over the link
Device A<—>L2 Switch<—>Device B.
•
After the link Device A<—>L2 Switch<—>Device B fails, BFD can quickly detect the failure and notify OSPFv3 of the failure. Then Device A and Device B communicate through Device C.
Figure 122 Network diagram
2001:1::/64
Device A
HGE1/0/1
HGE1/0/2
BFD
HGE1/0/1
Device B
2001:4::/64
L2 Switch HGE1/0/2
Area 0
HGE1/0/1 HGE1/0/2
Device C
Table 28 Interface and IP address assignment
Device
Device A
Device A
Device B
Interface
HGE1/0/1
HGE1/0/2
HGE1/0/1
566
IPv6 address
2001::1/64
2001:2::1/64
2001::2/64
Device
Device B
Device C
Interface
HGE1/0/2
HGE1/0/1
IPv6 address
2001:3::2/64
2001:2::2/64
Device C HGE1/0/2 2001:3::1/64
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# Enable OSPFv3 and set the router ID to 1.1.1.1 on Device A.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ospfv3 1 area 0
[DeviceA-HundredGigE1/0/2] quit
# Enable OSPFv3 and set the router ID to 2.2.2.2 on Device B.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ospfv3 1 area 0
[DeviceB-HundredGigE1/0/2] quit
# Enable OSPFv3 and set the router ID to 3.3.3.3 on Device C.
<DeviceC> system-view
[DeviceC] ospfv3 1
[DeviceC-ospfv3-1] router-id 3.3.3.3
[DeviceC-ospfv3-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ospfv3 1 area 0
[DeviceC-HundredGigE1/0/2] quit
3. Configure BFD:
# Enable BFD and configure BFD parameters on Device A.
[DeviceA] bfd session init-mode active
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ospfv3 bfd enable
567
[DeviceA-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceA-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceA-HundredGigE1/0/1] bfd detect-multiplier 7
[DeviceA-HundredGigE1/0/1] return
# Enable BFD and configure BFD parameters on Device B.
[DeviceB] bfd session init-mode active
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 bfd enable
[DeviceB-HundredGigE1/0/1] bfd min-transmit-interval 500
[DeviceB-HundredGigE1/0/1] bfd min-receive-interval 500
[DeviceB-HundredGigE1/0/1] bfd detect-multiplier 6
Verifying the configuration
# Display the BFD information on Device A.
<DeviceA> display bfd session
Total sessions: 1 Up sessions: 1 Init mode: Active
IPv6 session working in control packet mode:
Local discr: 1441 Remote discr: 1450
Source IP: FE80::20F:FF:FE00:1202 (link-local address of HundredGigE1/0/1 on
Router A)
Destination IP: FE80::20F:FF:FE00:1200 (link-local address of HundredGigE1/0/1 on
Router B)
Session state: Up Interface: HGE1/0/1
Hold time: 2319ms
# Display routes destined for 2001:4::0/64 on Device A.
<DeviceA> display ipv6 routing-table 2001:4::0 64
Summary Count : 1
Destination: 2001:4::/64 Protocol : O_INTRA
NextHop : FE80::20F:FF:FE00:1200 Preference: 10
Interface : HGE1/0/1 Cost : 1
The output shows that Device A communicates with Device B through HundredGigE 1/0/1. Then the link over HundredGigE 1/0/1 fails.
# Display routes destined for 2001:4::0/64 on Device A.
<DeviceA> display ipv6 routing-table 2001:4::0 64
Summary Count : 1
Destination: 2001:4::/64 Protocol : O_INTRA
NextHop : FE80::BAAF:67FF:FE27:DCD0 Preference: 10
Interface : HGE1/0/2 Cost : 2
The output shows that Device A communicates with Device B through HundredGigE 1/0/2.
568
Example: Configuring OSPFv3 FRR
Network configuration
As shown in Figure 123 , Device A, Device B, and Device C reside in the same OSPFv3 domain.
Configure OSPFv3 FRR so that when Link A fails, traffic is immediately switched to Link B.
Figure 123 Network diagram
Device C
HGE
1/0
/1
Link B
HGE
1/0
/2
HGE
1/0
/1
Link A
Loop0
Device A
HGE1/0/2
Table 29 Interface and IP address assignment
HGE
1/0
/1
HGE1/0/2
Device B
Loop0
Device
Device A
Interface
HGE1/0/1
HGE1/0/2
Loop0
IP address
1::1/64
2::1/64
10::1/128
Device
Device B
Interface
HGE1/0/1
HGE1/0/2
Loop0
IP address
3::1/64
2::2/64
20::1/128
Device C HGE1/0/1 1::2/64
HGE1/0/2 3::2/64
Procedure
1. Configure IPv6 addresses for interfaces on the devices. (Details not shown.)
2. Configure OSPFv3 on the devices to ensure that Device A, Device B, and Device C can communicate with each other at the network layer. (Details not shown.)
3. Configure OSPFv3 FRR:
You can enable OSPFv3 FRR to either calculate a backup next hop by using the LFA algorithm, or specify a backup next hop by using a routing policy.
(Method 1.) Enable OSPFv3 FRR to calculate a backup next hop by using the LFA algorithm:
# Configure Device A.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] fast-reroute lfa
[DeviceA-ospfv3-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] fast-reroute lfa
[DeviceB-ospfv3-1] quit
(Method 2.) Enable OSPFv3 FRR to specify a backup next hop by using a routing policy:
# Configure Device A.
569
<DeviceA> system-view
[DeviceA] ipv6 prefix-list abc index 10 permit 20::1 128
[DeviceA] route-policy frr permit node 10
[DeviceA-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceA-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 1::2
[DeviceA-route-policy-frr-10] quit
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] fast-reroute route-policy frr
[DeviceA-ospfv3-1] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] ipv6 prefix-list abc index 10 permit 10::1 128
[DeviceB] route-policy frr permit node 10
[DeviceB-route-policy-frr-10] if-match ipv6 address prefix-list abc
[DeviceB-route-policy-frr-10] apply ipv6 fast-reroute backup-interface hundredgige 1/0/1 backup-nexthop 3::2
[DeviceB-route-policy-frr-10] quit
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] fast-reroute route-policy frr
[DeviceB-ospfv3-1] quit
Verifying the configuration
# Display the route 20::1/128 on Device A to view the backup next hop information.
[DeviceA] display ipv6 routing-table 20::1 128 verbose
Summary count : 1
Destination: 20::1/128
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 00h03m45s
Cost: 6 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x23000005 LastAs: 0
AttrID: 0xffffffff Neighbor: ::
Flags: 0x10041 OrigNextHop: FE80::7685:45FF:FEAD:102
Label: NULL RealNextHop: FE80::7685:45FF:FEAD:102
BkLabel: NULL BkNextHop: FE80::34CD:9FF:FE2F:D02
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
570
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
# Display the route 10::1/128 on Device B to view the backup next hop information.
[DeviceB] display ipv6 routing-table 10::1 128 verbose
Summary count : 1
Destination: 10::1/128
Protocol: O_INTRA
Process ID: 1
SubProtID: 0x1 Age: 00h03m10s
Cost: 1 Preference: 10
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NibID: 0x23000006 LastAs: 0
AttrID: 0xffffffff Neighbor: ::
Flags: 0x10041 OrigNextHop: FE80::34CC:E8FF:FE5B:C02
Label: NULL RealNextHop: FE80::34CC:E8FF:FE5B:C02
BkLabel: NULL BkNextHop: FE80::7685:45FF:FEAD:102
SRLabel: NULL BkSRLabel: NULL
SIDIndex: NULL InLabel: NULL
Tunnel ID: Invalid Interface: HundredGigE1/0/2
BkTunnel ID: Invalid BkInterface: HundredGigE1/0/1
FtnIndex: 0x0 TrafficIndex: N/A
Connector: N/A PathID: 0x0
SRTunnelID: Invalid
SID Type: N/A Exp: N/A
VpnPeerId: N/A Dscp: N/A
Example: Configuring OSPFv3 IPsec profile
Network configuration
As shown in Figure 124 , all devices run OSPFv3, and the AS is divided into two areas.
Configure IPsec profiles on the devices to authenticate and encrypt protocol packets.
571
Figure 124 Network diagram
OSPFv3
Area 1
Device B
HGE1/0/1
OSPFv3
Area 0
2001::1/64
HGE1/0/2
2001:1::1/64
HGE1/0/1
2001::2/64
Device C
HGE1/0/2
2001:1::2/64
Device A
Procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 basic features:
# On Device A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<DeviceA> system-view
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] router-id 1.1.1.1
[DeviceA-ospfv3-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ospfv3 1 area 1
[DeviceA-HundredGigE1/0/2] quit
# On Device B, enable OSPFv3 and specify the router ID as 2.2.2.2.
<DeviceB> system-view
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] router-id 2.2.2.2
[DeviceB-ospfv3-1] quit
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceB-HundredGigE1/0/1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ospfv3 1 area 1
[DeviceB-HundredGigE1/0/2] quit
# On Device C, enable OSPFv3 and specify the router ID as 3.3.3.3.
<DeviceC> system-view
[DeviceC] ospfv3 1
[DeviceC-ospfv3-1] router-id 3.3.3.3
[DeviceC-ospfv3-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] ospfv3 1 area 0
[DeviceC-HundredGigE1/0/1] quit
3. Configure OSPFv3 IPsec profiles:
On Device A:
# Create an IPsec transform set named trans .
[DeviceA] ipsec transform-set trans
572
# Specify the encapsulation mode as transport .
[DeviceA-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[DeviceA-ipsec-transform-set-trans] protocol esp
[DeviceA-ipsec-transform-set-trans] esp encryption-algorithm aes-cbc-128
[DeviceA-ipsec-transform-set-trans] esp authentication-algorithm sha1
[DeviceA-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile001 .
[DeviceA] ipsec profile profile001 manual
# Use IPsec transform set trans .
[DeviceA-ipsec-profile-manual-profile001] transform-set trans
# Configure the inbound and outbound SPIs for ESP.
[DeviceA-ipsec-profile-manual-profile001] sa spi outbound esp 123456
[DeviceA-ipsec-profile-manual-profile001] sa spi inbound esp 123456
# Configure the inbound and outbound SA keys for ESP.
[DeviceA-ipsec-profile-manual-profile001] sa string-key outbound esp simple abcdefg
[DeviceA-ipsec-profile-manual-profile001] sa string-key inbound esp simple abcdefg
[DeviceA-ipsec-profile-manual-profile001] quit
On Device B:
# Create an IPsec transform set named trans .
[DeviceB] ipsec transform-set trans
# Specify the encapsulation mode as transport .
[DeviceB-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[DeviceB-ipsec-transform-set-trans] protocol esp
[DeviceB-ipsec-transform-set-trans] esp encryption-algorithm aes-cbc-128
[DeviceB-ipsec-transform-set-trans] esp authentication-algorithm sha1
[DeviceB-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile001 .
[DeviceB] ipsec profile profile001 manual
# Use IPsec transform set trans .
[DeviceB-ipsec-profile-manual-profile001] transform-set trans
# Configure the inbound and outbound SPIs for ESP.
[DeviceB-ipsec-profile-manual-profile001] sa spi outbound esp 123456
[DeviceB-ipsec-profile-manual-profile001] sa spi inbound esp 123456
# Configure the inbound and outbound SA keys for ESP.
[DeviceB-ipsec-profile-manual-profile001] sa string-key outbound esp simple abcdefg
[DeviceB-ipsec-profile-manual-profile001] sa string-key inbound esp simple abcdefg
[DeviceB-ipsec-profile-manual-profile001] quit
# Create a manual IPsec profile named profile002 .
[DeviceB] ipsec profile profile002 manual
# Use IPsec transform set trans .
[DeviceB-ipsec-profile-manual-profile002] transform-set trans
573
# Configure the inbound and outbound SPIs for ESP.
[DeviceB-ipsec-profile-manual-profile002] sa spi outbound esp 256
[DeviceB-ipsec-profile-manual-profile002] sa spi inbound esp 256
# Configure the inbound and outbound SA keys for ESP.
[DeviceB-ipsec-profile-manual-profile002] sa string-key outbound esp simple byebye
[DeviceB-ipsec-profile-manual-profile001] sa string-key inbound esp simple byebye
[DeviceB-ipsec-profile-manual-profile001] quit
On Device C:
# Create an IPsec transform set named trans .
[DeviceC] ipsec transform-set trans
# Specify the encapsulation mode as transport .
[DeviceC-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[DeviceC-ipsec-transform-set-trans] protocol esp
[DeviceC-ipsec-transform-set-trans] esp encryption-algorithm aes-cbc-128
[DeviceC-ipsec-transform-set-trans] esp authentication-algorithm sha1
[DeviceC-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile002 .
[DeviceC] ipsec profile profile002 manual
# Use IPsec transform set trans .
[DeviceC-ipsec-profile-manual-profile002] transform-set trans
# Configure the inbound and outbound SPIs for ESP.
[DeviceC-ipsec-profile-manual-profile002] sa spi outbound esp 256
[DeviceC-ipsec-profile-manual-profile002] sa spi inbound esp 256
# Configure the inbound and outbound SA keys for ESP.
[DeviceC-ipsec-profile-manual-profile002] sa string-key outbound esp simple byebye
[DeviceC-ipsec-profile-manual-profile001] sa string-key inbound esp simple byebye
[DeviceC-ipsec-profile-manual-profile001] quit
4. Apply the IPsec profiles to areas:
# Configure Device A.
[DeviceA] ospfv3 1
[DeviceA-ospfv3-1] area 1
[DeviceA-ospfv3-1-area-0.0.0.1] enable ipsec-profile profile001
[DeviceA-ospfv3-1-area-0.0.0.1] quit
[DeviceA-ospfv3-1] quit
# Configure Device B.
[DeviceB] ospfv3 1
[DeviceB-ospfv3-1] area 0
[DeviceB-ospfv3-1-area-0.0.0.0] enable ipsec-profile profile002
[DeviceB-ospfv3-1-area-0.0.0.0] quit
[DeviceB-ospfv3-1] area 1
[DeviceB-ospfv3-1-area-0.0.0.1] enable ipsec-profile profile001
[DeviceB-ospfv3-1-area-0.0.0.1] quit
[DeviceB-ospfv3-1] quit
# Configure Device C.
574
[DeviceC] ospfv3 1
[DeviceC-ospfv3-1] area 0
[DeviceC-ospfv3-1-area-0.0.0.0] enable ipsec-profile profile002
[DeviceC-ospfv3-1-area-0.0.0.0] quit
[DeviceC-ospfv3-1] quit
Verifying the configuration
# Verify that OSPFv3 packets between Devices A, B, and C are protected by IPsec. (Details not shown.)
575
Configuring IPv6 PBR
About IPv6 PBR
IPv6 policy-based routing (PBR) uses user-defined policies to route IPv6 packets. A policy can specify parameters for packets that match specific criteria such as ACLs. The parameters include the next hop, output interface, default next hop, and default output interface.
IPv6 packet forwarding process
When the device receives an IPv6 packet, the device searches the IPv6 PBR policy for a matching node to forward that packet.
•
If a matching node is found and its match mode is permit , the device performs the following operations: a. Uses the output interfaces or next hops specified on the node to forward the packet. b. Searches the routing table for a route (except the default route) to forward the packet if one of the following conditions exists:
−
No output interfaces or next hops are specified on the node.
−
Forwarding failed based on the output interfaces or next hops. c. Uses the default next hops or default output interfaces specified on the node to forward the packet if one of the following conditions exists:
−
No matching route was found in the routing table.
−
The routing table-based forwarding failed. d. Uses the default route to forward the packet if one of the following conditions exists:
−
No default next hops or default output interfaces are specified on the node.
−
The forwarding failed based on the default next hops or default output interfaces.
•
The device performs routing table lookup to forward the packet in either of the following conditions:
No matching node is found.
A matching node is found, but its match mode is deny .
IPv6 PBR types
IPv6 PBR includes the following types:
•
Local PBR —Guides the forwarding of locally generated packets, such as the ICMP packets generated by using the ping command.
•
Interface PBR —Guides the forwarding of packets received on an interface only.
Policy
An IPv6 policy includes match criteria and actions to be taken on the matching packets. A policy can have one or multiple nodes as follows:
•
Each node is identified by a node number. A smaller node number has a higher priority.
•
A node contains if-match and apply clauses. An if-match clause specifies a match criterion, and an apply clause specifies an action.
576
•
A node has a match mode of permit or deny .
An IPv6 policy compares packets with nodes in ascending order of node numbers. If a packet matches the criteria on a node, it is processed by the action on the node. Otherwise, it goes to the next node for a match. If the packet does not match the criteria on any node, the device performs a routing table lookup for the packet.
Relationship between if-match clauses
Only the if-match acl clause is supported. On a node, you can specify only one if-match acl clause.
Relationship between apply clauses
You can specify multiple apply clauses for a node, but some of them might not be executed. For more information about the relationship between the apply
clauses, see " Configuring actions for an
Relationship between the match mode and clauses on the node
Does a packet match all the if-match clauses on the node?
Yes
Match mode
In permit mode
•
If the node contains apply clauses, IPv6 PBR executes the apply clauses on the node.
If IPv6 PBR-based forwarding succeeds, IPv6
PBR does not compare the packet with the next node.
If IPv6 PBR-based forwarding fails, IPv6 PBR does not compare the packet with the next node.
•
If the node does not contain apply clauses, the device performs a routing table lookup for the packet.
In deny mode
The device performs a routing table lookup for the packet.
No
IPv6 PBR compares the packet with the next node.
IPv6 PBR compares the packet with the next node.
NOTE:
A node that has no if-match clauses matches any packet.
IPv6 PBR and Track
IPv6 PBR can work with the Track feature to dynamically adapt the availability status of an apply clause to the link status of a tracked object. The tracked object can be a next hop, output interface, default next hop, or default output interface.
•
When the track entry associated with an object changes to Negative , the apply clause is invalid.
•
When the track entry changes to Positive or NotReady , the apply clause is valid.
For more information about Track-IPv6 PBR collaboration, see High Availability Configuration Guide .
577
Restrictions and guidelines: IPv6 PBR configuration
If a packet destined for the local device matches an IPv6 PBR policy, IPv6 PBR will execute the apply clauses in the policy, including the clause for forwarding. When you configure an IPv6 PBR policy, be careful to avoid this situation.
When you deploy a new IPv6 PBR policy after a card restarts, follow these guidelines:
•
If you deploy a new IPv6 PBR policy that has a larger match range than the original IPv6 PBR policy on an interface of the same type, the following rules apply:
Traffic that matches the original IPv6 PBR policy on the current interface will suffer temporary packet loss before the new IPv6 PBR policy is deployed successfully.
After the new IPv6 PBR policy is deployed successfully, traffic forwarding on the current interface will restore to normal.
•
When you deploy a new IPv6 PBR policy on an interface of a different type, the following rules apply:
Traffic that matches the original IPv6 PBR policy on the current interface will suffer temporary packet loss before the new IPv6 PBR policy is deployed successfully.
After the new IPv6 PBR policy is deployed successfully, traffic forwarding on the current interface will restore to normal.
As a best practice to avoid traffic loss caused by PBR policy changes, configure match criteria thoroughly when you configure the first IPv6 PBR policy.
IPv6 PBR tasks at a glance
To configure IPv6 PBR, perform the following tasks:
1.
a.
b.
Setting match criteria for an IPv6 node
c.
Configuring actions for an IPv6 node
3. Specifying a policy for IPv6 PBR
Choose the following tasks as needed:
Specifying an IPv6 policy for IPv6 local PBR
Specifying an IPv6 policy for IPv6 interface PBR
4.
(Optional.) Enabling the IPv6 PBR logging feature
Configuring an IPv6 policy
Creating an IPv6 node
1. Enter system view. system-view
2. Create an IPv6 policy or policy node and enter its view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
578
3. (Optional.) Configure a description for the IPv6 policy node. description text
By default, no description is configured for an IPv6 policy node.
Setting match criteria for an IPv6 node
1. Enter system view. system-view
2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
3. Set match criteria.
Set an ACL match criterion. if-match acl { ipv6-acl-number | name ipv6-acl-name }
By default, no ACL match criterion is set.
IPv6 PBR supports both basic and advanced ACLs.
When using the ACL to match packets, IPv6 PBR ignores the action ( permit or deny ) and time range settings in the ACL.
Configuring actions for an IPv6 node
About this task
The apply clauses allow you to specify actions to take on matching packets on a node.
The following apply clauses determine the packet forwarding paths in a descending order:
• apply next-hop
• apply output-interface
• apply default-next-hop
• apply default-output-interface
IPv6 PBR supports the apply
Table 30 Apply clauses supported in IPv6 PBR
Clause apply precedence apply output-interface and apply next-hop apply default-next-hop and apply default-output-interface
Meaning
Sets an IP precedence.
Sets output interfaces and next hops.
Sets default next hops and default output interface
Remarks
This clause is always executed.
If both clauses are configured, only the apply next-hop clause is executed.
If both clauses are configured, only the apply default-next-hop clause is executed.
The clauses take effect only in the following cases:
•
No output interfaces or next hops are set or the output interfaces and next hops are invalid.
•
The packet does not match any route in the routing table.
579
Clause apply statistics
Meaning
Counts successful matches and matching bytes on the IPv6 policy node.
Remarks
To include the number of successful matches and matching bytes on an IPv6 policy node in the statistics displayed by a display command, execute this command.
This clause is always executed for matching packets.
Restrictions and guidelines for action configuration
IPv6 PBR periodically performs a lookup in the FIB table to determine the availability of a next hop or default next hop specified in an IPv6 PBR policy. If a route change occurs to the next hop, IPv6 PBR might not update the route immediately. This results in a temporary communication interruption.
Setting an IP preference
1. Enter system view. system-view
2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
3. Set an IP precedence. apply precedence { type | value }
By default, no IP precedence is specified.
Configuring actions for a node
1. Enter system view. system-view
2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
3. Configure actions for a node.
Set next hops for permitted IPv6 packets.
apply next-hop [ vpn-instance vpn-instance-name ] { ipv6-address
[ direct ] [ track track-entry-number ] } &<1-2>
By default, no next hops are specified.
You can specify multiple next hops for backup in one command line or by executing this command multiple times. You can specify a maximum of two next hops for a node.
Set output interfaces. apply output-interface { interface-type interface-number [ track track-entry-number ] }
By default, no output interfaces are specified.
As a best practice, do not specify the interface of a VXLAN tunnel automatically created by
EVPN for this command.
Set default next hops. apply default-next-hop [ vpn-instance vpn-instance-name | inbound-vpn ] { ipv6-address [ direct ] [ track track-entry-number ] }
&<1-2>
By default, no default next hops are specified.
You can specify multiple default next hops for backup in one command line or by executing this command multiple times. You can specify a maximum of two default next hops for a node.
580
Set default output interfaces. apply default-output-interface { interface-type interface-number
[ track track-entry-number ] }
By default, no default output interfaces are specified.
As a best practice, do not specify the interface of a VXLAN tunnel automatically created by
EVPN for this command.
Collecting statistics
1. Enter system view. system-view
2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
3. Count successful matches and matching bytes on the IPv6 policy node. apply statistics
Match counting is disabled on an IPv6 policy node.
After configuring this command, you cannot specify the share-mode keyword when applying the IPv6 policy to an interface for IPv6 interface PBR.
Specifying a policy for IPv6 PBR
Specifying an IPv6 policy for IPv6 local PBR
About this task
Perform this task to specify an IPv6 policy for IPv6 local PBR to guide the forwarding of locally generated packets.
Restrictions and guidelines
You can specify only one policy for IPv6 local PBR and must make sure the specified policy already exists. Before you apply a new policy, you must first remove the current policy.
IPv6 local PBR might affect local services, such as ping and Telnet. When you use IPv6 local PBR, make sure you fully understand its impact on local services of the device.
Procedure
1. Enter system view. system-view
2. Specify an IPv6 policy for IPv6 local PBR. ipv6 local policy-based-route policy-name
By default, IPv6 local PBR is not enabled.
Specifying an IPv6 policy for IPv6 interface PBR
About this task
Perform this task to apply an IPv6 policy to an interface to guide the forwarding of packets received on the interface only.
To apply an IPv6 policy to multiple VLAN interfaces at the same time, you can use the ipv6 policy-based-route apply command. Using this command simplifies configuration and saves device resources.
581
Restrictions and guidelines
You can apply only one policy to an interface and must make sure the specified policy already exists.
Before you apply a new policy, you must first remove the current policy from the interface.
You can apply a policy to multiple interfaces.
Procedure
1. Enter system view. system-view
2. Enter interface view. interface interface-type interface-number
3. Specify an IPv6 policy for IPv6 interface PBR. ipv6 policy-based-route policy-name [ share-mode ]
By default, no IPv6 policy is applied to the interface.
You cannot specify the share-mode keyword for the command if you have configured the apply statistics command for the IPv6 policy.
Enabling the IPv6 PBR logging feature
About this task
The IPv6 PBR logging feature helps the administrator locate and fix faults. The feature logs IPv6
PBR events and sends the logs to the information center. The information center processes the logs according to output rules. For more information about the information center, see System
Management Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enable the IPv6 PBR logging feature. ipv6 policy-based-route-log enable
By default, the IPv6 PBR logging feature is disabled.
Verifying and maintaining IPv6 PBR
Verifying IPv6 PBR policy configuration
To display IPv6 PBR policy information, execute the following command in any view: display ipv6 policy-based-route [ policy policy-name ]
Displaying IPv6 PBR configuration and statistics
Perform display tasks in any view.
•
Display IPv6 PBR configuration. display ipv6 policy-based-route setup
•
Display IPv6 local PBR configuration and statistics. display ipv6 policy-based-route local [ slot slot-number ]
•
Display IPv6 interface PBR configuration and statistics.
582
display ipv6 policy-based-route interface interface-type interface-number [ slot slot-number ]
Clearing IPv6 PBR statistics
To clear IPv6 PBR statistics, execute the following command in user view: reset ipv6 policy-based-route statistics [ policy policy-name ]
IPv6 PBR configuration examples
Example: Configuring packet type-based IPv6 local PBR
Network configuration
As shown in Figure 125 , Device B and Device C are connected through Device A. Device B and
Device C do not have a route to reach each other.
Configure IPv6 PBR on Device A to forward all TCP packets to the next hop 1::2 (Device B).
Figure 125 Network diagram
Device B
HGE1/0/1
1::1/64
HGE1/0/1
1::2/64
Device A
HGE1/0/2
2::1/64
HGE1/0/2
2::2/64
Device C
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure Device A:
# Configure the IPv6 addresses of HundredGigE 1/0/1 and HundredGigE 1/0/2.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ipv6 address 1::1 64
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ipv6 address 2::1 64
[DeviceA-HundredGigE1/0/2] quit
# Configure ACL 3001 to match TCP packets.
[DeviceA] acl ipv6 advanced 3001
[DeviceA-acl-ipv6-adv-3001] rule permit tcp
[DeviceA-acl-ipv6-adv-3001] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1::2.
[DeviceA] ipv6 policy-based-route aaa permit node 5
[DeviceA-pbr6-aaa-5] if-match acl 3001
[DeviceA-pbr6-aaa-5] apply next-hop 1::2
583
[DeviceA-pbr6-aaa-5] quit
# Configure IPv6 local PBR by applying policy aaa to Device A.
[DeviceA] ipv6 local policy-based-route aaa
2. On Device B, configure the IPv6 address of HundredGigE 1/0/1.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ipv6 address 1::2 64
3. On Device C, configure the IPv6 address of HundredGigE 1/0/2.
<DeviceC> system-view
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] ipv6 address 2::2 64
Verifying the configuration
1. Perform telnet operations to verify that IPv6 local PBR on Device A operates as configured to forward the matching TCP packets to the next hop 1::2 (Device B), as follows:
# Verify that you can telnet to Device B from Device A successfully. (Details not shown.)
# Verify that you cannot telnet to Device C from Device A. (Details not shown.)
2. Verify that Device A forwards packets other than TCP packets through HundredGigE 1/0/2. For example, verify that you can ping Device C from Device A. (Details not shown.)
Example: Configuring packet type-based IPv6 interface PBR
Network configuration
As shown in Figure 126 , Device B and Device C do not have a route to reach each other.
Configure IPv6 PBR on Device A to forward all TCP packets received on HundredGigE 1/0/1 to the next hop 1::2 (Device B).
Figure 126 Network diagram
Device B Device C
HGE1/0/2
1::2/64
HGE1/0/3
2::2/64
HGE1/0/2
1::1/64
HGE1/0/3
2::1/64
Device A
HGE1/0/1
10::2/64
Subnet
10::1/64
Host A
10::3/64
Gateway: 10::2/64
Host B
584
Procedure
IMPORTANT:
By default, interfaces on the devices are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure Device A:
# Configure RIPng.
<DeviceA> system-view
[DeviceA] ripng 1
[DeviceA-ripng-1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ipv6 address 1::1 64
[DeviceA-HundredGigE1/0/2] ripng 1 enable
[DeviceA-HundredGigE1/0/2] quit
[DeviceA] interface hundredgige 1/0/3
[DeviceA-HundredGigE1/0/3] ipv6 address 2::1 64
[DeviceA-HundredGigE1/0/3] ripng 1 enable
[DeviceA-HundredGigE1/0/3] quit
# Configure ACL 3001 to match TCP packets.
[DeviceA] acl ipv6 advanced 3001
[DeviceA-acl-ipv6-adv-3001] rule permit tcp
[DeviceA-acl-ipv6-adv-3001] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1::2.
[DeviceA] ipv6 policy-based-route aaa permit node 5
[DeviceA-pbr6-aaa-5] if-match acl 3001
[DeviceA-pbr6-aaa-5] apply next-hop 1::2
[DeviceA-pbr6-aaa-5] quit
# Configure IPv6 interface PBR by applying policy aaa to HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ipv6 address 10::2 64
[DeviceA-HundredGigE1/0/1] undo ipv6 nd ra halt
[DeviceA-HundredGigE1/0/1] ripng 1 enable
[DeviceA-HundredGigE1/0/1] ipv6 policy-based-route aaa
[DeviceA-HundredGigE1/0/1] quit
2. Configure RIPng on Device B.
<DeviceB> system-view
[DeviceB] ripng 1
[DeviceB-ripng-1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] ipv6 address 1::2 64
[DeviceB-HundredGigE1/0/2] ripng 1 enable
[DeviceB-HundredGigE1/0/2] quit
3. Configure RIPng on Device C.
<DeviceC> system-view
[DeviceC] ripng 1
[DeviceC-ripng-1] quit
[DeviceC] interface hundredgige 1/0/3
585
[DeviceC-HundredGigE1/0/3] ipv6 address 2::2 64
[DeviceC-HundredGigE1/0/3] ripng 1 enable
[DeviceC-HundredGigE1/0/3] quit
Verifying the configuration
1. Enable IPv6 and configure the IPv6 address 10::3 for Host A.
C:\>ipv6 install
Installing...
Succeeded.
C:\>ipv6 adu 4/10::3
2. Perform telnet operations to verify that IPv6 interface PBR on Device A operates as configured to forward the matching TCP packets to the next hop 1::2 (Device B), as follows:
# Verify that you can telnet to Device B from Host A successfully. (Details not shown.)
# Verify that you cannot telnet to Device C from Host A. (Details not shown.)
3. Verify that Device A forwards packets other than TCP packets through HundredGigE 1/0/3. For example, verify that you can ping Device C from Host A. (Details not shown.)
586
Configuring routing policies
About routing policies
Routing policies control routing paths by filtering and modifying routing information.
Routing policies can filter advertised, received, and redistributed routes, and modify attributes for specific routes.
Implementation of a routing policy
To configure a routing policy:
1. Configure filters based on route attributes.
2. Create a routing policy and apply filters to the routing policy.
Filters
Routing policies can use the following filters to match routes.
ACL
An ACL can match the destination or next hop of routes.
For more information about ACLs, see ACL and QoS Configuration Guide .
IP prefix list
An IP prefix list matches the destination address of routes.
An IP prefix list can contain multiple items that specify prefix ranges. Each destination IP address prefix of a route is compared with these items in ascending order of their index numbers. A prefix matches the IP prefix list if it matches one item in the list.
AS path list
An AS path list matches the AS_PATH attribute of BGP routes. The AS_PATH attribute identifies the
ASs through which a route has passed.
For more information about AS path lists, see basic BGP configuration.
Community list
A community list matches the COMMUNITY attribute of BGP routes. The COMMUNITY attribute identifies the community of BGP routes.
For more information about community lists, see basic BGP configuration.
RD list
A route distinguisher (RD) list matches the RD of routes.
An RD list is identified by an RD list number and can contain multiple items that specify RD ranges.
Each item is identified by an index number. The RD of a route is compared with these items in ascending order of their index numbers. An RD matches the RD list if it matches one item in the list.
Routing policy
A routing policy can contain multiple nodes, which are in a logical OR relationship. A node with a smaller number is matched first. A route matches the routing policy if it matches one node (except the node configured with the continue clause) in the routing policy.
587
Each node has a match mode of permit or deny .
• permit —Specifies the permit match mode for a routing policy node. If a route meets all the if-match clauses of the node, it is handled by the apply clauses of the node. The route is not compared with the next node unless the continue clause is configured. If a route does not meet all the if-match clauses of the node, it is compared with the next node.
• deny —Specifies the deny match mode for a routing policy node. The apply and continue clauses of a deny node are never executed. If a route meets all the if-match clauses of the node, it is denied without being compared with the next node. If a route does not meet all the if-match clauses of the node, it is compared with the next node.
A node can contain a set of if-match , apply , and continue clauses.
• if-match clauses —Specify the match criteria that match the attributes of routes. The if-match clauses are in a logical AND relationship. A route must meet all the if-match clauses to match the node.
• apply clauses —Specify the actions to be taken on permitted routes, such as modifying a route attribute.
• continue clause —Specifies the next node. A route that matches the current node (permit node) must match the specified next node in the same routing policy. The continue clause combines the if-match and apply clauses of the two nodes to improve flexibility of the routing policy. After you configure a continue clause, a route can pass the routing policy even if it does not match the specified next node. To reject such a route, add a deny node without clauses.
Follow these guidelines when you configure if-match , apply , and continue clauses:
•
If you only want to filter routes, do not configure apply clauses.
•
If you do not configure any if-match clauses for a permit node, the node will permit all routes.
•
Configure a permit node containing no if-match or apply clauses following multiple deny nodes to allow unmatched routes to pass.
Routing policy tasks at a glance
To configure a routing policy, perform the following tasks:
1. (Optional.) Configure filters:
Configuring an IPv4 prefix list
Configuring an IPv6 prefix list
2.
a.
b.
c.
d.
Configuring the continue clause
588
Configuring an IPv4 prefix list
Restrictions and guidelines
If all the items are set to deny mode, no routes can pass the IPv4 prefix list. To permit unmatched
IPv4 routes, you must configure the permit 0.0.0.0 0 less-equal 32 item following multiple deny items.
Procedure
1. Enter system view. system-view
2. Configure an IPv4 prefix list. ip prefix-list prefix-list-name [ index index-number ] { deny | permit } ip-address mask-length [ greater-equal min-mask-length ] [ less-equal max-mask-length ]
Configuring an IPv6 prefix list
Restrictions and guidelines
If all items are set to deny mode, no routes can pass the IPv6 prefix list. To permit unmatched IPv6 routes, you must configure the permit :: 0 less-equal 128 item following multiple deny items.
Procedure
1. Enter system view. system-view
2. Configure an IPv6 prefix list.
ipv6 prefix-list prefix-list-name [ index index-number ] { deny | permit } ipv6-address { inverse inverse-prefix-length | prefix-length
[ greater-equal min-prefix-length ] [ less-equal max-prefix-length ] }
Configuring an AS path list
About this task
The AS_PATH attribute identifies the ASs through which a BGP route has passed. Figure 127 shows
the AS_PATH attribute format in a BGP routing table.
Figure 127 AS_PATH attribute
AS_PATH:(100 200) [300 400] 500 600 {700 800}
AS_CONFED_SEQUENCE
AS_SEQUENCE
AS_CONFED_SET
AS_SET
The AS_PATH attribute value is a character string containing digits, parentheses, brackets, braces, and spaces. It is a sequence of the following AS path segments:
•
AS_CONFED_SEQUENCE —Ordered set of member AS numbers in the local confederation that the UPDATE message has traversed.
•
AS_CONFED_SET —Unordered set of member AS numbers in the local confederation that the
UPDATE message has traversed.
•
AS_SEQUENCE —Ordered set of ASs a route in the UPDATE message has traversed.
589
•
AS_SET —Unordered set of ASs a route in the UPDATE message has traversed.
NOTE:
The AS_PATH attribute of a BGP route might not contain all of the four AS path segments.
An AS path list consists of regular expressions used for filtering BGP routes by their AS_PATH attributes. A regular expression can contain the special characters described in
Table 31 Special characters supported in a regular expression
Character
^
$
.
*
+ x|y
( )
[xyz]
[^xyz]
Description
Matches the beginning of a line.
Matches the end of a line.
Matches any single character.
Matches the preceding character or string zero, one, or multiple times.
Matches the preceding character or string one or multiple times.
Example
Match a local route if its AS_PATH attribute is null: ip as-path { as-path-number | as-path-name } { deny | permit } ^$
Match a route if it is originated from AS 100: ip as-path { as-path-number | as-path-name } { deny | permit } 100$
Match a route if it has passed AS 100 but is not originated or received from AS 100: ip as-path { as-path-number | as-path-name } { deny | permit } .
100.
Match a route if it has an AS_PATH attribute: ip as-path { as-path-number | as-path-name } { deny | permit } .*
Match a route if its AS_PATH attribute value contains 5 : ip as-path { as-path-number | as-path-name } { deny | permit } 5+
Matches the preceding or succeeding string.
Matches the string in the parentheses, usually used together with the plus sign (+) or asterisk sign (*).
Match a route if it is originated from AS 100 or AS
200: ip as-path { as-path-number | as-path-name } { deny | permit }
100$|200$
Match a route if its AS_PATH attribute value contains 123 : ip as-path { as-path-number | as-path-name } { deny | permit }
(123)+
Matches a single character in the brackets.
Match a route if it is received from AS 10 through
AS 19: ip as-path { as-path-number | as-path-name } { deny | permit }
^1[0-9]$
Matches a single character that is not in the brackets.
Match a route if its originating AS number does not end with 2 or 4 : ip as-path { as-path-number | as-path-name } { deny | permit }
[^24]$
590
Character
{n}
{n,}
{n,m}
[a-z]
[^a-z]
_
\b
\B
\
\w
\W
Description
Matches the preceding character n times. The number n must be a nonnegative integer.
Matches the preceding character n times or more. The number n must be a nonnegative integer.
Example
Match a route if its AS_PATH attribute value contains two 5 : ip as-path { as-path-number | as-path-name } { deny | permit } 5{2}
Match a route if its AS_PATH attribute value contains two or more consecutive 5 : ip as-path { as-path-number | as-path-name } { deny | permit } 5{2,}
Matches the preceding character n to m times or more. The numbers n and m must be nonnegative integers and n cannot be greater than m .
Matches a single character within the specified range for only once.
Match a route if its AS_PATH attribute value contains one or more consecutive 5 : ip as-path { as-path-number | as-path-name } { deny | permit }
5{1,2}
Match a route if its AS_PATH attribute value contains 0 , 1 , or 2 : ip as-path { as-path-number | as-path-name } { deny | permit } [0-2]
Matches a single character that is not in the specified range.
Match a route if its AS_PATH attribute value contains digits other than 0 , 1 , or 2 : ip as-path { as-path-number | as-path-name } { deny | permit } ^
[^0-2]$
Matches a punctuation. The expression can begin or end with
_.
Match a route if it has passed AS101 100: ip as-path { as-path-number | as-path-name } { deny | permit }
101 _ 100_
Matches a word that starts with the pattern following \b or ends with the pattern preceding \b.
Matches a word that contains the pattern but does not start or end with the pattern.
Match a route if it is originated from AS 100: ip as-path { as-path-number | as-path-name } { deny | permit }
\b100$
Match a route if its AS_PATH attribute value starts with 1 : ip as-path { as-path-number | as-path-name } { deny | permit } ^1 \B
Escape character. If a special character listed in this table follows \, the specific meaning of the character is removed.
N/A
Same as [ A-Za-z0-9_ ] , matches a digit, letter, or underscore.
Match a route if its AS_PATH attribute value contains double digits: ip as-path { as-path-number | as-path-name } \w{2}
Same as [ ^A-Za-z0-9_ ] , matches a character that is not a digit, letter, or underscore.
N/A
591
Character
\index
Description
Matches the specified string in the parentheses followed by \ twice.
Each string in the parentheses is numbered from 1 in order. The index argument represents the sequence number of the string you want to match. If the parentheses contain n strings, you can specify the sequence number of the string in the range of 1 to n .
Example
Match a route if its AS_PATH attribute value contains two consecutive 1 : ip as-path { as-path-number | as-path-name } (1)\1
NOTE:
The regular expressions shown in Table 34
are used for illustration only. Other regular expressions might be available to achieve the same effect.
Restrictions and guidelines
You can configure multiple items for an AS path list that is identified by a number. The relationship between the items is logical OR. A route matches the AS path list if it matches one item in the list.
Procedure
1. Enter system view. system-view
2. Configure an AS path list. ip as-path { as-path-number | as-path-name } { deny | permit } regular-expression
Configuring a community list
About this task
You can configure multiple items for a community list that is identified by a number. The relationship between the items is logical OR. A route matches the community list if it matches one item in the list.
An advanced community list matches the community attributes of BGP routes based on the regular
expressions described in "Configuring an AS path list."
Procedure
1. Enter system view. system-view
2. Configure a community list.
Configure a basic community list. ip community-list { basic-comm-list-num | basic basic-comm-list-name } { deny | permit } [ community-number &<1-32> | aa:nn &<1-32> ] [ internet | no-advertise | no-export | no-export-subconfed ] *
Configure an advanced community list.
ip community-list { adv-comm-list-num | advanced adv-comm-list-name } { deny | permit } regular-expression
592
Configuring a tag list
About this task
You can configure multiple items for a tag list. The relationship between the items is logical OR. A route matches the tag list if it matches one item in the list.
Procedure
1. Enter system view. system-view
2. Configure a tag list. route tag-list tag-list-number [ index index-number ] { deny | permit } tag-value &<1-32>
Configuring an RD list
About this task
You can configure multiple items for an RD list that is identified by a number. The relationship between the items is logical OR. A route matches the RD list if it matches one item in the list.
Procedure
1. Enter system view. system-view
2. Configure an RD list. ip rd-list rd-list-number [ index index-number ] { deny | permit } route-distinguisher &<1-10>
Configuring a routing policy
Creating a routing policy
About this task
A routing policy must have a minimum of one permit node. If all the nodes are in deny mode, no routes can pass the routing policy.
Procedure
1. Enter system view. system-view
2. Create a routing policy and a node, and enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number
3. (Optional.) Configure a description for the routing policy node. description text
By default, no description is configured for a routing policy node.
4. (Optional.) Prevent all routes from passing a routing policy that does not exist. a. Return to system view. quit b. Prevent all routes from passing a routing policy that does not exist.
593
route-policy non-exist-deny
By default, all routes can pass a routing policy that does not exist.
Configuring if-match clauses
About this task
You can either specify no if-match clauses or multiple if-match clauses for a routing policy node. If no if-match clause is specified for a permit node, all routes can pass the node. If no if-match clause is specified for a deny node, no routes can pass the node.
Restrictions and guidelines
When you configure if-match clauses, follow these restrictions and guidelines:
•
The if-match clauses of a routing policy node have a logical AND relationship. A route must meet all if-match clauses before it can be executed by the apply clauses of the node. If an if-match command exceeds the maximum length, multiple if-match clauses of the same type are generated. These clauses have a logical OR relationship. A route only needs to meet one of them.
•
All IPv4 routes match a node if the if-match clauses of the node use only IPv6 ACLs. All IPv6 routes match a node if the if-match clauses of the node use only IPv4 ACLs.
•
If the ACL used by an if-match clause does not exist, the clause is always matched. If no rules of the specified ACL are matched or the matched rules are inactive, the clause is not matched.
•
If the prefix list, community list, or extended community list used by an if-match clause does not exist, the clause is always matched. If no rules of the specified prefix list, community list, or extended community list are matched, the clause is not matched.
Procedure
1. Enter system view. system-view
2. Enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number
3. Match routes whose destination, next hop, or source address matches an ACL or prefix list.
IPv4: if-match ip { address | next-hop | route-source } { acl { ipv4-acl-number
| name ipv4-acl-name } | prefix-list prefix-list-name }
IPv6: if-match ipv6 { address | next-hop | route-source } { acl
{ ipv6-acl-number | name ipv6-acl-name } | prefix-list prefix-list-name }
By default, no ACL or prefix list match criterion is configured.
The ACL specified in an if-match clause must be a non-VPN ACL.
4. Configure BGP route match criteria.
Match BGP routes whose AS_PATH attribute matches a specified AS path list. if-match as-path { as-path-number &<1-32> | as-path-name }
Match BGP routes whose COMMUNITY attribute matches a specified community list. if-match community { { basic-community-list-number | name comm-list-name } [ whole-match ] | adv-community-list-number }&<1-32>
594
Match BGP routes whose extended community attribute matches a specified extended community list. if-match extcommunity { ext-comm-list-number | ext-comm-list-name }&<1-32>
Match BGP routes having the specified local preference. if-match local-preference preference
Match BGP routes with the specified RPKI validation state. if-match rpki { invalid | not-found | valid }
By default, no BGP route match criteria are configured.
5. Configure route match criteria.
Match routes having the specified cost.
if-match cost cost-value
Match routes having the specified output interface. if-match interface { interface-type interface-number }&<1-16>
This command is not supported by BGP.
Match routes having the specified route type. if-match route-type { bgp-evpn-imet | bgp-evpn-ip-prefix | bgp-evpn-mac-ip | external-type1 | external-type1or2 | external-type2 | internal | is-is-level-1 | is-is-level-2 | nssa-external-type1 | nssa-external-type1or2 | nssa-external-type2 } *
Match IGP routes having the specified tag value.
if-match tag tag-value
Match IGP routes whose tag matches the specified tag list. if-match tag-list tag-list-number
By default, no route match criteria are configured.
6. Match routes with the specified L3VNI.
if-match l3-vni vxlan-id
By default, no L3VNI match criterion is configured.
7. Match routes whose RD matches the specified RD list. if-match rd-list rd-list-number
By default, no RD match criterion is configured.
8. Match routes by using a routing policy. if-match route-policy route-policy-name
By default, no routing policy is specified to match routes.
9. Match IPv6 route prefixes of the specified length whose last bit is an odd or even number.
Match IPv6 route prefixes of the specified length whose last bit is an odd number. if-match ipv6 odd-prefix-length prefix-length-number
By default, no match criterion is configured to match the length and last bit of IPv6 route prefixes.
Match IPv6 route prefixes of the specified length whose last bit is an even number. if-match ipv6 even-prefix-length prefix-length-number
By default, no match criterion is configured to match the length and last bit of IPv6 route prefixes.
595
Configuring apply clauses
1. Enter system view. system-view
2. Enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number
3. Configure BGP route attributes.
Set the AIGP attribute for BGP routes. apply aigp { cost-value | igp-cost }
Set the AS_PATH attribute for BGP routes.
apply as-path as-number &<1-32> [ replace ]
Delete the specified COMMUNITY attribute for BGP routes. apply comm-list { comm-list-number | comm-list-name } delete
By default, no COMMUNITY attribute is deleted for BGP routes.
Set the specified COMMUNITY attribute for BGP routes. apply community { none | additive | { community-number &<1-32> | aa:nn &<1-32> | internet | no-advertise | no-export | no-export-subconfed } * [ additive ] }
Set the extended community attribute for BGP routes. apply extcommunity { bandwidth link-bandwidth-value | rt route-target }&<1-32> [ additive ]
Set the color extended community attribute for BGP routes. apply extcommunity color color [ additive ]
Set the SoO extended community attribute for BGP routes. apply extcommunity soo site-of-origin &<1-32> [ additive ]
Set a local preference for BGP routes. apply local-preference preference
Set the ORIGIN attribute for BGP routes. apply origin { egp as-number | igp | incomplete }
Set a preferred value for BGP routes. apply preferred-value preferred-value
Set a traffic index for BGP routes. apply traffic-index { value | clear }
Set a DSCP value for BGP routes.
apply dscp dscp-value
Set a VPN peer ID for BGP routes. apply vpn-peer-id peer-id
For information about VPN peers, see MPLS L3VPN configuration in MPLS Configuration
Guide .
By default, no BGP route attributes are configured.
4. Configure the route cost and cost type.
Set a cost for routes. apply cost [ + | - ] cost-value
By default, no cost is set for routes.
596
Set a cost type for routes. apply cost-type { external | internal | type-1 | type 2 }
By default, no cost type is set for routes.
5. Set the next hop for routes.
IPv4: apply ip-address next-hop ip-address [ public | vpn-instance vpn-instance-name ]
IPv6: apply ipv6 next-hop ipv6-address
By default, no next hop is set for routes.
The configuration does not apply to redistributed routes.
6. Configure route priorities.
Set an IP precedence for matching routes. apply ip-precedence { value | clear }
By default, no IP precedence is set.
Set a preference. apply preference preference
By default, no preference is set.
Set a prefix priority. apply prefix-priority { critical | high | medium }
By default, the prefix priority is low.
7. Redistribute routes to the specified IS-IS level. apply isis { level-1 | level-1-2 | level-2 }
By default, routes are not redistributed into the specified IS-IS level.
8. Set a label index value or SID value.
Set a label index value. apply label-index index-value
By default, no label index value is set.
Set an SID value.
apply label-value label-value
By default, no SID value is set.
9. Set a local QoS ID for matching routes. apply qos-local-id { local-id-value | clear }
By default, no local QoS ID is set.
10. Set a tag value for IGP routes.
apply tag tag-value
By default, no tag value is set for IGP routes.
11. Set an MPLS EXP value for matching routes. apply mpls-exp mpls-exp-value
By default, no MPLS EXP value is set.
12. Set a backup link for fast reroute (FRR).
IPv4: apply fast-reroute { backup-interface interface-type interface-number
[ backup-nexthop ip-address ] | backup-nexthop ip-address }
597
IPv6: apply ipv6 fast-reroute { backup-interface interface-type interface-number [ backup-nexthop ipv6-address ] | backup-nexthop ipv6-address }
By default, no backup link is set for FRR.
13. Set an L3VNI.
apply l3-vni vxlan-id
By default, no L3VNI is set.
Configuring the continue clause
Restrictions and guidelines
When you configure the continue clause to combine multiple nodes, follow these restrictions and guidelines:
•
If you configure an apply clause that sets different attribute values on all the nodes, the apply clause of the node configured most recently takes effect.
•
If you configure the following apply clauses on all the nodes, the apply clause of each node takes effect:
apply as-path without the replace keyword. apply cost with the + or – keyword.
apply community with the additive keyword.
apply extcommunity with the additive keyword.
•
The apply comm-list delete clause configured on the current node cannot delete the community attributes set by the apply community clauses of the preceding nodes.
Procedure
1. Enter system view. system-view
2. Enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number
3. Specify the next node to be matched. continue [ node-number ]
By default, no continue clause is configured.
The specified next node must have a larger number than the current node.
Verifying and maintaining routing policies
Verifying routing policy configuration
Perform display tasks in any view.
•
Display BGP community list information. display ip community-list [ basic-community-list-number | adv-community-list-number | name comm-list-name ]
•
Display tag list information. display route tag-list [ tag-list-number ]
•
Display RD list information.
598
display ip rd-list [ rd-list-number ]
•
Display routing policy information. display route-policy [ name route-policy-name ]
Displaying and clearing BGP AS path list statistics
Displaying BGP AS path list statistics
To display BGP AS path list statistics, execute the following command in any view: display ip as-path [ as-path-number | as-path-name ]
Clearing BGP AS path list statistics
To clear BGP AS path list statistics, execute the following command in user view: reset ip as-path [ as-path-number | as-path-name ]
Displaying and clearing IP prefix list statistics
Displaying IP prefix list statistics
Perform display tasks in any view.
•
Display IPv4 prefix list statistics. display ip prefix-list [ name prefix-list-name ]
•
Display IPv6 prefix list statistics. display ipv6 prefix-list [ name prefix-list-name ]
Clearing IP prefix list statistics
Perform clear tasks in user view.
•
Clear IPv4 prefix list statistics. reset ip prefix-list [ prefix-list-name ]
•
Clear IPv6 prefix list statistics. reset ipv6 prefix-list [ prefix-list-name ]
Routing policy configuration examples
Example: Configuring a routing policy for IPv4 route redistribution
Network configuration
As shown in Figure 128 , Device B exchanges routing information with Device A by using OSPF and
with Device C by using IS-IS.
On Device B, enable route redistribution from IS-IS to OSPF. Use a routing policy to set the cost of route 172.17.1.0/24 to 100 and the tag of route 172.17.2.0/24 to 20.
599
Figure 128 Network diagram
OSPF
HGE1/0/1
192.168.1.2/24
HGE1/0/2
Device B
192.168.2.2/24
IS-IS
HGE1/0/1
172.17.1.1/24
HGE1/0/1
192.168.1.1/24
HGE1/0/4
192.168.2.1/24 HGE1/0/2
172.17.2.1/24
Device A Device C
HGE1/0/3
172.17.3.1/24
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IS-IS:
# Configure Device C.
<DeviceC> system-view
[DeviceC] isis
[DeviceC-isis-1] is-level level-2
[DeviceC-isis-1] network-entity 10.0000.0000.0001.00
[DeviceC-isis-1] quit
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] isis enable
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] isis enable
[DeviceC-HundredGigE1/0/2] quit
[DeviceC] interface hundredgige 1/0/3
[DeviceC-HundredGigE1/0/3] isis enable
[DeviceC-HundredGigE1/0/3] quit
[DeviceC] interface hundredgige 1/0/4
[DeviceC-HundredGigE1/0/4] isis enable
[DeviceC-HundredGigE1/0/4] quit
# Configure Device B.
<DeviceB> system-view
[DeviceB] isis
[DeviceB-isis-1] is-level level-2
[DeviceB-isis-1] network-entity 10.0000.0000.0002.00
[DeviceB-isis-1] quit
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] isis enable
600
[DeviceB-HundredGigE1/0/2] quit
3. Configure OSPF and route redistribution:
# Configure OSPF on Device A.
<DeviceA> system-view
[DeviceA] ospf
[DeviceA-ospf-1] area 0
[DeviceA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[DeviceA-ospf-1-area-0.0.0.0] quit
[DeviceA-ospf-1] quit
# On Device B, configure OSPF and enable route redistribution from IS-IS to OSPF.
[DeviceB] ospf
[DeviceB-ospf-1] area 0
[DeviceB-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[DeviceB-ospf-1-area-0.0.0.0] quit
[DeviceB-ospf-1] import-route isis 1
[DeviceB-ospf-1] quit
# Display the OSPF routing table on Device A to view the redistributed routes.
[DeviceA] display ospf routing
OSPF Process 1 with Router ID 192.168.1.1
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
192.168.1.0/24 1 Transit 192.168.1.1 192.168.1.1 0.0.0.0
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
172.17.1.0/24 1 Type2 1 192.168.1.2 192.168.2.2
172.17.2.0/24 1 Type2 1 192.168.1.2 192.168.2.2
172.17.3.0/24 1 Type2 1 192.168.1.2 192.168.2.2
Total Nets: 4
Intra Area: 1 Inter Area: 0 ASE: 3 NSSA: 0
4. Configure filtering lists on Device B:
# Configure IPv4 basic ACL 2002 to permit route 172.17.2.0/24.
[DeviceB] acl basic 2002
[DeviceB-acl-ipv4-basic-2002] rule permit source 172.17.2.0 0.0.0.255
[DeviceB-acl-ipv4-basic-2002] quit
# Configure IP prefix list prefix-a to permit route 172.17.1.0/24.
[DeviceB] ip prefix-list prefix-a index 10 permit 172.17.1.0 24
5. Configure a routing policy on Device B.
[DeviceB] route-policy isis2ospf permit node 10
[DeviceB-route-policy-isis2ospf-10] if-match ip address prefix-list prefix-a
[DeviceB-route-policy-isis2ospf-10] apply cost 100
[DeviceB-route-policy-isis2ospf-10] quit
[DeviceB] route-policy isis2ospf permit node 20
[DeviceB-route-policy-isis2ospf-20] if-match ip address acl 2002
601
[DeviceB-route-policy-isis2ospf-20] apply tag 20
[DeviceB-route-policy-isis2ospf-20] quit
[DeviceB] route-policy isis2ospf permit node 30
[DeviceB-route-policy-isis2ospf-30] quit
6. Apply the routing policy to route redistribution on Device B:
# On Device B, enable route redistribution from IS-IS to OSPF and apply the routing policy.
[DeviceB] ospf
[DeviceB-ospf-1] import-route isis 1 route-policy isis2ospf
[DeviceB-ospf-1] quit
# Display OSPF routing table information on Device A.
[DeviceA] display ospf routing
OSPF Process 1 with Router ID 192.168.1.1
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
192.168.1.0/24 1 Transit 192.168.1.1 192.168.1.1 0.0.0.0
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
172.17.1.0/24 100 Type2 1 192.168.1.2 192.168.2.2
172.17.2.0/24 1 Type2 20 192.168.1.2 192.168.2.2
172.17.3.0/24 1 Type2 1 192.168.1.2 192.168.2.2
Total Nets: 4
Intra Area: 1 Inter Area: 0 ASE: 3 NSSA: 0
The output shows that the cost of route 172.17.1.0/24 is 100 and the tag of route 172.17.2.0/24 is 20.
Example: Configuring a routing policy for IPv6 route redistribution
Network configuration
•
Run RIPng on Device A and Device B.
•
Configure three static routes on Device A.
•
On Device A, apply a routing policy to redistribute static routes 20::/32 and 40::/32 and deny route 30::/32.
Figure 129 Network diagram
20::/32
30::/32
40::/32
HGE1/0/2
11::1/32
HGE1/0/1
10::1/32
HGE1/0/1
10::2/32
Device A Device B
602
Procedure
NOTE:
By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.
1. Configure Device A:
# Configure IPv6 addresses for interfaces HundredGigE 1/0/1 and HundredGigE 1/0/2.
<DeviceA> system-view
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ipv6 address 10::1 32
[DeviceA-HundredGigE1/0/1] quit
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] ipv6 address 11::1 32
[DeviceA-HundredGigE1/0/2] quit
# Enable RIPng on HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] ripng 1 enable
[DeviceA-HundredGigE1/0/1] quit
# Configure three static routes with next hop 11::2, and make sure the static routes are active.
[DeviceA] ipv6 route-static 20:: 32 11::2
[DeviceA] ipv6 route-static 30:: 32 11::2
[DeviceA] ipv6 route-static 40:: 32 11::2
# Configure a routing policy.
[DeviceA] ipv6 prefix-list a index 10 permit 30:: 32
[DeviceA] route-policy static2ripng deny node 0
[DeviceA-route-policy-static2ripng-0] if-match ipv6 address prefix-list a
[DeviceA-route-policy-static2ripng-0] quit
[DeviceA] route-policy static2ripng permit node 10
[DeviceA-route-policy-static2ripng-10] quit
# Enable RIPng and apply routing policy static2ripng to filter redistributed static routes on
Device A.
[DeviceA] ripng
[DeviceA-ripng-1] import-route static route-policy static2ripng
2. Configure Device B:
# Configure the IPv6 address of HundredGigE 1/0/1.
<DeviceB> system-view
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ipv6 address 10::2 32
# Enable RIPng.
[DeviceB] ripng
[DeviceB-ripng-1] quit
# Enable RIPng on the interface.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] ripng 1 enable
[DeviceB-HundredGigE1/0/1] quit
603
Verifying the configuration
# Display the RIPng routing table on Device B.
[DeviceB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect, D – Direct
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::7D58:0:CA03:1 on HundredGigE1/0/1
Destination 20::/32,
via FE80::7D58:0:CA03:1, cost 1, tag 0, A, 8 secs
Destination 40::/32,
via FE80::7D58:0:CA03:1, cost 1, tag 0, A, 3 secs
Local route
Destination 10::/32,
via ::, cost 0, tag 0, DOF
604
Configuring DCN
About DCN
Data communication network (DCN) is built for the network management system (NMS) to implement operation, administration, and maintenance (OAM) on the network elements (NEs).
On large-scaled networks with DCN configured, the NMS remotely manages and controls all NEs through the gateway network element (GNE), which reduces operation and maintenance costs.
On the DCN network, all NEs must operate in Area 0 of OSPF process 65535.
Basic concepts
NE
A network device managed by the NMS on the DCN network.
GNE
NE table
The NE that is directly connected to the NMS. The NSM communicates with the GNE at the network layer or application layer and manages the NEs through the GNE.
Stores the NE ID-to-NE IP mappings for each NE in the DCN domain. After DCN is enabled, an NE encapsulates its NE ID and NE IP in a Type-10 Opaque LSA. It floods the LSA to synchronize the mappings with other NEs in the DCN domain.
The NE IP in the Type-10 Opaque LSA might be inconsistent with the NE's router ID when DCN is enabled on an OSPF network. Devices from other vendors will fail to identify the NE. To avoid this problem, make sure the following requirements are met:
•
Change the router ID by modifying the NE IP. Do not change the default IP address of the
DCN's loopback interface.
•
Do not associate other loopback interfaces to the DCN VPN instance.
GNE
The GNE allows the NMS to access NEs on the DCN network. The GNE provides the NE ID-to-NE
IP mappings of all NEs for the Telnet users to access the target NE remotely.
NE search
The NE search feature allows the NMS to search for all NEs that are connected to the GNE. With this feature, the GNE can report information about all NEs in its NE table and the GNE itself to the NMS.
Automatic report
The automatic report feature enables the GNE to automatically report online or offline events of NEs to the NMS.
605
DCN tasks at a glance
To configure DCN, perform the following tasks:
1.
2.
(Optional.) Configuring the NE ID and NE IP
3.
4.
(Optional.) Enabling the automatic report feature
5.
a.
(Optional.) Configuring the source MAC address of LLDP frames
b.
Advertising the LLDP management address
c.
Enabling the device to generate ARP entries for received management address LLDP TLVs
Enabling DCN
About this task
After DCN is enabled, the device assigns an NE IP to the loopback interface with the largest interface number and uses the interface for communication. The NE IP is specified as the management address and advertised in an LLDP frame. For more information about LLDP, see LLDP configuration in Layer 2—LAN Switching Configuration Guide .
Procedure
1. Enter system view. system-view
2. Enable DCN and enter DCN view. dcn
By default, DCN is disabled.
Configuring the NE ID and NE IP
About this task
Typically an NE automatically generates an NE IP according to its NE ID. The automatically generated NE IP changes when the NE ID changes. When you replan your network or an NE ID conflict occurs, you can manually configure the NE ID and NE IP. The manually configured NE IP does not change when the NE ID changes.
Procedure
1. Enter system view. system-view
2. Enter DCN view. dcn
3. Configure the NE ID.
ne-id id-number
By default, the NE ID is automatically generated by using the 24 low-order bits of the bridge
MAC address.
4. Configure the NE IP.
ne-ip ip-address { mask-length | mask }
606
By default, the NE IP is automatically generated by using 129 as the eight high-order bits and the NE ID as the rest 16 bits. The mask length is 32.
Configuring DCN VPN
About this task
Perform this task to ensure the independence of DCN services. For more information about VPN instances, see MPLS L3VPN configuration in MPLS Configuration Guide .
Procedure
1. Enter system view. system-view
2. Create a VPN instance and enter its view, or enter the view of an existing VPN instance.
ip vpn-instance vpn-instance-name
For more information about this command, see MPLS L3VPN commands in MPLS Command
Reference .
3. Quit VPN instance view. quit
4. Create a loopback interface and enter its view, or enter the view of an existing loopback interface. interface loopback interface-number
5. Associate the loopback interface with a VPN instance.
ip binding vpn-instance vpn-instance-name
By default, the loopback interface is not associated with a VPN instance.
For more information about this command, see MPLS L3VPN commands in MPLS Command
Reference .
Enabling the automatic report feature
Restrictions and guidelines
Perform this task only on GNE to enable it to automatically report online or offline events of NEs to the NMS.
Procedure
1. Enter system view. system-view
2. Enter DCN view. dcn
3. Enable the automatic report feature. auto-report
By default, the automatic report feature is disabled.
607
Configuring the LLDP features
Configuring the source MAC address of LLDP frames
About this task
Perform this task to configure the MAC address of the subinterface that runs Dot1q termination in the specified VLAN as the source MAC address of LLDP frames. For more information about Dot1q termination, see VLAN termination configuration in Layer 2—LAN Switching Configuration Guide .
For more information about LLDP, see LLDP configuration in Layer 2—LAN Switching Configuration
Guide .
Restrictions and guidelines
This feature is supported only on Layer 3 physical interfaces.
Procedure
1. Enter system view. system-view
2. Enter Layer 3 Ethernet interface view.
interface interface-type interface-number
3. Configure the MAC address of the Dot1q termination-enabled subinterface in the specified
VLAN as the source MAC address of LLDP frames. lldp source-mac vlan vlan-id
By default, the MAC address of the current Ethernet interface is specified as the source MAC address of LLDP frames.
For more information about this command, see LLDP commands in Layer 2—LAN Switching
Command Reference .
Advertising the LLDP management address
About this task
An NE on the DCN network learns the MAC address of its neighbor through LLDP. Perform this task to enable an NE to advertise the IP address of the specified loopback interface (management address) for ARP entry learning. For more information about LLDP, see LLDP configuration in Layer
2—LAN Switching Configuration Guide .
Restrictions and guidelines
This feature is supported only on Layer 3 physical interfaces.
Procedure
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Advertise the LLDP management address. lldp tlv-enable basic-tlv management-address-tlv [ ip-address | interface loopback interface-number ]
By default, the LLDP management address is not advertised.
For more information about this command, see LLDP commands in Layer 2—LAN Switching
Command Reference .
608
Enabling the device to generate ARP entries for received management address LLDP TLVs
About this task
This feature enables the device to generate an ARP entry for a received LLDP frame that meets the following requirements:
•
The LLDP frame carries a management address TLV.
•
The management address TLV contains an IPv4 address.
The generated ARP entry contains the management address and the source MAC address of the frame. For more information about LLDP, see LLDP configuration in Layer 2—LAN Switching
Configuration Guide .
Restrictions and guidelines
This feature is supported only on Layer 3 physical interfaces.
Procedure
1. Enter system view. system-view
2. Enter interface view.
interface interface-type interface-number
3. Enable the device to generate an ARP entry when receiving a management address LLDP
TLV. lldp management-address arp-learning vlan vlan-id
By default, the device does not generate an ARP entry when receiving a management address
LLDP TLV.
The vlan-id argument specifies the VLAN ID associated with a Layer 3 Ethernet subinterface in Dot1q termination.
For more information about this command, see LLDP commands in Layer 2—LAN Switching
Configuration Guide .
Verifying and maintaining DCN
Perform display tasks in any view.
•
Display the brief DCN information. display dcn
•
Display information about all online NEs on the DCN network. display dcn ne-info
DCN configuration examples
Example: Configuring DCN
Network configuration
As shown in Figure 130 , the GNE, Device A, and Device B run DCN in the same VPN instance. The
NMS uses SNMP to manage the GNE, and the GNE automatically sends notifications to the NMS to report online or offline events of NEs.
609
Figure 130 Network diagram
NMS
GNE
HGE
1/0
/1
HGE
1/0
/1
HGE
1/0
/2
HGE
1/0
/2
Device B
HGE1/0/2
HGE1/0/1
Device A
Procedure
1. Configure the GNE:
# Enable SNMP on the GNE. (Details not shown. For more information, see SNMP in Network
Management and Monitoring Configuration Guide .)
# Enable DCN, configure the NE ID as 100001 and NE IP as 11.1.1.1/32, and enable the automatic report feature.
<GNE> system-view
[GNE] dcn
[GNE-dcn] ne-id 100001
[GNE-dcn] ne-ip 11.1.1.1 32
[GNE-dcn] auto-report
[GNE-dcn] quit
# Create a VPN instance named dcn_vpn .
[GNE] ip vpn-instance dcn_vpn
[GNE-vpn-instance-dcn_vpn] quit
# Create interface Loopback 1023, and associate it with VPN instance dcn_vpn .
[GNE] interface loopback 1023
[GNE-LoopBack1023] ip binding vpn-instance dcn_vpn
[GNE-LoopBack1023] quit
# Enable LLDP globally.
[GNE] lldp global enable
# Enable the nearest bridge agents on HundredGigE 1/0/1 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
[GNE] interface hundredgige 1/0/1
[GNE-HundredGigE1/0/1] port link-mode route
[GNE-HundredGigE1/0/1] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/1 receives an LLDP frame.
[GNE-HundredGigE1/0/1] lldp management-address arp-learning vlan 4094
[GNE-HundredGigE1/0/1] quit
# Enable the nearest bridge agents on HundredGigE 1/0/2 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
610
[GNE] interface hundredgige 1/0/2
[GNE-HundredGigE1/0/2] port link-mode route
[GNE-HundredGigE1/0/2] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/2 receives an LLDP frame.
[GNE-HundredGigE1/0/2] lldp management-address arp-learning vlan 4094
[GNE-HundredGigE1/0/2] quit
# Create Ethernet subinterface HundredGigE 1/0/1.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
[GNE] interface hundredgige 1/0/1.4094
[GNE-HundredGigE1/0/1.4094] ip binding vpn-instance dcn_vpn
[GNE-HundredGigE1/0/1.4094] ip address unnumbered interface loopback 1023
[GNE-HundredGigE1/0/1.4094] vlan-type dot1q vid 4094
[GNE-HundredGigE1/0/1.4094] quit
# Create Ethernet subinterface HundredGigE 1/0/2.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
[GNE] interface hundredgige 1/0/2.4094
[GNE-HundredGigE1/0/2.4094] ip binding vpn-instance dcn_vpn
[GNE-HundredGigE1/0/2.4094] ip address unnumbered interface loopback 1023
[GNE-HundredGigE1/0/2.4094] vlan-type dot1q vid 4094
[GNE-HundredGigE1/0/2.4094] quit
# Enable OSPF process 65535 to run in VPN instance dcn_vpn , and create area 0.
[GNE] ospf 65535 vpn-instance dcn_vpn
[GNE-ospf-65535] area 0
[GNE-ospf-65535-area-0.0.0.0] network 0.0.0.0 255.255.255.255
[GNE-ospf-65535-area-0.0.0.0] quit
[GNE-ospf-65535] quit
# Set the OSPF network type for HundredGigE 1/0/1.4094 to P2P.
[GNE] interface hundredgige 1/0/1.4094
[GNE-HundredGigE1/0/1.4094] ospf network-type p2p
[GNE-HundredGigE1/0/1.4094] quit
# Set the OSPF network type for HundredGigE 1/0/2.4094 to P2P.
[GNE] interface hundredgige 1/0/2.4094
[GNE-HundredGigE1/0/2.4094] ospf network-type p2p
[GNE-HundredGigE1/0/2.4094] quit
2. Configure Device A:
# Enable DCN, configure the NE ID as 200002 and NE IP as 22.2.2.2/32.
<DeviceA> system-view
[DeviceA] dcn
[DeviceA-dcn] ne-id 200002
[DeviceA-dcn] ne-ip 22.2.2.2 32
[DeviceA-dcn] quit
# Create a VPN instance named dcn_vpn .
[DeviceA] ip vpn-instance dcn_vpn
[DeviceA-vpn-instance-dcn_vpn] quit
# Create interface Loopback 1023, and associate it with VPN instance dcn_vpn .
611
[DeviceA] interface loopback 1023
[DeviceA-LoopBack1023] ip binding vpn-instance dcn_vpn
[DeviceA-LoopBack1023] quit
# Enable LLDP globally.
[DeviceA] lldp global enable
# Enable the nearest bridge agents on HundredGigE 1/0/1 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] port link-mode route
[DeviceA-HundredGigE1/0/1] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/1 receives an LLDP frame.
[DeviceA-HundredGigE1/0/1] lldp management-address arp-learning vlan 4094
[DeviceA-HundredGigE1/0/1] quit
# Enable the nearest bridge agents on HundredGigE 1/0/2 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] port link-mode route
[DeviceA-HundredGigE1/0/2] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/2 receives an LLDP frame.
[DeviceA-HundredGigE1/0/2] lldp management-address arp-learning vlan 4094
[DeviceA-HundredGigE1/0/2] quit
# Create Ethernet subinterface HundredGigE 1/0/1.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
[DeviceA] interface hundredgige 1/0/1.4094
[DeviceA-HundredGigE1/0/1.4094] ip binding vpn-instance dcn_vpn
[DeviceA-HundredGigE1/0/1.4094] ip address unnumbered interface loopback 1023
[DeviceA-HundredGigE1/0/1.4094] vlan-type dot1q vid 4094
[DeviceA-HundredGigE1/0/1.4094] quit
# Create Ethernet subinterface HundredGigE 1/0/2.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
[DeviceA] interface hundredgige 1/0/2.4094
[DeviceA-HundredGigE1/0/2.4094] ip binding vpn-instance dcn_vpn
[DeviceA-HundredGigE1/0/2.4094] ip address unnumbered interface loopback 1023
[DeviceA-HundredGigE1/0/2.4094] vlan-type dot1q vid 4094
[DeviceA-HundredGigE1/0/2.4094] quit
# Enable OSPF process 65535 to run in VPN instance dcn_vpn , and create area 0.
[DeviceA] ospf 65535 vpn-instance dcn_vpn
[DeviceA-ospf-65535] area 0
[DeviceA-ospf-65535-area-0.0.0.0] network 0.0.0.0 255.255.255.255
[DeviceA-ospf-65535-area-0.0.0.0] quit
[DeviceA-ospf-65535] quit
# Set the OSPF network type for HundredGigE 1/0/1.4094 to P2P.
612
[DeviceA] interface hundredgige 1/0/1.4094
[DeviceA-HundredGigE1/0/1.4094] ospf network-type p2p
[DeviceA-HundredGigE1/0/1.4094] quit
# Set the OSPF network type for HundredGigE 1/0/2.4094 to P2P.
[DeviceA] interface hundredgige 1/0/2.4094
[DeviceA-HundredGigE1/0/2.4094] ospf network-type p2p
[DeviceA-HundredGigE1/0/2.4094] quit
3. Configure Device B:
# Enable DCN, configure the NE ID as 300003 and NE IP as 33.3.3.3/32.
<DeviceB> system-view
[DeviceB] dcn
[DeviceB-dcn] ne-id 300003
[DeviceB-dcn] ne-ip 33.3.3.3 32
[DeviceB-dcn] quit
# Create a VPN instance named dcn_vpn .
[DeviceB] ip vpn-instance dcn_vpn
[DeviceB-vpn-instance-dcn_vpn] quit
# Create interface Loopback 1023, and associate it with VPN instance dcn_vpn .
[DeviceB] interface loopback 1023
[DeviceB-LoopBack1023] ip binding vpn-instance dcn_vpn
[DeviceB-LoopBack1023] quit
# Enable LLDP globally.
[DeviceB] lldp global enable
# Enable the nearest bridge agents on HundredGigE 1/0/1 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] port link-mode route
[DeviceB-HundredGigE1/0/1] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/1 receives an LLDP frame.
[DeviceB-HundredGigE1/0/1] lldp management-address arp-learning vlan 4094
[DeviceB-HundredGigE1/0/1] quit
# Enable the nearest bridge agents on HundredGigE 1/0/2 to advertise basic LLDP TLVs and management address TLVs. The IP address of interface Loopback 1023 is specified as the management address.
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] port link-mode route
[DeviceB-HundredGigE1/0/2] lldp tlv-enable basic-tlv management-address-tlv interface loopback 1023
# Configure the system to issue the generated ARP entry to the Layer 3 Ethernet subinterface associated with VLAN 4094 in Dot1q termination after HundredGigE 1/0/2 receives an LLDP frame.
[DeviceB-HundredGigE1/0/2] lldp management-address arp-learning vlan 4094
[DeviceB-HundredGigE1/0/2] quit
# Create Ethernet subinterface HundredGigE 1/0/1.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
613
[DeviceB] interface hundredgige 1/1/1.4094
[DeviceB-HundredGigE1/0/1.4094] ip binding vpn-instance dcn_vpn
[DeviceB-HundredGigE1/0/1.4094] ip address unnumbered interface loopback 1023
[DeviceB-HundredGigE1/0/1.4094] vlan-type dot1q vid 4094
[DeviceB-HundredGigE1/0/1.4094] quit
# Create Ethernet subinterface HundredGigE 1/0/2.4094 that borrows the IP address of
Loopback 1023, and enable Dot1q termination on the interface.
[DeviceB] interface hundredgige 1/0/2.4094
[DeviceB-HundredGigE1/0/2.4094] ip binding vpn-instance dcn_vpn
[DeviceB-HundredGigE1/0/2.4094] ip address unnumbered interface loopback 1023
[DeviceB-HundredGigE1/0/2.4094] vlan-type dot1q vid 4094
[DeviceB-HundredGigE1/0/2.4094] quit
# Enable OSPF process 65535 to run in VPN instance dcn_vpn , and create area 0.
[DeviceB] ospf 65535 vpn-instance dcn_vpn
[DeviceB-ospf-65535] area 0
[DeviceB-ospf-65535-area-0.0.0.0] network 0.0.0.0 255.255.255.255
[DeviceB-ospf-65535-area-0.0.0.0] quit
[DeviceB-ospf-65535] quit
# Set the OSPF network type for HundredGigE 1/0/1.4094 to P2P.
[DeviceB] interface hundredgige 1/0/1.4094
[DeviceB-HundredGigE1/0/1.4094] ospf network-type p2p
[DeviceB-HundredGigE1/0/1.4094] quit
# Set the OSPF network type for HundredGigE 1/0/2.4094 to P2P.
[DeviceB] interface hundredgige 1/0/2.4094
[DeviceB-HundredGigE1/0/2.4094] ospf network-type p2p
[DeviceB-HundredGigE1/0/2.4094] quit
Verifying the configuration
# Display brief DCN information on the GNE.
[GNE] display dcn
DCN Brief Information
NE ID : 0x100001
NE IP : 11.1.1.1
Mask : 255.255.255.255
DCN interface: LoopBack1023
Auto report : Enabled
# Display all DCN NE information on the GNE.
[GNE] display dcn ne-info
DCN Network Elements Information
NE ID NE IP Metric Device Type
0x100001 11.1.1.1 0 HPE 12908E
0x200002 22.2.2.2 1 HPE 12908E
0x300003 33.3.3.3 1 HPE 12908E
614
Total number: 3
The output shows that GNE, Device A, and Device B are online. The GNE notifies the NMS of the online event. You can successfully ping the NE IP addresses of Device A and Device B from the
GNE.
# Remove Device B from the DCN network and display all DCN NE information for the GNE.
[GNE] display dcn ne-info
DCN Network Elements Information
NE ID NE IP Metric Device Type
0x100001 11.1.1.1 0 HPE 12908E
0x200002 22.2.2.2 1 HPE 12908E
Total number: 2
The output shows that GNE and Device A are online. The GNE notifies the NMS of the offline event of Device B. You can still successfully ping the NE IP address of Device A from the GNE.
615
Document conventions and icons
Conventions
This section describes the conventions used in the documentation.
Command conventions
Convention
Boldface
Italic
[ ]
{ x | y | ... }
[ x | y | ... ]
{ x | y | ... } *
[ x | y | ... ] *
Description
Bold text represents commands and keywords that you enter literally as shown.
Italic text represents arguments that you replace with actual values.
Square brackets enclose syntax choices (keywords or arguments) that are optional.
Braces enclose a set of required syntax choices separated by vertical bars, from which you select one.
Square brackets enclose a set of optional syntax choices separated by vertical bars, from which you select one or none.
Asterisk marked braces enclose a set of required syntax choices separated by vertical bars, from which you select at least one.
Asterisk marked square brackets enclose optional syntax choices separated by vertical bars, from which you select one choice, multiple choices, or none.
The argument or keyword and argument combination before the ampersand (&) sign can be entered 1 to n times.
A line that starts with a pound (#) sign is comments.
&<1-n>
#
GUI conventions
Convention
Boldface
Description
Window names, button names, field names, and menu items are in Boldface. For example, the New User window opens; click OK .
Multi-level menus are separated by angle brackets. For example, File > Create >
Folder .
Symbols
>
Convention
WARNING!
CAUTION:
IMPORTANT:
NOTE:
TIP:
Description
An alert that calls attention to important information that if not understood or followed can result in personal injury.
An alert that calls attention to important information that if not understood or followed can result in data loss, data corruption, or damage to hardware or software.
An alert that calls attention to essential information.
An alert that contains additional or supplementary information.
An alert that provides helpful information.
616
Network topology icons
Convention Description
Represents a generic network device, such as a router, switch, or firewall.
Represents a routing-capable device, such as a router or Layer 3 switch.
Represents a generic switch, such as a Layer 2 or Layer 3 switch, or a router that supports Layer 2 forwarding and other Layer 2 features.
Represents an access controller, a unified wired-WLAN module, or the access controller engine on a unified wired-WLAN switch.
Represents an access point.
Represents a wireless terminator unit.
Represents a wireless terminator.
Represents a mesh access point.
Represents omnidirectional signals.
Represents directional signals.
Represents a security product, such as a firewall, UTM, multiservice security gateway, or load balancing device.
Represents a security module, such as a firewall, load balancing, NetStream, SSL
VPN, IPS, or ACG module.
Examples provided in this document
Examples in this document might use devices that differ from your device in hardware model, configuration, or software version. It is normal that the port numbers, sample output, screenshots, and other information in the examples differ from what you have on your device.
617
Support and other resources
Accessing Hewlett Packard Enterprise Support
•
For live assistance, go to the Contact Hewlett Packard Enterprise Worldwide website: www.hpe.com/assistance
•
To access documentation and support services, go to the Hewlett Packard Enterprise Support
Center website: www.hpe.com/support/hpesc
Information to collect
•
Technical support registration number (if applicable)
•
Product name, model or version, and serial number
•
Operating system name and version
•
Firmware version
•
Error messages
•
Product-specific reports and logs
•
Add-on products or components
•
Third-party products or components
Accessing updates
•
Some software products provide a mechanism for accessing software updates through the product interface. Review your product documentation to identify the recommended software update method.
•
To download product updates, go to either of the following:
Hewlett Packard Enterprise Support Center Get connected with updates page: www.hpe.com/support/e-updates
Software Depot website: www.hpe.com/support/softwaredepot
•
To view and update your entitlements, and to link your contracts, Care Packs, and warranties with your profile, go to the Hewlett Packard Enterprise Support Center More Information on
Access to Support Materials page: www.hpe.com/support/AccessToSupportMaterials
IMPORTANT:
Access to some updates might require product entitlement when accessed through the Hewlett
Packard Enterprise Support Center. You must have an HP Passport set up with relevant entitlements.
618
Websites
Website
Networking websites
Hewlett Packard Enterprise Information Library for
Networking
Hewlett Packard Enterprise Networking website
Hewlett Packard Enterprise My Networking website
Hewlett Packard Enterprise My Networking Portal
Hewlett Packard Enterprise Networking Warranty
General websites
Hewlett Packard Enterprise Information Library
Hewlett Packard Enterprise Support Center
Hewlett Packard Enterprise Support Services Central
Contact Hewlett Packard Enterprise Worldwide
Subscription Service/Support Alerts
Software Depot
Customer Self Repair (not applicable to all devices)
Insight Remote Support (not applicable to all devices)
Link www.hpe.com/networking/resourcefinder www.hpe.com/info/networking www.hpe.com/networking/support www.hpe.com/networking/mynetworking www.hpe.com/networking/warranty www.hpe.com/info/enterprise/docs www.hpe.com/support/hpesc ssc.hpe.com/portal/site/ssc/ www.hpe.com/assistance www.hpe.com/support/e-updates www.hpe.com/support/softwaredepot www.hpe.com/support/selfrepair www.hpe.com/info/insightremotesupport/docs
Customer self repair
Hewlett Packard Enterprise customer self repair (CSR) programs allow you to repair your product. If a CSR part needs to be replaced, it will be shipped directly to you so that you can install it at your convenience. Some parts do not qualify for CSR. Your Hewlett Packard Enterprise authorized service provider will determine whether a repair can be accomplished by CSR.
For more information about CSR, contact your local service provider or go to the CSR website: www.hpe.com/support/selfrepair
Remote support
Remote support is available with supported devices as part of your warranty, Care Pack Service, or contractual support agreement. It provides intelligent event diagnosis, and automatic, secure submission of hardware event notifications to Hewlett Packard Enterprise, which will initiate a fast and accurate resolution based on your product’s service level. Hewlett Packard Enterprise strongly recommends that you register your device for remote support.
For more information and device support details, go to the following website: www.hpe.com/info/insightremotesupport/docs
Documentation feedback
Hewlett Packard Enterprise is committed to providing documentation that meets your needs. To help us improve the documentation, send any errors, suggestions, or comments to Documentation
Feedback ( [email protected]
). When submitting your feedback, include the document title,
619
part number, edition, and publication date located on the front cover of the document. For online help content, include the product name, product version, help edition, and publication date located on the legal notices page.
620
Index
Numerics
4-byte
6PE
BGP AS number suppression, 390
IPv6 BGP 6PE configuration, 466
A
ABR
OSPF summary network discard route, 98
ACL
action
adding
OSPF DD packet interface MTU, 105
address
DCN LLDP management address
IS-IS P2P interface hello packet source
MP-BGP supported address families, 270
adjacency
about OSPFv3, 517 comparison of OSPFv3 with OSPFv2, 517
OSPFv3 area configuration (NSSA), 551
OSPFv3 area configuration (stub), 546
OSPFv3 DR election configuration, 554
OSPFv3 IPsec profile configuration, 571
OSPFv3 route redistribution, 557
advanced OSPF features
1583 compatibility (OSPF), 110 dynamic host name mappings, 110
OSPF IPv4 unicast topology, 110 stub routers, 110
advertisement
advertising
BGP COMMUNITY configuration, 345
BGP COMMUNITY NO_ADVERTISE path
BGP default route (peer/peer group)(IPv4), 300
BGP default route (peer/peer group)(IPv6), 300
BGP fake AS number (IPv4), 371
BGP fake AS number (IPv6), 371
BGP optimal route (IPv4 unicast), 301
BGP optimal route (IPv6 unicast), 301
BGP route advertisement rules, 265
DCN LLDP management address, 608
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP GR configuration, 437
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
IS-IS link state info to BGP, 183
only the global unicast address in the NEXT_HOP
OSPF basics configuration, 130
OSPF link state information to BGP, 100
OSPF route summarization configuration, 134
RIP summary route advertisement configuration,
AIGP
applying
621
OSPFv3 IPsec profile for authenticating
RIPng IPsec profile (to a process), 504
RIPng IPsec profile (to an interface), 504
area
routing policy apply clause, 587
IS-IS authentication (area), 201
OSPF area configuration (NSSA), 91 ,
OSPF area configuration (stub), 91 ,
OSPF authentication (area), 123
OSPFv3 area configuration (NSSA), 521 ,
OSPFv3 area configuration (stub), 520 ,
ARP
DCN LLDP frame ARP entry enable, 609
AS
basic IPv4 BGP network configuration, 326
basic IPv6 BGP network configuration, 339
BGP 4-byte AS number suppression, 390
BGP AS number substitution, 371
BGP confederation compatibility, 350
BGP confederation settings, 349
BGP fake AS number advertisement, 371
BGP first AS number of EBGP route update
BGP link state (LS) AS number, 457
BGP local AS number appearance, 369
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
BGP path AS_PATH attribute, 261
BGP path AS_SEQUENCE attribute, 261
BGP path AS_SET attribute, 261
BGP private AS number removal, 373
enabling first-AS-number check for EBGP routes,
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP FRR configuration, 442
IPv4 BGP GR configuration, 437
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
IPv6 BGP FRR configuration, 450
IS-IS basic configuration, 170
IS-IS basics configuration, 216
IS-IS DIS election configuration, 221
routing policy AS_PATH list, 587 ,
AS_PATH
ASBR
OSPF redistributed route summarization, 95
OSPF summary network discard route, 98
ATT
OSPFv3 redistributed route summarization, 524
IS-IS ATT bit Level-1 LSP, 195 ,
attribute
IPv4 BGP COMMUNITY configuration, 352
MP-BGP MP_REACH_NLRI extended attribute,
622
MP-BGP MP_UNREACH_NLRI extended
authenticating
BGP peer keychain authentication, 417
BGP peer MD5 authentication, 415
IS-IS authentication (area), 201
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 202
RIPng IPsec profile application, 503
RIPv2 message authentication configuration,
auto
DCN automatic report enable, 607
automatic
RIPv2 automatic route summarization enable,
B backbone
backing up
bandwidth
IP routing IPv4 load sharing
basic BGP network configuration
BDR
BFD
about IPv6 static route BFD, 484
about RIP BFD configuration, 48
controlling adjacency establishment and maintenance based on BFD session state,
IPv4 BGP BFD configuration, 438
IPv6 BGP BFD configuration, 446
IPv6 IS-IS BFD configuration, 254
IPv6 static route BFD configuration, 484
IPv6 static route BFD control packet mode (direct
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IPv6 static route BFD echo packet mode, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop), 490
IS-IS FRR BFD enable (control packet mode),
IS-IS FRR BFD enable (echo packet mode), 207
OSPF detection configuration (bidirectional
OSPF detection configuration (single-hop echo),
OSPF FRR configuration, 122 , 122
OSPF PIC BFD control packet mode, 109
OSPF PIC BFD echo packet mode, 109
OSPFv3 BFD configuration, 536 ,
OSPFv3 FRR configuration, 539 , 539
OSPFv3 PIC BFD (control packet mode), 533
OSPFv3 PIC BFD (echo packet mode), 534
RIP BFD configuration (bidirectional control
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49 ,
RIP BFD single-hop echo detection, 67
RIP FRR BFD bidirectional control detection
RIP FRR BFD single-hop echo detection enable,
static routing BFD configuration, 19
static routing BFD control packet mode (direct
static routing BFD control packet mode (indirect
20 static routing BFD echo packet mode, 20
See also
4-byte AS number suppression, 390
4-byte AS number suppression restrictions, 391
623
Additional Paths feature configuration, 399
advertising only the global unicast address in
AIGP attribute configuration, 378
AS number quantity threshold setting, 375
AS_PATH attribute configuration, 369
basic BGP network building, 275
basic BGP network building (IPv4 multicast),
basic BGP network building (IPv4 unicast),
basic BGP network building (IPv6 multicast),
basic BGP network building (IPv6 unicast),
BFD configuration restrictions, 433
BGP Monitoring Protocol.
Use
BGP ORF capabilities negotiation, 389
confederation compatibility, 350
confederation settings configuration, 349
configuration restrictions, 275
configuring the next hop type selection rule for
default local preference configuration, 368
default route advertisement (peer/peer group),
delay time for responding to recursive next
dynamic peer configuration, 280
EBGP direct connections after link failure, 388
EBGP peer protection (low memory
EBGP session establishment (multiple hop),
EBGP session establishment restrictions
extended features configuration, 454 , 454
fake AS number advertisement, 371
first AS number of EBGP route update ignore,
GR configuration restrictions, 431
624
GTSM configuration restrictions, 416
IPv4 BGP Additional Paths feature configuration,
IPv4 BGP+IGP route redistribution, 331
IPv4 COMMUNITY configuration, 352
IPv4 confederation configuration, 357
IPv4 dynamic peer configuration, 333
IPv4 link state (LS) configuration, 463
IPv4 load balancing configuration, 408
IPv4 path selection configuration, 383
IPv4 route reflector configuration, 355
IS-IS link state info advertisement to BGP, 183
keepalive interval+hold time configuration, 318
large scale network management, 267
large-scale BGP network configuration, 344 , 344
link bandwidth attribute configuration, 317
link state (LS) AS number, 457
link state (LS) configuration, 456 link state (LS) route reflection, 456
link state (LS) router ID, 457
load balancing configuration, 397
local AS number appearance, 369
manual soft reset configuration, 396
MED attribute configuration, 375
MP-BGP extended attributes, 270
MP-BGP supported address families, 270
MPLS local label update delay, 320
NEXT_HOP attribute configuration restrictions,
nonstop routing (NSR) configuration, 432
optimal route advertisement, 301
optimal route selection delay configuration, 400
ORIGINATOR_ID attribute ignore, 348
OSPF BGP advertisement of link state
outgoing packet DSCP value, 405
peer flap dampening configuration, 403
peer keychain authentication, 417
permitting BGP routes with only tunnel next hops to participate in optimal route selection,
prioritized withdrawal of specific routes, 303
prioritized withdrawal of the default route, 302
private AS number removal, 373
received route preferred value, 367
resource public key infrastructure (RPKI)
route advertisement delay, 309
route advertisement rules, 265
route dampening configuration, 344
route preference configuration, 363
route reflection, 346 route reflector configuration, 346
route summarization, 299 route summarization restrictions, 299
routes received limit (peer/peer group), 312
routing policy AS_PATH list, 587 routing policy COMMUNITY list, 587
session establishment disable, 391
session state change logging, 320
SoO attribute configuration, 316
startup policy for BGP route updates, 309
suboptimal route flush to RIB, 406
TCP connection source address, 294
troubleshoot, 342 troubleshoot peer connection state, 342
bidirectional
IPv6 static route BFD control packet mode (direct
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
OSPF BFD detection configuration (bidirectional
RIP BFD configuration (bidirectional control
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
static routing BFD control packet mode (direct
static routing BFD control packet mode (indirect
BMP
BGP Monitoring Protocol configuration, 454
Border Gateway Protocol.
Use
broadcast
OSPF interface network type, 93
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
C calculating
IS-IS SPF calculation interval, 186
OSPF SPF calculation interval, 102
OSPFv3 FRR backup next hop calculation (LFA
OSPFv3 SPF calculation interval, 529
checking
OSPFv3 DD packet ignore MTU check, 531
circuit
classless inter-domain routing.
Use CIDR clearing
routing table statistics (IPv4), 13
routing table statistics (IPv6), 15
CLNP
625
COMMUNITY
BGP COMMUNITY configuration, 345
BGP COMMUNITY path attribute, 261
IPv4 BGP COMMUNITY configuration, 352
routing policy COMMUNITY list, 592
community
comparing
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
confederating
BGP confederation compatibility, 350
BGP confederation settings, 349
BGP MED route comparison (confederation
configuring
bandwidth reference value, 526
BGP Additional Paths feature, 399
BGP AS number substitution (IPv4), 371
BGP AS number substitution (IPv6), 371
BGP confederation compatibility, 350
BGP confederation settings, 349
BGP default local preference (IPv4), 368
BGP default local preference (IPv6), 368
BGP FRR (IPv4 unicast address), 433
BGP FRR (IPv6 unicast address), 433
BGP keepalive interval+hold time, 318
BGP link bandwidth attribute (IPv4), 317
BGP link bandwidth attribute (IPv6), 317
BGP link state (LS) route reflection, 456
BGP load balancing (IPv4), 397
626
BGP load balancing (IPv6), 397
BGP manual soft reset (IPv4), 396
BGP manual soft reset (IPv6), 396
BGP MED default value (IPv4), 375
BGP MED default value (IPv6), 375
BGP Monitoring Protocol (BMP), 454
BGP MPLS local label update delay, 320
BGP NEXT_HOP attribute (IPv4), 365
BGP NEXT_HOP attribute (IPv6), 365
BGP optimal route selection delay, 400
BGP route advertisement delay, 309
BGP route dampening (IPv4), 344
BGP route dampening (IPv6), 344
BGP route distribution filtering policy (IPv4), 303
BGP route distribution filtering policy (IPv6), 303
BGP route preference (IPv4), 363
BGP route preference (IPv6), 363
BGP route reception filtering policy (IPv4), 314
BGP route reception filtering policy (IPv6), 314
BGP route reflector (IPv4), 346
BGP route reflector (IPv6), 346
BGP route sending rate configuration, 307
BGP route summarization (manual)(IPv4), 299
BGP route summarization (manual)(IPv6), 300
BGP route update interval (IPv4), 308
BGP route update interval (IPv6), 308
BGP RPKI connection parameters, 418
DCN LLDP frame source MAC address, 608
dynamic host name mapping, 111 , 111
EBGP peer group (IPv4 multicast address), 285
EBGP peer group (IPv4 unicast address), 285
EBGP peer group (IPv6 multicast address), 285
EBGP peer group (IPv6 unicast address), 285
extended BGP features, 454 , 454
IBGP peer group (IPv4 multicast address), 283
IBGP peer group (IPv4 unicast address), 283
IBGP peer group (IPv6 multicast address), 283
IBGP peer group (IPv6 unicast address), 283
interface PBR (packet source-IP-based), 480
interface PBR (packet type-based), 479
IP routing inter-protocol FRR, 8
IP routing load sharing (source+destination
IP routing load sharing mode, 3
IP routing policy-based recursive lookup, 9
IPv4 BGP Additional Paths feature, 411
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 PBR interface (packet type-based), 584
IPv6 PBR local (packet type-based), 583
627
IPv6 static route BFD control packet mode (direct
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IPv6 static route BFD echo packet mode, 485
IPv6 static routing basics, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop), 490
IS-IS authentication (area), 201
IS-IS authentication (neighbor relationship), 200
IS-IS authentication (routing domain), 202
IS-IS FRR (routing policy), 206
IS-IS FRR backup next hop (LFA calculation), 206
IS-IS interface DIS priority, 187
IS-IS interface P2P network type, 172
IS-IS interface tag value, 188
IS-IS LSP-calculated route filtering, 181
IS-IS multi-instance processes, 172 ,
IS-IS redistributed route filtering, 182
IS-IS route convergence priority, 193
IS-IS route redistribution, 180 ,
IS-IS route summarization, 179
IS-IS route update suppression, 192
IS-IS system ID > host name mapping, 196
IS-IS system ID > host name mapping (dynamic),
local PBR (packet type-based), 477
next hop recursion loop suppression, 10
next hop type selection rule for optimal route
OSPF authentication (area), 123
OSPF authentication (interface), 123
OSPF bandwidth reference value, 97
OSPF BFD detection (bidirectional control),
OSPF BFD detection (single-hop echo), 115
OSPF FRR backup next hop (routing policy),
OSPF FRR backup next hop calculation (LFA
OSPF FRR BFD control packet mode, 122
OSPF FRR BFD echo packet mode, 122
OSPF GR helper (non-IETF), 113
OSPF GR restarter (non-IETF), 112
OSPF GTSM (interface view), 124
OSPF interface network type (broadcast), 93
OSPF interface network type (NBMA), 93
OSPF interface network type (P2MP), 94
OSPF interface network type (P2P), 94
OSPF PIC BFD control packet mode, 109
OSPF PIC BFD echo packet mode, 109
OSPF prefix suppression (interface), 108
OSPF prefix suppression (OSPF process),
OSPF received route filtering, 96 , 96
OSPF redistributed route summarization, 95
OSPF route redistribution, 133
628
OSPF summary network discard route, 98
OSPFv3 authentication (area), 540
OSPFv3 authentication (interface), 540
OSPFv3 FRR backup next hop (routing policy),
OSPFv3 FRR backup next hop calculation (LFA
OSPFv3 FRR BFD control packet mode, 539
OSPFv3 FRR BFD echo packet mode, 539
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 interface DR priority, 530
OSPFv3 network management, 543
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
OSPFv3 PIC BFD (control packet mode), 533
OSPFv3 PIC BFD (echo packet mode), 534
OSPFv3 prefix suppression (interface), 533
OSPFv3 prefix suppression (OSPFv3 process),
OSPFv3 received route filtering, 525
OSPFv3 route redistribution, 557
OSPFv3 route redistribution (default route), 527
OSPFv3 route summarization, 560
OSPFv3 route summarization (on ASBR), 524
RIP additional routing metric, 39
RIP BFD (bidirectional control detection), 72
RIP BFD (bidirectional control detection/direct
RIP BFD (bidirectional control
detection/indirect neighbor), 50
RIP BFD (single-hop echo detection/neighbor),
RIP BFD (single-hop echo detection/specific
RIP BFD single-hop echo detection, 67
RIP interface additional metric, 59
RIP received/redistributed route filtering, 42
RIP route redistribution, 43 ,
RIP summary route advertisement, 61
RIPng packet zero field check, 503
RIPng received/redistributed route filtering,
RIPng route redistribution, 498 ,
RIPng route summarization, 496
RIPv2 message authentication, 53
599 routing policy (IPv4 route redistribution), 599
routing policy (IPv6 route redistribution), 602
routing policy apply clause, 596
routing policy AS_PATH list, 589
routing policy COMMUNITY list, 592
routing policy continue clause, 598
routing policy if-match clause, 594
routing policy RD list, 593 routing policy tag list, 593
startup policy for BGP route updates, 309
static routing BFD (direct next hop), 25
static routing BFD (indirect next hop), 27
static routing BFD control packet mode (direct
static routing BFD control packet mode (indirect
20 static routing BFD echo packet mode, 20
static routing default route, 33
static routing FRR (auto select backup next hop),
static routing FRR (backup next hop), 21
static routing FRR BFD echo packet mode, 22
update suppression during route flaps, 107
connecting
BGP TCP connection source address, 294
EBGP direct connections after link failure, 388
continue clause (routing policy), 587 ,
controlling adjacency establishment and maintenance based
IPv6 static route BFD control packet mode (direct
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IS-IS SPF calculation interval, 186
RIP additional routing metric configuration, 39
RIP interface advertisement, 37 ,
RIP interface reception, 37 , 37 ,
RIP interface suppression, 37 , 37
RIP route control configuration, 39
629
convergence priority (IS-IS), 193
cost
creating
CSNP
IS-IS CSNP packet send interval, 184
D dampening
data communication network.
See
database
DCN
basic concepts, 605 configuration, 605 ,
LLDP frame ARP entry enable, 609
LLDP frame source MAC address, 608
LLDP management address advertisement,
NE ID+NE IP configuration, 606
DD
OSPFv3 DD packet ignore MTU check, 531
default
BGP default local preference, 368
BGP default route advertisement (peer/peer
IPv6 default route configuration, 493
IS-IS default route advertisement, 179
OSPFv3 route redistribution (default route),
RIP default route advertisement, 41
RIPng default route advertisement, 497
static routing configuration.
See under static routing delaying
BGP MPLS local label update delay, 320
OSPFv3 LSA transmission delay, 529
destination
IP routing load sharing configuration
(source+destination address based), 15
detecting
OSPF BFD detection configuration (bidirectional
OSPF BFD detection configuration (single-hop
OSPF FRR BFD control packet mode, 122
OSPF FRR BFD echo packet mode, 122
OSPFv3 FRR BFD control packet mode, 539
OSPFv3 FRR BFD echo packet mode, 539
RIP BFD configuration (bidirectional control
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49 ,
RIP BFD single-hop echo detection, 48 ,
device
basic IPv4 BGP network configuration, 326
basic IPv6 BGP network configuration, 339
interface PBR configuration (packet
interface PBR configuration (packet type-based),
IP routing load sharing mode, 3
IPv4 BGP Additional Paths feature configuration,
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP dynamic peer configuration, 333
IPv4 BGP GR configuration, 437
IPv4 BGP link state (LS) configuration, 463
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP RPKI configuration, 423
630
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP 6PE configuration, 466
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
IPv6 BGP RPKI configuration, 426
IPv6 IS-IS basic configuration, 249
IPv6 IS-IS BFD configuration, 254
IPv6 IS-IS FRR configuration, 256
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration (packet
IPv6 static routing basics, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop),
IS-IS basics configuration, 216
IS-IS DIS election configuration, 221
IS-IS multi-instance processes configuration,
IS-IS remote LFA FRR configuration, 241
IS-IS route redistribution, 225
local PBR configuration (packet type-based),
OSPF area configuration (NSSA), 140
OSPF area configuration (stub), 137
OSPF backbone router type, 82 ,
OSPF basics configuration, 130
OSPF DR election configuration, 142
OSPF internal router type, 82 ,
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF virtual link configuration, 146
OSPFv3 area configuration (NSSA), 551
OSPFv3 area configuration (stub), 546
OSPFv3 DR election configuration, 554
OSPFv3 IPsec profile configuration, 571
OSPFv3 route redistribution, 557
OSPFv3 route summarization, 560
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
detection/specific destination), 69
RIP BFD single-hop echo detection, 67
RIP interface additional metric configuration, 59
RIP route redistribution configuration, 57
RIP summary route advertisement configuration,
RIPng basic configuration, 505
RIPng route redistribution configuration, 508
routing policy configuration, 599
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
static routing basic configuration, 23
static routing BFD configuration (direct next hop),
static routing BFD configuration (indirect next
static routing configuration, 23
DIS
static routing FRR configuration, 30
IS-IS DIS election configuration, 221
IS-IS interface DIS priority, 187
disabling
BGP session establishment (IPv4), 391
BGP session establishment (IPv6), 391
IPv4 next hop recursion loop suppression, 10
IPv6 next hop recursion loop suppression, 11
IS-IS interface packet send/receive, 189
MPLS local IFNET tunnel establishment, 407
OSPF interface packet send/receive disable, 104
631
OSPFv3 interface packet send/receive, 531
recursion policy for routes received from a
displaying
routing table statistics (IPv4), 13
routing table statistics (IPv6), 15
distributing
BGP IGP route redistribution, 297
IP routing extension attribute redistribution, 3
IP routing route redistribution, 3
IPv4 BGP+IGP route redistribution, 331
IS-IS route redistribution, 180 ,
OSPF route redistribution configuration, 133
OSPFv3 route redistribution, 527 ,
RIPng received/redistributed route filtering,
RIPng route redistribution, 498
RIPng route redistribution configuration, 508
domain
IS-IS authentication (routing domain), 202
DR
OSPF DR election configuration, 142
OSPFv3 DR election configuration, 554
OSPFv3 interface DR priority, 530
DSCP
BGP outgoing packet DSCP value, 405
OSPF outgoing packet DSCP value, 105
OSPFv3 outgoing packet DSCP value, 531
dynamic
IP routing dynamic routing protocols, 1
IS-IS system ID > host name mapping, 197
E
EBGP
BGP confederation settings, 349
BGP first AS number of route update ignore,
BGP private AS number removal from
direct connections after link failure, 388
enabling first-AS-number check for EBGP routes,
peer group configuration (IPv4 multicast address),
peer group configuration (IPv4 unicast address),
peer group configuration (IPv6 multicast address),
peer group configuration (IPv6 unicast address),
session establishment (multiple hop), 387
echo
IPv6 static route BFD echo packet mode, 485
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
detection/specific destination), 69
RIP BFD single-hop echo detection, 48 ,
static routing BFD echo packet mode, 20
ECMP
IP routing ECMP enhanced mode, 7
electing
OSPF DR election configuration, 142
OSPFv3 DR election configuration, 554
enabling
BGP peer keychain authentication (IPv4), 417
BGP peer keychain authentication (IPv6), 417
BGP prioritized withdrawal of specific routes, 303
BGP route flapping logging (IPv4), 321
BGP route flapping logging (IPv6), 321
BGP session state change logging (IPv4), 320
BGP session state change logging (IPv6), 320
enabling IS-IS to advertise the maximum link cost
first-AS-number check for EBGP routes, 306
IS-IS FRR BFD (control packet mode), 207
632
IS-IS FRR BFD (echo packet mode), 207
IS-IS LSP fragment extension, 190
IS-IS neighbor state change logging, 197
IS-IS P2P interface hello packet source
IS-IS PIC BFD control packet mode, 200
OSPF RFC 1583 compatibility, 110
OSPFv3 neighbor state change logging, 542
prioritized withdrawal of the default route, 302
RIP FRR BFD single-hop echo detection, 52
Enabling
IP routing IPv4 load sharing
enabling
BGP 4-byte AS number suppression (IPv4),
BGP 4-byte AS number suppression (IPv6),
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
BGP ORF capabilities negotiation, 389
BGP peer MD5 authentication (IPv4), 415
BGP peer MD5 authentication (IPv6), 415
EBGP direct connections after link failure, 388
EBGP session establishment (multiple
EBGP session establishment (multiple hop)(IPv6),
IP routing ECMP enhanced mode, 7
IS-IS interface hello packet send, 189
IS-IS PIC BFD echo packet mode, 200
RIP FRR BFD bidirectional control detection, 51
RIP update source IP address check, 53
RIPv1 incoming message zero field check, 52
RIPv2 automatic route summarization, 40
enhancing
establishing
BGP session establishment disable, 391
EBGP session establishment (multiple hop), 387
exit overflow interval (OSPF), 103
extending
IS-IS LSP fragment extension, 190
MP-BGP MP_REACH_NLRI extended attribute,
MP-BGP MP_UNREACH_NLRI extended
Exterior Gateway Protocol.
Use EGP external
OSPF LSDB external LSAs max, 106
external BGP.
Use EGP
F
FIB
IP routing load sharing mode, 3
filtering
BGP route distribution filtering policy, 303
BGP route reception filtering policy, 314
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP FRR configuration, 442
IPv4 BGP GR configuration, 437
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
633
IPv6 BGP FRR configuration, 450
IS-IS LSP-calculated routes, 181
IS-IS redistributed routes, 182
OSPF outbound LSA (on interface), 106
OSPF outbound LSAs (specified neighbor),
OSPF received route filtering, 96
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 received route filtering, 525
RIP received/redistributed route filtering, 42
RIPng received/redistributed route filtering,
routing policy apply clause, 596
routing policy AS_PATH list, 587 ,
routing policy COMMUNITY list, 587 ,
routing policy configuration, 587 ,
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 598
routing policy if-match clause, 594
routing policy prefix list, 587
routing policy RD list, 593 routing policy tag list, 593
flapping
BGP route flapping logging, 321
flooding
flushing
BGP suboptimal route to RIB, 406
forwarding
dynamic host name mapping configuration,
interface PBR configuration (packet
interface PBR configuration (packet
IP routing inter-protocol FRR, 8
IPv6 IS-IS BFD configuration, 254
IPv6 PBR interface configuration, 581
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 581
IPv6 PBR local configuration (packet type-based),
IPv6 PBR policy configuration, 578
local PBR configuration (packet type-based), 477
PBR policy specification (interface PBR), 476
PBR policy specification (local PBR), 476
update suppression during route flaps
fragment
IS-IS LSP fragment extension, 190
frame
DCN LLDP frame ARP entry enable, 609
FRR
BFD bidirectional control detection enable, 51
BFD single-hop echo detection enable, 52
IP routing inter-protocol FRR, 8
IPv4 BGP FRR configuration, 442
IPv6 BGP FRR configuration, 450
IPv6 IS-IS FRR configuration, 256
IS-IS backup path selection policy priority, 211
IS-IS FRR backup next hop configuration (LFA
IS-IS FRR BFD enable (control packet mode),
IS-IS FRR BFD enable (echo packet mode), 207
IS-IS FRR configuration (routing policy), 206
IS-IS remote LFA FRR configuration, 241
OSPF backup next hop (routing policy), 119
OSPF backup path selection policy priority, 119
OSPF FRR BFD control packet mode, 122
OSPF FRR BFD echo packet mode, 122
634
OSPFv3 backup next hop (routing policy), 538
OSPFv3 backup next hop calculation (LFA
OSPFv3 FRR BFD control packet mode, 539
OSPFv3 FRR BFD echo packet mode, 539
OSPFv3 FRR configuration, 537 ,
static routing FRR configuration, 21 ,
G
garbage-collect timer (RIP), 43
gateway network element (GNE)
DCN automatic report enable, 607
Generalized TTL Security Mechanism.
Use
generating
OSPFv3 LSA generation interval, 529
Graceful Restart (GR)
IPv4 BGP GR configuration, 437
OSPF GR helper configuration, 113
OSPF GR restarter configuration, 112
OSPFv3 GR configuration, 535 ,
OSPFv3 GR helper configuration, 535
OSPFv3 GR restarter configuration, 535
RIP GR helper configuration, 47
RIP GR restarter configuration, 47
GTSM
OSPF configuration (area view), 124
OSPF configuration (interface view), 124
H hello
IS-IS hello packet send interval, 184
IS-IS interface hello packet send, 189
IS-IS P2P interface hello packet source address
hop
EBGP session establishment (multiple hop), 387 ,
OSPF BFD detection configuration (single-hop
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49
host
IS-IS system ID > host name mapping, 196
OSPF host route advertisement, 100
RIP host route reception disable, 41
I
IBGP
BGP confederation settings, 349
peer group configuration (IPv4 multicast address),
peer group configuration (IPv4 unicast address),
peer group configuration (IPv6 multicast address),
peer group configuration (IPv6 unicast address),
ICMP
OSPF area configuration (NSSA), 140
OSPF area configuration (stub), 137
OSPF basics configuration, 130
OSPF DR election configuration, 142
635
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF virtual link configuration, 146
OSPFv3 route summarization, 560
ID
BGP link state (LS) router ID, 457
DCN NE ID+NE IP configuration, 606
IETF
ignoring
BGP first AS number of EBGP route updates,
BGP IGP metrics during optimal route
BGP ORIGINATOR_ID attribute (IPv4), 348
BGP ORIGINATOR_ID attribute (IPv6), 348
BGP router IDs during optimal route selection,
OSPFv3 DD packet MTU check, 531
IGP
BGP IGP route redistribution, 297
BGP ORIGIN path attribute, 261
IPv4 BGP+IGP route redistribution, 331
IS-IS basic configuration, 170
IS-IS basics configuration, 216
IS-IS DIS election configuration, 221
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49
RIP neighbor specification, 39
INCOMPLETE
BGP ORIGIN path attribute, 261
injecting
instance
inter-area
interface interface PBR configuration (packet
interface PBR configuration (packet type-based),
IPv6 PBR interface configuration, 581
IPv6 PBR interface configuration (packet
Intermediate System-to-Intermediate System.
Use
internal
BGP.
Use
INTERNET
BGP COMMUNITY path attribute, 261
interval
BGP route update interval, 308
IS-IS CSNP packet send interval, 184
IS-IS hello packet send interval, 184
IS-IS LSP generation interval, 185
IS-IS LSP receiving interval, 186
IS-IS LSP refresh interval, 185
IS-IS LSP sending interval, 186
IS-IS SPF calculation interval, 186
OSPF exit overflow interval, 103
OSPF LSA arrival interval, 102
OSPF LSA generation interval, 103
OSPF SPF calculation interval, 102
OSPFv3 LSA generation interval, 529
OSPFv3 SPF calculation interval, 529
RIP triggered update interval, 45
RIPng triggered update send interval, 500
intra-area
IP preferring BGP routes of specific next hop type
during optimal route selection, 382
IP addressing
DCN NE ID+NE IP configuration, 606
636
RIP update source IP address check, 53
IP routing
about OSPF authentication, 122
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed,
active route max number configuration, 12
advertising only the global unicast address in
applying BGP RPKI validation state to optimal
basic BGP network building, 275
basic BGP network building (IPv4 multicast),
basic BGP network building (IPv4 unicast),
basic BGP network building (IPv6 multicast),
basic BGP network building (IPv6 unicast),
basic BGP network configuration maintain,
323 basic BGP network configuration verify, 323
BGP 4-byte AS number suppression
BGP AS number quantity threshold setting,
BGP BFD configuration restrictions, 433
BGP COMMUNITY configuration, 345
BGP confederation settings, 349
BGP configuration restrictions, 275
BGP default local preference, 368
BGP default route advertisement (peer/peer
BGP EBGP session establishment restrictions
BGP first AS number of EBGP route update
637
BGP GR configuration restrictions, 431
BGP GTSM configuration restrictions, 416
BGP large scale network management, 267
BGP link bandwidth attribute, 317
BGP MPLS local label update delay, 320
BGP NEXT_HOP attribute configuration
BGP optimal route advertisement, 301
BGP peer keychain authentication, 417
BGP peer MD5 authentication, 415
BGP protocols and standards, 273
BGP received route preferred value, 367
BGP route advertisement delay, 309
BGP route dampening configuration, 344
BGP route flapping logging, 321
BGP route summarization restrictions, 299
BGP route update interval, 308
BGP RPKI connection parameters, 418
BGP RPKI validation state advertisement, 421
BGP session establishment disable, 391
BGP session state change logging, 320
BGP SNMP notification enable, 322
BGP suboptimal route flush to RIB, 406
BGP TCP connection source address, 294
comparison of OSPFv3 with OSPFv2, 517
DCN NE ID+NE IP configuration, 606
dynamic host name mapping configuration,
EBGP peer protection (low memory
ECMP enhanced mode enable, 7 , 7
enabling IS-IS to advertise the maximum link
extended BGP features accounting, 454 , 454
extension attribute redistribution, 3
flushing route attribute information from RIB to
inter-protocol FRR configuration, 8
IPv4 ECMP enhanced mode enable, 7
IPv4 load sharing (bandwidth-based), 4
IPv4 prefix list configuration, 589
IPv6 default route.
See under IPv6 static routing
IPv6 IS-IS FRR configuration, 256
IPv6 PBR logging feature enable, 582
IPv6 policy-based routing.
See
IPv6 prefix list configuration, 589
IPv6 route fast switchover enable, 9
IPv6 static routing.
See
IPv6 static routing verify, 485
IS-IS authentication (area), 201
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 202
IS-IS basic configuration, 170
IS-IS basics configuration, 216
IS-IS CSNP packet send interval, 184
IS-IS default route advertisement, 179
IS-IS DIS election configuration, 221
IS-IS FRR backup path selection policy priority,
638
IS-IS hello packet send interval, 184
IS-IS interface DIS priority, 187
IS-IS interface hello packet send, 189
IS-IS interface packet send/receive, 189
IS-IS interface tag value, 188
IS-IS link state info advertisement to BGP, 183
IS-IS LSP fragment extension, 190
IS-IS LSP-calculated route filtering, 181
IS-IS multi-instance processes configuration, 245
IS-IS network optimization, 184
IS-IS PIC BFD control packet mode, 200
IS-IS PIC BFD echo packet mode, 200
IS-IS PIC configuration restrictions, 199
IS-IS protocols and standards, 166
IS-IS redistributed route filtering, 182
IS-IS remote LFA FRR configuration, 241
IS-IS route convergence priority, 193
IS-IS route redistribution, 180 ,
IS-IS route summarization, 179
IS-IS route update suppression, 192
IS-IS SPF calculation interval, 186
IS-IS system ID > host name mapping, 196
large-scale BGP network configuration, 344 ,
large-scale BGP network configuration
large-scale BGP network configuration verify,
load sharing configuration
(source+destination address based), 15
MP-BGP protocols and standards, 273
next hop recursion loop suppression
OSPF area configuration (NSSA), 91 ,
OSPF area configuration (stub), 91 ,
OSPF basics configuration, 130
OSPF BFD detection configuration
OSPF BFD detection configuration
OSPF BGP advertisement of link state
OSPF DD packet interface MTU, 105
OSPF DR election configuration, 142
OSPF exit overflow interval, 103
OSPF FRR backup path selection policy
OSPF FRR BFD control packet mode, 122
OSPF FRR BFD echo packet mode, 122
OSPF GTSM configuration (area view), 124
639
OSPF GTSM configuration (interface view), 124
OSPF host route advertisement, 100
OSPF inter-area route summarization, 95
OSPF interface max packet length, 105
OSPF interface network type (broadcast), 93
OSPF interface network type (NBMA), 93
OSPF interface network type (P2MP), 94
OSPF interface network type (P2P), 94
OSPF interface packet send/receive disable, 104
OSPF logging and SNMP notifications, 125
OSPF LSA arrival interval, 102
OSPF LSA generation interval, 103
OSPF LSA generation/advertisement/reception
OSPF LSA transmission delay, 101
OSPF LSDB external LSAs max, 106
OSPF neighbor state change, 125
OSPF outbound LSA filtering (on interface), 106
OSPF outbound LSA filtering (specified neighbor),
OSPF outgoing packet DSCP value, 105
OSPF protocols and standards, 86
OSPF received route filtering, 96
OSPF RFC 1583 compatibility, 110
OSPF route redistribution (another routing
OSPF route redistribution (default route), 99
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF SPF calculation interval, 102
OSPF summary network discard route, 98
OSPF virtual link configuration, 146
OSPFv3 area configuration (NSSA), 521 ,
OSPFv3 area configuration (stub), 520 ,
OSPFv3 DD packet ignore MTU check, 531
OSPFv3 DR election configuration, 554
OSPFv3 FRR BFD control packet mode, 539
OSPFv3 FRR BFD echo packet mode, 539
OSPFv3 inter-area route summarization, 524
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 interface DR priority, 530
OSPFv3 interface packet send/receive
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
OSPFv3 log max number setting, 542
OSPFv3 logging and SNMP notifications, 542
OSPFv3 LSA generation interval, 529
OSPFv3 LSA transmission delay, 529
OSPFv3 neighbor state change logging, 542
OSPFv3 network management traps, 543
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
OSPFv3 outgoing packet DSCP value, 531
640
OSPFv3 prefix suppression, 532
OSPFv3 protocols and standards, 518
OSPFv3 received route filtering, 525
OSPFv3 route redistribution, 527 ,
OSPFv3 route summarization, 560
OSPFv3 SPF calculation interval, 529
PBR logging feature enable, 477
policy configuration (IPv4 route redistribution),
policy configuration (IPv6 route redistribution),
policy filtering, 587 policy filters, 587
policy-based routing.
Use
prioritized withdrawal of specific routes, 303
prioritized withdrawal of the default route, 302
RIB nonstop routing (NSR) configuration, 7
RIP additional routing metric configuration, 39
RIP BFD configuration (bidirectional control
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49 ,
RIP BFD single-hop echo detection, 67
RIP default route advertisement, 41
RIP FRR configuration restrictions, 51
RIP host route reception disable, 41
RIP interface additional metric configuration,
RIP interface advertisement control, 37 ,
RIP interface reception control, 37 ,
RIP neighbor specification, 39
RIP network management configuration, 47
RIP outgoing packet DSCP value, 46
RIP packet send rate configuration, 45
RIP poison reverse configuration, 44
RIP preference configuration, 42
RIP received/redistributed route filtering, 42
RIP route control configuration, 39
RIP route redistribution configuration, 43 ,
RIP routing loop prevention, 34
RIP security configuration, 52
RIP split horizon configuration, 44
RIP summary route advertisement
RIP triggered update interval configuration, 45
RIP update source IP address check, 53
641
RIPng basic configuration, 495 ,
RIPng default route advertisement, 497
RIPng FRR configuration, 502 ,
RIPng IPsec profile application, 503
RIPng network optimization, 498
RIPng packet and advertisement, 494
RIPng packet zero field check configuration, 503
RIPng poison reverse configuration, 499
RIPng protocols and standards, 494
RIPng received/redistributed route filtering, 497
RIPng route redistribution, 498
RIPng route redistribution configuration, 508
RIPng route summarization, 496
RIPng routing metric configuration, 496
RIPng split horizon configuration, 499
RIPng timer configuration, 498
RIPng triggered update send interval, 500
RIPv1 message zero field check, 52
RIPv2 message authentication configuration, 53
RIPv2 route summarization configuration, 40
route recursion, 3 route redistribution, 3
routing policy-based recursive lookup, 9
routing policy-based recursive lookup
routing table maintain (IPv4), 12
routing table maintain (IPv6), 14
routing table verify (IPv4), 12
routing table verify (IPv6), 14
setting interface cost upon LSDB overload, 194
setting OSPFv3 packet timers, 528
split horizon and poison reverse configuration,
static route deletion, 18 static route group configuration, 18
static routing basic configuration, 23
static routing BFD, 19 static routing BFD configuration, 19
static routing BFD configuration (direct next
static routing BFD configuration (indirect next
static routing BFD control packet mode (direct
static routing BFD control packet mode
20 static routing BFD echo packet mode, 20
static routing configuration, 17 , 17 ,
static routing default route configuration, 33
static routing FRR, 21 static routing FRR configuration, 21 ,
troubleshooting BGP peer connection state,
troubleshooting OSPF configuration, 158
troubleshooting OSPF incorrect routing
troubleshooting OSPF no neighbor
update suppression during route flaps
IPsec
IPv4
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
RIPng IPsec profile application, 503
BGP link bandwidth attribute, 317
EBGP peer group configuration (IPv4
EBGP peer group configuration (IPv4 unicast
EBGP peer protection (low memory
EBGP session establishment (multiple hop),
IBGP peer group configuration (IPv4 multicast
IBGP peer group configuration (IPv4 unicast
IP routing FIB route max lifetime, 6
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
IPv6 BGP 6PE configuration, 466
IS-IS basic configuration, 170
IS-IS basics configuration, 216
IS-IS DIS election configuration, 221
OSPF area configuration (NSSA), 140
OSPF area configuration (stub), 137
OSPF basics configuration, 130
OSPF DR election configuration, 142
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF virtual link configuration, 146
prefix list configuration, 589
routing policy ACLs, 587 routing policy configuration, 587 ,
routing policy configuration (IPv4 route
routing policy prefix list, 587
routing table display, 12 routing table maintain, 12
routing table statistics clear, 13 routing table statistics display, 13
IPv4 BGP
4-byte AS number suppression, 390
basic configuration, 326 basic IPv4 BGP network configuration, 326
BGP+IGP route redistribution, 331
COMMUNITY configuration, 345 ,
confederation configuration, 357
default route advertisement (peer/peer group),
dynamic peer configuration, 333
fake AS number advertisement, 371
642
keepalive interval+hold time configuration,
link state (LS) configuration, 463
load balancing configuration, 408
local AS number appearance, 369
manual soft reset configuration, 396
optimal route advertisement, 301
ORIGINATOR_ID attribute ignore, 348
path selection configuration, 383
peer keychain authentication, 417
private AS number removal, 373
received route preferred value, 367
route distribution filtering policy, 303
route reception filtering policy, 314
route reflector configuration, 355
route summarization (manual), 299
routes received (peer/peer group), 312
session establishment disable, 391
session state change logging, 320
TCP connection source address, 294
IPv4 IS-IS
IPv6
about OSPFv3, 517 comparison of OSPFv3 with OSPFv2, 517
EBGP peer group configuration (IPv6
EBGP peer group configuration (IPv6 unicast
EBGP peer protection (low memory
643
EBGP session establishment (multiple hop), 387
IBGP peer group configuration (IPv6 multicast
IBGP peer group configuration (IPv6 unicast
IP routing FIB route max lifetime, 6
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
OSPFv3 area configuration (NSSA), 521 ,
OSPFv3 area configuration (stub), 520 ,
OSPFv3 DD packet ignore MTU check, 531
OSPFv3 DR election configuration, 554
OSPFv3 inter-area route summarization, 524
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 interface DR priority, 530
OSPFv3 interface packet send/receive disable,
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
OSPFv3 LSA generation interval, 529
OSPFv3 LSA transmission delay, 529
OSPFv3 neighbor state change logging, 542
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
OSPFv3 received route filtering, 525
OSPFv3 route redistribution, 527 ,
OSPFv3 route summarization, 560
OSPFv3 SPF calculation interval, 529
policy-based routing.
See
prefix list configuration, 589
provider edge.
See
See also
routing policy ACLs, 587 routing policy configuration, 587 ,
routing policy configuration (IPv6 route
routing policy prefix list, 587
routing table display, 14 routing table maintain, 14
routing table statistics clear, 15 routing table statistics display, 15
setting OSPFv3 packet timers, 528
IPv6 BGP
4-byte AS number suppression, 390
basic configuration, 339 basic IPv6 BGP network configuration, 339
default route advertisement (peer/peer group),
fake AS number advertisement, 371
keepalive interval+hold time configuration,
local AS number appearance, 369
manual soft reset configuration, 396
optimal route advertisement, 301
ORIGINATOR_ID attribute ignore, 348
peer keychain authentication, 417
private AS number removal, 373
received route preferred value, 367
route distribution filtering policy, 303
route reception filtering policy, 314
route summarization (manual), 300
routes received (peer/peer group), 312
session establishment disable, 391
session state change logging, 320
TCP connection source address, 294
IPv6 IS-IS
IPv6 PBR
interface configuration (packet type-based), 584
IPv6 packet forwarding process, 576
local configuration (packet type-based), 583
logging feature enable, 582 maintain, 582
match mode/node clause relationship, 577
node action configuration, 579
IPv6 static routing
BFD configuration (direct next hop), 487
BFD configuration (indirect next hop), 490
BFD control packet mode (direct next hop), 484 ,
BFD control packet mode (indirect next hop), 484
644
BFD echo packet mode configuration
default route configuration, 493
route configuration, 483 route deletion, 483
IS-IS
authentication (neighbor relationship), 200
authentication (routing domain), 202
authentication configuration, 229
controlling adjacency establishment and maintenance based on BFD session state,
CSNP packet send interval, 184
default route advertisement, 179
DIS election configuration, 221
enabling IS-IS to advertise the maximum link
FRR backup next hop configuration (LFA
FRR backup path selection policy priority
FRR BFD enable (control packet mode), 207 ,
FRR configuration (routing policy), 206
hello packet send interval, 184
interface hello packet send enable, 189
interface P2P network type configuration, 172
interface packet send/receive disable, 189
645
link state info advertisement to BGP, 183
LSP-calculated route filtering, 181
multi-instance processes configuration, 172 ,
neighbor state change logging, 197
nonstop routing (NSR) configuration, 203 ,
P2P interface hello packet source address check,
PIC BFD control packet mode enable, 200
PIC BFD echo packet mode enable, 200
PIC configuration restrictions, 199
point-to-point network type, 163
prefix suppression enable, 199
redistributed route filtering, 182
remote LFA FRR configuration, 209 ,
route control configuration, 174
route convergence priority, 193
route leaking configuration, 182
setting interface cost upon LSDB overload, 194
system ID > host name mapping, 196
ISPF
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed,
K keepalive
BGP route update interval, 308
keychain
IPv4 BGP peer keychain authentication, 417
IPv6 BGP peer keychain authentication, 417
L label
BGP label allocation mode, 406
BGP MPLS local label update delay, 320
IP routing RIB label max lifetime, 5
large-scale BGP network configuration
leaking
level
EBGP peer protection (level 2 threshold
Level-1
IS-IS ATT bit Level-1 LSP, 195 ,
limiting
BGP route sending rate configuration, 307
BGP routes received (peer/peer group)(IPv4),
BGP routes received (peer/peer group)(IPv6),
link
BGP link state (LS) configuration, 456
EBGP direct connection after link failure, 388
IPv4 BGP link state (LS) configuration, 463
IS-IS link state info advertisement to BGP, 183
OSPF basics configuration, 130
OSPF BGP advertisement of link state
OSPF virtual link configuration, 146
link bandwidth
BGP attribute configuration, 317
list
routing policy AS_PATH list, 587 ,
routing policy COMMUNITY list, 587 ,
routing policy prefix list, 587
routing policy RD list, 593 routing policy tag list, 593
LLDP
DCN LLDP frame ARP entry enable, 609
DCN LLDP frame source MAC address, 608
DCN LLDP management address advertisement,
See also
IP routing ECMP enhanced mode, 7 , 7
IPv4 BGP load balancing configuration, 408
load sharing
IP routing IPv4 load sharing (bandwidth-based), 4
IP routing load sharing configuration, 3
IP routing load sharing configuration
(source+destination address based), 15
IP routing load sharing mode, 3
local
BGP default local preference, 368
BGP local AS number appearance, 369
BGP local network injection, 296
BGP LOCAL_PREF path attribute, 261
BGP MPLS local label update delay, 320
IPv6 PBR local configuration, 581
646
IPv6 PBR local configuration (packet
local PBR configuration (packet type-based),
logging
BGP route flapping logging, 321
BGP session state change logging, 320
IS-IS neighbor state change, 197
OSPF neighbor state change, 125
OSPFv3 log max number setting, 542
OSPFv3 neighbor state change logging, 542
loop
next hop recursion loop suppression, 10
next hop recursion loop suppression
RIP routing loop prevention, 34
LS
BGP link state (LS) AS number, 457
BGP link state (LS) configuration, 456
BGP link state (LS) route reflection, 456
BGP link state (LS) router ID, 457
LSA
IPv4 BGP link state (LS) configuration, 463
generation/advertisement/reception control,
OSPF exit overflow interval, 103
OSPF LSA arrival interval, 102
OSPF LSA generation interval, 103
OSPF LSA retransmission packet timer, 100
OSPF LSA transmission delay, 101
OSPF LSDB external LSAs max, 106
OSPF outbound LSA filtering (specified
OSPFv3 inter-area-prefix LSA, 517
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 inter-area-router LSA, 517
OSPFv3 intra-area-prefix LSA, 517
OSPFv3 LSA generation interval, 529
OSPFv3 LSA transmission delay, 529
LSAck
LSDB
OSPF LSDB external LSAs max, 106
LSP
setting interface cost upon LSDB overload, 194
IS-IS ATT bit Level-1 LSP, 195 ,
IS-IS LSP fragment extension, 190
LSR
IS-IS route summarization, 179
LSU
M
MAC addressing
DCN LLDP frame source MAC address, 608
maintaining
basic BGP network configuration, 323
large-scale BGP network configuration, 350
managing
BGP large scale network management, 267
manual
BGP route summarization (IPv4), 299
BGP route summarization (IPv6), 300
647
mapping
IS-IS system ID > host name mapping, 196
IS-IS system ID > host name mapping
matching
IPv6 PBR node match criteria, 579
routing policy if-match clause, 587 ,
MD5
BGP peer MD5 authentication, 415
MED
BGP attribute configuration, 375
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
memory
EBGP peer protection (low memory
message
RIPv1 message zero field check enable, 52
RIPv2 message authentication configuration,
metric
RIP additional routing metric configuration, 39
RIP interface additional metric configuration,
MIB
RIPng routing metric configuration, 496
mode
IPv6 static route BFD control packet mode
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IPv6 static route BFD echo packet mode, 485
static routing BFD control packet mode (direct
static routing BFD control packet mode (indirect
20 static routing BFD echo packet mode, 20
See also
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP FRR configuration, 442
IPv4 BGP GR configuration, 437
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
IPv6 BGP FRR configuration, 450
supported address families, 270
MPLS
IPv6 BGP 6PE configuration, 466
MPLS local IFNET tunnel establishment, 407
MPU
MTR
MTU
OSPF DD packet interface MTU, 105
OSPFv3 DD packet ignore MTU check, 531
multicast
EBGP peer group configuration (IPv4 multicast
EBGP peer group configuration (IPv6 multicast
IBGP peer group configuration (IPv4 multicast
648
IBGP peer group configuration (IPv6 multicast
RIPng basic configuration, 495
multicast BGP
IPv4 BGP dynamic peer configuration, 333
Multiprotocol Extensions for BGP-4.
See
N naming
IS-IS system ID > host name mapping, 196
NBMA
OSPF interface network type, 93
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
neighbor
IS-IS authentication (neighbor relationship),
IS-IS neighbor state change logging, 197
OSPF neighbor state change logging, 125
OSPF outbound LSAs (specified neighbor),
RIP neighbor specification, 39
neighbor discovery (ND)
about OSPFv3, 517 comparison of OSPFv3 with OSPFv2, 517
OSPFv3 area configuration (NSSA), 551
OSPFv3 area configuration (stub), 546
OSPFv3 DR election configuration, 554
OSPFv3 IPsec profile configuration, 571
OSPFv3 neighbor state change logging, 542
NET
OSPFv3 route redistribution, 557
IS-IS network layer information, 161
network
about IPv6 static route BFD, 484
649
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed, 532
advertising only the global unicast address in the
applying BGP RPKI validation state to optimal
basic BGP network building (IPv6 multicast), 276 basic BGP network building (IPv6 unicast), 276
BGP 4-byte AS number suppression, 390
BGP Additional Paths feature, 399
BGP AS number quantity threshold setting, 375
BGP AS number substitution, 371
BGP community configuration, 345
BGP confederation settings, 349
BGP default local preference, 368
BGP default route advertisement (peer/peer
BGP fake AS number advertisement, 371
BGP IGP route redistribution, 297
BGP keepalive interval+hold time configuration,
BGP label allocation mode, 406
BGP link bandwidth attribute, 317
BGP link state (LS) AS number, 457
BGP link state (LS) configuration, 456
BGP link state (LS) route reflection, 456
BGP link state (LS) router ID, 457
BGP local network injection, 296
BGP MPLS local label update delay, 320
BGP optimal route advertisement, 301
BGP optimal route selection delay, 400
BGP peer keychain authentication, 417
BGP peer MD5 authentication, 415
BGP private AS number removal, 373
BGP route advertisement delay, 309
BGP route flapping logging, 321
BGP route update interval, 308
BGP routes received (peer/peer group), 312
BGP RPKI connection parameters, 418
BGP RPKI validation state advertisement, 421
BGP session establishment disable, 391
BGP session state change logging, 320
BGP SNMP notification enable, 322
BGP suboptimal route flush to RIB, 406
BGP TCP connection source address, 294
configuring the next hop type selection rule for
DCN LLDP frame ARP entry enable, 609
DCN LLDP frame source MAC address, 608
DCN LLDP management address
DCN NE ID+NE IP configuration, 606
delay time for responding to recursive next
dynamic host name mapping configuration,
EBGP peer protection (low memory
EBGP session establishment (multiple hop),
650 enabling IS-IS to advertise the maximum link cost
entity title.
Use
extended BGP features, 454 , 454
flushing route attribute information from RIB to
interface PBR configuration (packet
interface PBR configuration (packet type-based),
IP routing active route max number, 12
IP routing dynamic routing protocols, 1
IP routing ECMP enhanced mode, 7 , 7
IP routing extension attribute redistribution, 3
IP routing FIB route max lifetime, 6
IP routing inter-protocol FRR, 8
IP routing IPv4 load sharing (bandwidth-based), 4
IP routing load sharing configuration, 3
IP routing load sharing configuration
(source+destination address based), 15
IP routing load sharing mode, 3
IP routing policy-based recursive lookup, 9
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
IP routing route preference, 2
IP routing route redistribution, 3
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP dynamic peer configuration, 333
IPv4 BGP FRR configuration, 442
IPv4 BGP GR configuration, 437
IPv4 BGP link state (LS) configuration, 463
IPv4 BGP received route preferred value, 367
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP RPKI configuration, 423
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP 6PE configuration, 466
IPv6 BGP basic configuration, 339
IPv6 BGP BFD configuration, 446
IPv6 BGP FRR configuration, 450
IPv6 BGP received route preferred value, 367
IPv6 BGP RPKI configuration, 426
IPv6 IS-IS basic configuration, 249
IPv6 IS-IS BFD configuration, 254
IPv6 IS-IS FRR configuration, 256
IPv6 PBR interface configuration, 581
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 581
IPv6 PBR local configuration (packet
IPv6 PBR node match criteria, 579
IPv6 PBR policy configuration, 578
IPv6 PBR+Track collaboration, 577
IPv6 static route BFD configuration, 484
IPv6 static route BFD control packet mode
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IPv6 static route BFD echo packet mode, 485
IPv6 static route configuration, 483
IPv6 static route deletion, 483
IPv6 static routing basic configuration, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop),
IS-IS authentication (area), 201
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 202
IS-IS basic configuration, 170
IS-IS basics configuration, 216
IS-IS DIS election configuration, 221
IS-IS FRR backup path selection policy priority,
651
IS-IS hello packet send interval, 184
IS-IS interface DIS priority, 187
IS-IS interface hello packet send, 189
IS-IS interface P2P network type, 172
IS-IS interface packet send/receive, 189
IS-IS interface tag value, 188
IS-IS link state info advertisement to BGP, 183
IS-IS LSP fragment extension, 190
IS-IS LSP generation interval, 185
IS-IS LSP receiving interval, 186
IS-IS LSP refresh interval, 185
IS-IS LSP sending interval, 186
IS-IS multi-instance processes configuration, 245
IS-IS neighbor state change logging, 197
IS-IS network optimization, 184
IS-IS PIC BFD control packet mode, 200
IS-IS PIC BFD echo packet mode, 200
IS-IS point-to-point type, 163
IS-IS remote LFA FRR configuration, 241
IS-IS route convergence priority, 193
IS-IS route redistribution, 225
IS-IS route update suppression, 192
IS-IS SPF calculation interval, 186
IS-IS system ID > host name mapping, 196
large-scale BGP network configuration, 344 , 344
local PBR configuration (packet type-based), 477
next hop recursion loop suppression, 10
next hop recursion loop suppression
OSPF area configuration (NSSA), 91 ,
OSPF area configuration (stub), 91 ,
OSPF basics configuration, 130
OSPF BFD detection configuration
OSPF BFD detection configuration
OSPF BGP advertisement of link state
OSPF DD packet interface MTU, 105
OSPF DR election configuration, 142
OSPF exit overflow interval, 103
OSPF FRR backup path selection policy
OSPF GTSM configuration (area view), 124
OSPF GTSM configuration (interface view),
OSPF host route advertisement, 100
OSPF inter-area route summarization, 95
OSPF interface max packet length, 105
OSPF interface network type (broadcast), 93
OSPF interface network type (NBMA), 93
OSPF interface network type (P2MP), 94
OSPF interface network type (P2P), 94
OSPF interface packet send/receive disable,
OSPF logging and SNMP notifications, 125
OSPF LSA arrival interval, 102
OSPF LSA generation interval, 103
OSPF LSA generation/advertisement/reception control,
OSPF LSA transmission delay, 101
OSPF LSDB external LSAs max, 106
652
OSPF neighbor state change logging, 125
OSPF outbound LSA filtering (on interface), 106
OSPF outbound LSA filtering (specified neighbor),
OSPF outgoing packet DSCP value, 105
OSPF received route filtering, 96
OSPF RFC 1583 compatibility, 110
OSPF route redistribution (another routing
OSPF route redistribution (default route), 99
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF SPF calculation interval, 102
OSPF summary network discard route, 98
OSPF virtual link configuration, 146
OSPFv3 area configuration (NSSA), 521 ,
OSPFv3 area configuration (stub), 520 ,
OSPFv3 DD packet ignore MTU check, 531
OSPFv3 DR election configuration, 554
OSPFv3 inter-area route summarization, 524
OSPFv3 Inter-Area-Prefix LSA filtering, 525
OSPFv3 interface DR priority, 530
OSPFv3 interface packet send/receive
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
OSPFv3 log max number setting, 542
OSPFv3 logging and SNMP notifications, 542
OSPFv3 LSA generation interval, 529
OSPFv3 LSA transmission delay, 529
OSPFv3 neighbor state change logging, 542
OSPFv3 network management, 543
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
OSPFv3 outgoing packet DSCP value, 531
OSPFv3 prefix suppression, 532
OSPFv3 received route filtering, 525
OSPFv3 route redistribution, 527 ,
OSPFv3 route summarization, 560
OSPFv3 SPF calculation interval, 529
permitting BGP routes with only tunnel next hops to participate in optimal route selection,
preferring BGP routes of specific next hop
type during optimal route selection, 382
653
prioritized withdrawal of specific routes, 303
prioritized withdrawal of the default route, 302
RIP additional routing metric configuration, 39
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
detection/specific destination), 69
RIP BFD single-hop echo detection, 67
RIP default route advertisement, 41
RIP host route reception disable, 41
RIP interface additional metric configuration, 59
RIP interface advertisement control, 37 ,
RIP interface reception control, 37 ,
RIP network management configuration, 47
RIP outgoing packet DSCP value, 46
RIP packet send rate configuration, 45
RIP poison reverse configuration, 44
RIP preference configuration, 42
RIP received/redistributed route filtering, 42
RIP route control configuration, 39
RIP route redistribution configuration, 43 ,
RIP routing loop prevention, 34
RIP security configuration, 52
RIP split horizon configuration, 44
RIP summary route advertisement configuration,
RIP triggered update interval configuration, 45
RIP update source IP address check, 53
RIPng basic configuration, 495 ,
RIPng default route advertisement, 497
RIPng FRR configuration, 502 ,
RIPng IPsec profile application, 503
RIPng network optimization, 498
RIPng packet and advertisement, 494
RIPng packet zero field check, 503
RIPng received/redistributed route filtering,
RIPng route redistribution, 498
RIPng route redistribution configuration, 508
RIPng route summarization, 496
RIPng routing metric configuration, 496
RIPng timer configuration, 498
RIPng triggered update send interval, 500
RIPv1 message zero field check, 52
RIPv2 message authentication configuration,
RIPv2 route summarization configuration, 40
routing policy apply clause, 596
routing policy AS_PATH list, 589
routing policy COMMUNITY list, 592
routing policy configuration, 593
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 598
routing policy if-match clause, 594
routing policy RD list, 593 routing policy tag list, 593
setting interface cost upon LSDB overload,
setting OSPFv3 packet timers, 528
split horizon and poison reverse configuration,
static route deletion, 18 static route group configuration, 18
static routing basic configuration, 23
static routing BFD, 19 static routing BFD configuration, 19
static routing BFD configuration (direct next
static routing BFD configuration (indirect next
static routing BFD control packet mode (direct
static routing BFD control packet mode (indirect
20 static routing BFD echo packet mode, 20
static routing configuration, 17
static routing FRR, 21 static routing FRR configuration, 21 ,
update suppression during route flaps
network element (NE)
DCN NE ID+NE IP configuration, 606
network management
about IPv6 static routing, 483
comparison of OSPFv3 with OSPFv2, 517
IP routing configuration, 1 , 1 ,
IPv4 prefix list configuration, 589
IPv6 default route configuration, 493
IPv6 IS-IS configuration, 169 ,
IPv6 prefix list configuration, 589
IPv6 static routing configuration, 483 ,
routing policy configuration, 587 ,
static routes, 17 static routing configuration, 17 ,
static routing default route configuration, 33
next hop
recursion loop suppression configuration, 10 , 10
NEXT_HOP
BGP attribute configuration, 365
654
nexthop configuring the next hop type selection rule for
permitting BGP routes with only tunnel next hops to participate in optimal route selection,
preferring BGP routes of specific next hop
type during optimal route selection, 382
NMS
NO_ADVERTISE
BGP COMMUNITY path attribute, 261
NO_EXPORT
BGP COMMUNITY path attribute, 261
NO_EXPORT_SUBCONFED
BGP COMMUNITY path attribute, 261
node
IPv6 PBR node match criteria, 579
IPv6 PBR+Track collaboration, 577
routing policy apply clause, 587 ,
routing policy continue clause, 587 ,
routing policy deny match, 587 routing policy if-match clause, 587 ,
routing policy permit match, 587
non-IETF
nonstop routing (NSR)
notifying
BGP SNMP notification enable, 322
NSAP
NSSA
OSPFv3 area configuration, 551
OSPFv3 area configuration (NSSA), 521
number
BGP 4-byte AS number suppression, 390
BGP AS number substitution, 371
BGP fake AS number advertisement, 371
BGP first AS number of EBGP route update
BGP local AS number appearance, 369
BGP private AS number removal, 373
O
OAM
open
Open Shortest Path First.
Use
Open Shortest Path First version 3.
Use
optimal
configuring the next hop type selection rule for
IP routing FIB table optimal routes, 1
permitting BGP routes with only tunnel next hops
to participate in optimal route selection, 381
preferring BGP routes of specific next hop type
during optimal route selection, 382
optimal route selection
applying BGP RPKI validation state, 420
optimizing
ORIGIN
655
See also
accelerating OSPF convergence speed, 107
advanced OSPF feature configuration, 110
area configuration (NSSA), 91 ,
area configuration (stub), 91 ,
authentication configuration, 122
BFD control packet mode FRR configuration,
BFD detection configuration (bidirectional
BFD detection configuration (single-hop echo),
BFD echo packet mode FRR configuration,
BGP advertisement of link state information,
DD packet interface MTU add, 105
DR election configuration, 142
dynamic host name mapping configuration,
FRR backup next hop specification (routing
FRR backup path selection policy priority
GTSM configuration (area view), 124
656
GTSM configuration (interface view), 124
inter-area route summarization, 95
interface max packet length, 105
interface network type configuration (broadcast),
93 interface network type configuration (NBMA), 93
interface network type configuration (P2MP), 94 interface network type configuration (P2P), 94
interface packet send/receive disable, 104
logging and SNMP notifications, 125 logging feature, 125
LSA generation/advertisement/reception control,
LSU transmit rate configuration, 103
neighbor state change logging, 125
network management configuration, 126
network type configuration, 93
nonstop routing (NSR) configuration, 114 ,
outbound LSA filtering (on interface), 106 outbound LSA filtering (specified neighbor), 106
outgoing packet DSCP value configuration, 105
prefix priority configuration, 108 prefix suppression configuration, 108
received route filtering configuration, 96
redistributed route summarization, 95
remote LFA FRR configuration, 117
restrictions and guidelines, 90
route control configuration, 95
route redistribution (another routing protocol),
route redistribution (default route), 99
route redistribution configuration, 133
route summarization configuration, 134
stub router configuration, 110
summary network discard route, 98
totally NSSA area, 82 totally stub area, 82
troubleshoot configuration, 158
troubleshoot incorrect routing information, 159
troubleshoot no neighbor relationship
Type-3 LSA filtering configuration, 96
update suppression during route flaps
virtual link configuration, 92 ,
OSPF network partition
OSPF network type
restrictions and guidelines, 93
See also
accelerating convergence speed, 532
area configuration (NSSA), 521 ,
area configuration (stub), 520 ,
area parameter configuration, 520 areas, 520
authentication configuration (area), 540 authentication configuration (interface), 540
bandwidth reference value configuration, 526
BFD control packet mode for FRR
BFD echo packet mode for FRR configuration,
DD packet ignore MTU check, 531
DR election configuration, 554
657
FRR backup next hop calculation (LFA algorithm),
FRR backup next hop specification (routing
GR restarter configuration, 535
inter-area route summarization, 524
Inter-Area-Prefix LSA filtering, 525 interface cost configuration, 525 ,
interface packet send/receive disable, 531
IPsec profile application for authenticating
IPsec profile configuration, 571
log max number setting, 542 logging and SNMP notifications, 542
neighbor state change logging, 542
network management configuration, 543
network type configuration (P2MP), 523 network type configuration (P2P), 523
nonstop routing (NSR) configuration, 536 ,
OSPFv3 ISPF configuration, 532
outgoing packet DSCP value configuration, 531 packet parameters, 531
route control configuration, 524
route redistribution (default route), 527
route summarization (on ASBR), 524
stub router configuration, 534
virtual link configuration, 521
P
P2MP
OSPF interface network type, 94
P2P interface hello packet source address check,
OSPF interface network type, 94
OSPFv3 network type (broadcast), 522
OSPFv3 network type (NBMA), 522
OSPFv3 network type (P2MP), 523
OSPFv3 network type (P2P), 523
packet
comparison of OSPFv3 with OSPFv2, 517
dynamic host name mapping configuration,
interface PBR configuration (packet
interface PBR configuration (packet
IP routing configuration, 1 , 1 ,
IP routing dynamic routing protocols, 1
IP routing extension attribute redistribution, 3
IP routing route preference, 2
IP routing route redistribution, 3
IPv6 PBR interface configuration, 581
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 581
IPv6 PBR local configuration (packet
IPv6 PBR logging feature enable, 582
IPv6 PBR policy configuration, 578
IS-IS CSNP packet send interval, 184
IS-IS hello packet send interval, 184
658
IS-IS interface hello packet send, 189
IS-IS interface packet send/receive, 189
IS-IS P2P interface hello packet source address
local PBR configuration (packet type-based), 477
next hop recursion loop suppression configuration,
OSPF basics configuration, 130
OSPF DD packet interface MTU, 105
OSPF exit overflow interval, 103
OSPF interface max packet length, 105
OSPF interface packet send/receive disable, 104
OSPF LSA generation/advertisement/reception
OSPF LSDB external LSAs max, 106
OSPF outgoing packet DSCP value, 105
OSPF RFC 1583 compatibility, 110
OSPF route redistribution configuration, 133
OSPFv3 area configuration (NSSA), 551
OSPFv3 area configuration (stub), 546
OSPFv3 DD packet ignore MTU check, 531
OSPFv3 DR election configuration, 554
OSPFv3 interface packet send/receive disable,
OSPFv3 IPsec profile configuration, 571
OSPFv3 outgoing packet DSCP value, 531
OSPFv3 route redistribution, 557
PBR logging feature enable, 477
RIP BFD configuration (bidirectional control
detection/direct neighbor), 50
RIP BFD configuration (bidirectional control
detection/indirect neighbor), 50
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 49
RIP network management configuration, 47
RIP outgoing packet DSCP value, 46
RIP packet send rate configuration, 45
RIPng packet zero field check, 503
RIPng triggered update send interval, 500
update suppression during route flaps
parameter
IS-IS route convergence priority, 193
IS-IS SPF calculation interval, 186
setting interface cost upon LSDB overload,
path
BGP Additional Paths feature, 399
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
BGP optimal route selection delay, 400
IPv4 BGP Additional Paths feature configuration,
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP path selection configuration, 383
PBR
interface configuration (packet source-IP-based),
interface configuration (packet type-based), 479
IP preference configuration, 580
local configuration (packet type-based), 477
logging feature enable, 477 maintain, 477
node action configuration, 473 ,
outbound PBR, 470 packet forwarding process, 470 policy, 470
PDU
PE peer
IPv6 BGP 6PE configuration, 466
BGP default route advertisement (peer/peer
BGP MED route comparison (confederation
BGP peer keychain authentication, 417
BGP peer MD5 authentication, 415
659
BGP session establishment disable, 391
EBGP peer protection (low memory
IPv4 BGP dynamic peer configuration, 333
IS-IS neighbor state change logging, 197
permitting
BGP local AS number appearance (IPv4), 369
BGP local AS number appearance (IPv6), 369
BGP routes with only tunnel next hops to
participate in optimal route selection, 381
PIC
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed,
OSPF BFD control packet mode, 109
OSPF BFD echo packet mode, 109
OSPFv3 BFD (control packet mode), 533
OSPFv3 BFD (echo packet mode), 534
point-to-point IS-IS network type, 163
poison reverse
RIPng configuration, 499 , 499
policy
BGP route distribution filtering policy, 303
BGP route reception filtering policy, 314
interface PBR configuration (packet
interface PBR configuration (packet
IP routing policy-based recursive lookup, 9
IPv6 PBR interface configuration, 581
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 581
IPv6 PBR local configuration (packet
IPv6 PBR match mode/node clause
IPv6 PBR policy configuration, 578
IS-IS FRR configuration (routing policy), 206
local PBR configuration (packet type-based), 477
OSPF FRR backup next hop (routing policy), 119
OSPFv3 FRR backup next hop (routing policy),
PBR policy specification (interface PBR), 476
PBR policy specification (local PBR), 476
routing policy apply clause, 596
routing policy AS_PATH list, 589
routing policy COMMUNITY list, 592
routing policy configuration, 587 ,
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 598
routing policy if-match clause, 594
routing policy RD list, 593 routing policy tag list, 593
policy-based routing.
Use
preference
IP routing route preference, 2
OSPF route redistribution (another routing
OSPF route redistribution (default route), 99
preferring
BGP default local preference, 368
BGP received route preferred value, 367
IS-IS preference specification, 177
prefix
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed, 532
660
OSPFv3 prefix suppression, 532
routing policy prefix list, 587
Prefix Independent Convergence.
Use
prerequisites
RIB nonstop routing (NSR) configuration, 7
priority
IS-IS interface DIS priority, 187
IS-IS route convergence priority, 193
OSPF prefix priority configuration, 108
OSPFv3 interface DR priority, 530
procedure
accelerating OSPF convergence speed, 107
accelerating OSPFv3 convergence speed,
adding OSPF DD packet interface MTU, 105
advertising BGP default route (peer/peer
advertising BGP default route (peer/peer
advertising BGP fake AS number (IPv4), 371 advertising BGP fake AS number (IPv6), 371
advertising BGP optimal route (IPv4 unicast),
advertising BGP optimal route (IPv6 unicast),
advertising BGP RPKI validation state, 421
advertising DCN LLDP management address,
advertising IS-IS default route, 179
advertising IS-IS link state info to BGP, 183
advertising only the global unicast address in
the NEXT_HOP attribute (IPv4), 366
advertising only the global unicast address in
the NEXT_HOP attribute (IPv6), 366
advertising OSPF host route, 100
advertising OSPF link state information to
advertising RIP default route, 41
advertising RIPng default route, 497
advertising RIPv2 summary route, 40
applying BGP RPKI validation state to optimal
applying OSPFv3 IPsec profile for
authenticating OSPFv3 packets, 540
applying RIPng IPsec profile, 503
applying RIPng IPsec profile (to a process),
applying RIPng IPsec profile (to an interface),
building basic BGP network (IPv4 multicast),
661
building basic BGP network (IPv4 unicast), 275
building basic BGP network (IPv6 multicast), 276 building basic BGP network (IPv6 unicast), 276
configuring bandwidth reference value, 526
configuring basic IPv4 BGP network, 326
configuring basic IPv6 BGP network, 339
configuring BGP 6PE, 459 configuring BGP 6PE basics, 459
configuring BGP Additional Paths feature, 399
configuring BGP AIGP attribute, 378
configuring BGP AS number substitution (IPv4),
configuring BGP AS number substitution (IPv6),
configuring BGP AS_PATH attribute, 369
configuring BGP BFD (IPv4), 432 configuring BGP BFD (IPv6), 432
configuring BGP COMMUNITY (IPv4), 345 configuring BGP COMMUNITY (IPv6), 345
configuring BGP confederation compatibility, 350
configuring BGP confederation settings, 349
configuring BGP default local preference (IPv4),
configuring BGP default local preference (IPv6),
configuring BGP FRR (IPv4 unicast address), 433 configuring BGP FRR (IPv6 unicast address), 433
configuring BGP GTSM (IPv4), 416 configuring BGP GTSM (IPv6), 416
configuring BGP keepalive interval+hold time,
configuring BGP link bandwidth attribute (IPv4),
configuring BGP link bandwidth attribute (IPv6),
configuring BGP link state (LS), 456
configuring BGP link state (LS) route reflection,
configuring BGP Monitoring Protocol (BMP), 454
configuring BGP MPLS local label update delay,
configuring BGP NEXT_HOP attribute (IPv4), 365 configuring BGP NEXT_HOP attribute (IPv6), 365
configuring BGP optimal route selection delay,
configuring BGP peer flap dampening, 403
configuring BGP route dampening (IPv4), 344
configuring BGP route dampening (IPv6), 344
configuring BGP route distribution filtering
configuring BGP route distribution filtering
configuring BGP route preference (IPv4), 363 configuring BGP route preference (IPv6), 363
configuring BGP route reception filtering
configuring BGP route reception filtering
configuring BGP route summarization
configuring BGP route summarization
configuring BGP route update delay, 307
configuring BGP route update interval (IPv4),
configuring BGP route update interval (IPv6),
configuring BGP RPKI connection parameters,
configuring BGP soft reset, 393
configuring BGP soft reset manually (IPv4),
configuring BGP soft reset manually (IPv6),
configuring BGP SoO attribute (IPv4), 316 configuring BGP SoO attribute (IPv6), 316
configuring DCN LLDP frame source MAC
configuring DCN NE ID+NE IP, 606
configuring dynamic host name mapping, 111 ,
configuring EBGP peer group (IPv4 multicast
configuring EBGP peer group (IPv4 unicast
configuring EBGP peer group (IPv6 multicast
configuring EBGP peer group (IPv6 unicast
configuring extended BGP features, 454 , 454
configuring IBGP peer group (IPv4 multicast
662 configuring IBGP peer group (IPv4 unicast
configuring IBGP peer group (IPv6 multicast
configuring IBGP peer group (IPv6 unicast
configuring interface PBR (packet
configuring interface PBR (packet type-based),
configuring inter-protocol FRR, 8
configuring IP routing load sharing
(source+destination address based), 15
configuring IP routing load sharing mode, 3
configuring IP routing policy-based recursive
configuring IP routing RIB NSR, 7
configuring IPv4 BGP Additional Paths feature,
configuring IPv4 BGP basics, 326
configuring IPv4 BGP COMMUNITY, 352
configuring IPv4 BGP confederation, 357
configuring IPv4 BGP dynamic peer, 333
configuring IPv4 BGP link state (LS), 463
configuring IPv4 BGP load balancing, 408
configuring IPv4 BGP path selection, 383
configuring IPv4 BGP route reflector, 355
configuring IPv4 BGP route summarization, 336
configuring IPv4 BGP RPKI, 423
configuring IPv4 BGP+IGP route redistribution,
configuring IPv6 BGP basics, 339
configuring IPv6 BGP IPsec, 418
configuring IPv6 BGP RPKI, 426
configuring IPv6 IS-IS basics, 249
configuring IPv6 IS-IS BFD, 254
configuring IPv6 IS-IS FRR, 256
configuring IPv6 IS-IS MTR, 173
581 configuring IPv6 PBR interface, 581 ,
configuring IPv6 PBR interface (packet
configuring IPv6 PBR local, 581 , 581
configuring IPv6 PBR local (packet
configuring IPv6 PBR node action, 579
configuring IPv6 PBR policy, 578
configuring IPv6 static route, 483
configuring IPv6 static route BFD, 484
configuring IPv6 static route BFD control
packet mode (direct next hop), 484 , 484
configuring IPv6 static route BFD control
packet mode (indirect next hop), 484 , 484
configuring IPv6 static route BFD echo packet
mode, 485 configuring IPv6 static routing basics, 485
configuring IPv6 static routing BFD (direct
configuring IPv6 static routing BFD (indirect
configuring IS-IS ATT bit, 195
configuring IS-IS authentication, 229
configuring IS-IS authentication (area), 201
configuring IS-IS authentication (neighbor
configuring IS-IS authentication (routing
configuring IS-IS basics, 170 ,
configuring IS-IS DIS election, 221
configuring IS-IS ECMP routes max, 178
configuring IS-IS FRR (routing policy), 206
configuring IS-IS FRR backup next hop (LFA
configuring IS-IS interface DIS priority, 187
configuring IS-IS interface P2P network type,
configuring IS-IS interface tag value, 188
configuring IS-IS LFA FRR, 205
configuring IS-IS link cost, 174
configuring IS-IS LSP-calculated route filtering,
configuring IS-IS multi-instance processes,
configuring IS-IS network management, 197
configuring IS-IS redistributed route filtering,
configuring IS-IS remote LFA FRR, 209 ,
configuring IS-IS route control, 174
configuring IS-IS route convergence priority,
663
configuring IS-IS route leaking, 182
configuring IS-IS route redistribution, 180
configuring IS-IS route summarization, 179
configuring IS-IS route update suppression, 192
configuring IS-IS system ID > host name mapping,
configuring IS-IS system ID > host name mapping
configuring Large-scale BGP network
configuring local PBR (packet type-based), 477
configuring next hop recursion loop suppression,
configuring OSPF area (NSSA), 91 ,
configuring OSPF area (stub), 91 ,
configuring OSPF authentication (area), 123 configuring OSPF authentication (interface), 123
configuring OSPF bandwidth reference value, 97
configuring OSPF BFD detection (bidirectional
configuring OSPF BFD detection (single-hop
configuring OSPF DR election, 142
configuring OSPF FRR backup next hop (routing
configuring OSPF FRR backup next hop
calculation (LFA algorithm), 117
configuring OSPF FRR BFD control packet mode,
configuring OSPF FRR BFD echo packet mode,
configuring OSPF GR helper (IETF), 113 configuring OSPF GR helper (non-IETF), 113
configuring OSPF interface cost, 97 , 97
configuring OSPF interface network type
configuring OSPF interface network type (NBMA),
configuring OSPF interface network type (P2MP),
configuring OSPF interface network type
configuring OSPF logging feature, 125
configuring OSPF network management, 126
configuring OSPF network type, 93
configuring OSPF NSR, 114 , 114 ,
configuring OSPF PIC BFD control packet
configuring OSPF PIC BFD echo packet mode,
configuring OSPF prefix priority, 108
configuring OSPF prefix suppression
configuring OSPF prefix suppression (OSPF
configuring OSPF received route filtering, 96 ,
configuring OSPF redistributed route
configuring OSPF remote LFA FRR, 117
configuring OSPF route control, 95
configuring OSPF route redistribution, 133
configuring OSPF route summarization, 134
configuring OSPF stub router, 110
configuring OSPF summary network discard
configuring OSPF Type-3 LSA filtering, 96
configuring OSPF virtual link, 92 ,
configuring OSPFv3 area (NSSA), 521 ,
configuring OSPFv3 area (stub), 520 ,
configuring OSPFv3 area parameter, 520
configuring OSPFv3 authentication, 539
configuring OSPFv3 authentication (area),
configuring OSPFv3 authentication (interface),
configuring OSPFv3 DR election, 554
configuring OSPFv3 FRR backup next hop
configuring OSPFv3 FRR backup next hop
calculation (LFA algorithm), 538 , 538
configuring OSPFv3 FRR BFD control packet
configuring OSPFv3 FRR BFD echo packet
configuring OSPFv3 GR helper, 535
664
configuring OSPFv3 GR restarter, 535
configuring OSPFv3 Inter-Area-Prefix LSA
filtering, 525 configuring OSPFv3 interface cost, 525 ,
configuring OSPFv3 interface DR priority, 530
configuring OSPFv3 IPsec profile, 571
configuring OSPFv3 LSU transmit rate, 530
configuring OSPFv3 network management, 543
configuring OSPFv3 network type, 522
configuring OSPFv3 network type (broadcast),
522 configuring OSPFv3 network type (NBMA), 522
configuring OSPFv3 network type (P2MP), 523 configuring OSPFv3 network type (P2P), 523
configuring OSPFv3 NSR, 536 , 536 ,
configuring OSPFv3 OSPFv3 ISPF, 532 , 532
configuring OSPFv3 packet parameters, 531
configuring OSPFv3 PIC BFD (control packet
configuring OSPFv3 PIC BFD (echo packet
configuring OSPFv3 preference, 526
configuring OSPFv3 prefix suppression
configuring OSPFv3 prefix suppression (OSPFv3
configuring OSPFv3 received route filtering, 525
configuring OSPFv3 route control, 524
configuring OSPFv3 route redistribution, 557
configuring OSPFv3 route redistribution (default
configuring OSPFv3 route summarization, 560
configuring OSPFv3 route summarization (on
configuring OSPFv3 stub router, 534
configuring OSPFv3 virtual link, 521
configuring PBR IP preference, 580
configuring PBR node action, 473 ,
configuring RIP additional routing metric, 39
configuring RIP BFD (bidirectional control
configuring RIP BFD (bidirectional control
detection/direct neighbor), 50
configuring RIP BFD (bidirectional control
detection/indirect neighbor), 50
configuring RIP BFD (single-hop echo
configuring RIP BFD (single-hop echo
detection/specific destination), 49 ,
configuring RIP BFD single-hop echo
configuring RIP interface additional metric, 59
configuring RIP network management, 47
configuring RIP packet send rate, 45
configuring RIP received/redistributed route
configuring RIP route control, 39
configuring RIP route redistribution, 43 ,
configuring RIP split horizon, 44
configuring RIP summary route advertisement,
configuring RIPng, 495 configuring RIPng basics, 495 ,
configuring RIPng FRR, 502 , 502 ,
configuring RIPng packet send rate, 499
configuring RIPng packet zero field check,
configuring RIPng poison reverse, 499
configuring RIPng received/redistributed route
configuring RIPng route control, 496
configuring RIPng route redistribution, 498 ,
configuring RIPng route summarization, 496 configuring RIPng routing metric, 496
configuring RIPng split horizon, 499
configuring RIPv2 message authentication, 53
configuring RIPv2 route summarization, 40
configuring route advertisement delay, 309
configuring routing policy, 593
configuring routing policy (IPv4 route
configuring routing policy (IPv6 route
configuring routing policy apply clause, 596
configuring routing policy AS_PATH list, 589
configuring routing policy COMMUNITY list,
configuring routing policy continue clause, 598
665
configuring routing policy if-match clause, 594
configuring routing policy RD list, 593 configuring routing policy tag list, 593
configuring startup policy for BGP route updates,
configuring static route BFD, 19
configuring static route FRR (auto select backup
configuring static route group, 18
configuring static routing basics, 23
configuring static routing BFD (direct next hop),
configuring static routing BFD (indirect next hop),
configuring static routing BFD control packet
mode (direct next hop), 19 , 19
configuring static routing BFD control packet
mode (indirect next hop), 19 ,
configuring static routing BFD echo packet mode,
configuring static routing FRR, 21 ,
configuring static routing FRR (backup next hop),
configuring update suppression during route flaps,
controlling adjacency establishment and
maintenance based on BFD session state, 204
controlling BGP path selection, 363
controlling IS-IS SPF calculation interval, 186
controlling LSA
generation/advertisement/reception, 106
controlling RIP interface advertisement, 37 ,
controlling RIP interface reception, 37 ,
controlling RIP interface suppression, 37
deleting IPv6 static routes, 483
disabling BGP session establishment (IPv4), 391 disabling BGP session establishment (IPv6), 391
disabling IPv4 next hop recursion loop
disabling IPv6 next hop recursion loop
disabling IS-IS interface packet send/receive, 189
disabling MPLS local IFNET tunnel establishment,
disabling OSPF interface packet send/receive,
disabling OSPFv3 interface packet send/receive,
disabling recursion policy for routes received
from a peer or peer group, 405
disabling RIP host route reception, 41
enabling BGP 4-byte AS number suppression
enabling BGP 4-byte AS number suppression
enabling BGP load balancing (IPv4), 397 enabling BGP load balancing (IPv6), 397
enabling BGP MED route comparison
enabling BGP MED route comparison (diff
enabling BGP MED route comparison
enabling BGP ORF capabilities negotiation,
enabling BGP peer keychain authentication
enabling BGP peer keychain authentication
enabling BGP peer MD5 authentication (IPv4),
enabling BGP peer MD5 authentication (IPv6),
enabling BGP route flapping logging (IPv4),
enabling BGP route flapping logging (IPv6),
enabling BGP route-refresh (IPv4), 394 enabling BGP route-refresh (IPv6), 394
enabling BGP RPKI validation, 420
enabling BGP session state change logging
enabling BGP session state change logging
enabling BGP SNMP notification, 322
enabling DCN automatic report, 607
enabling DCN LLDP frame ARP entry, 609
enabling EBGP direct connections upon link
enabling EBGP session establishment
enabling EBGP session establishment
enabling first-AS-number check for EBGP
enabling IP routing ECMP enhanced mode, 7
Enabling IP routing IPv4 load sharing
666
enabling IPv4 ECMP enhanced mode, 7
enabling IPv6 BGP MED AS route comparison
enabling IPv6 PBR logging feature, 582
enabling IPv6 route fast switchover, 9
enabling IS-IS FRR BFD (control packet mode),
enabling IS-IS FRR BFD (echo packet mode),
enabling IS-IS interface hello packet send, 189
enabling IS-IS LSP flash flooding, 190 enabling IS-IS LSP fragment extension, 190
enabling IS-IS neighbor state change logging,
enabling IS-IS P2P interface hello packet source
enabling IS-IS PIC BFD control packet mode, 200 enabling IS-IS PIC BFD echo packet mode, 200
enabling IS-IS prefix suppression, 199
enabling IS-IS to advertise the maximum link cost
enabling load sharing (symmetric), 4
enabling OSPF (on interface), 90 enabling OSPF (on network), 90
enabling OSPF RFC 1583 compatibility, 110
enabling OSPFv3 neighbor state change logging,
enabling PBR logging feature, 477
enabling prioritized withdrawal of specific routes,
enabling prioritized withdrawal of the default route,
enabling RIP (on interface), 37 enabling RIP (on network), 37
enabling RIP FRR BFD bidirectional control
enabling RIP FRR BFD single-hop echo detection,
enabling RIP poison reverse, 44 , 44 enabling RIP split horizon, 44
enabling RIP update source IP address check, 53
enabling RIPv1 message zero field check, 52
enabling RIPv2 automatic route
enabling static routing FRR BFD echo packet
enhancing IS-IS network security, 200
filtering OSPF outbound LSA (on interface),
filtering OSPF outbound LSAs (specified
flushing BGP suboptimal route to RIB, 406
flushing route attribute information from RIB to
ignoring BGP first AS number of EBGP route
ignoring BGP IGP metrics during optimal route
ignoring BGP ORIGINATOR_ID attribute
ignoring BGP ORIGINATOR_ID attribute
ignoring BGP router IDs during optimal route
ignoring OSPFv3 DD packet MTU check, 531
injecting BGP local network (IPv4), 296 injecting BGP local network (IPv6), 296
limiting BGP routes received (peer/peer
limiting BGP routes received (peer/peer
limiting IS-IS LSP flooding, 191
logging OSPF neighbor state change, 125
maintaining basic BGP network configuration,
maintaining IP load sharing, 5
maintaining IP routing table (IPv4), 12
maintaining IP routing table (IPv6), 14
maintaining large-scale BGP network
maintaining routing policy, 598
optimizing IS-IS networks, 184
OSPF logging and SNMP notifications, 125
667
OSPFv3 logging and SNMP notifications, 542
permitting BGP local AS number appearance
permitting BGP local AS number appearance
permitting BGP routes with only tunnel next hops
to participate in optimal route selection, 381
preferring BGP routes of specific next hop type
during optimal route selection, 382
protecting EBGP peer (low memory
protecting EBGP peer (low memory
redistributing BGP IGP route, 297
removing BGP private AS number from EBGP
peer/peer group update (IPv4), 373
removing BGP private AS number from EBGP
peer/peer group update (IPv6), 373
saving BGP route update (IPv4), 395 saving BGP route update (IPv6), 395
setting BGP AS number quantity threshold, 375
setting BGP outgoing packet DSCP value, 405
setting BGP received route preferred value (IPv4),
setting BGP received route preferred value (IPv6),
setting BGP route sending rate, 307
setting BGP session retry timer (IPv4), 319 setting BGP session retry timer (IPv6), 319
setting interface cost upon LSDB overload, 194
setting IP routing active route max number, 12
setting IP routing FIB route max lifetime, 6
setting IP routing RIB label max lifetime, 5 setting IP routing RIB route max lifetime, 5
setting IPv6 PBR node match criteria, 579
setting IS-IS ATT bit Level-1 LSP, 195 ,
setting IS-IS FRR backup path selection policy
setting IS-IS IS+circuit level, 171
setting IS-IS LSDB overload bit, 193
setting IS-IS LSP generation interval, 185
setting IS-IS LSP max age, 184
setting IS-IS LSP receiving interval, 186
setting IS-IS LSP refresh interval, 185
setting IS-IS LSP sending interval, 186
setting OSPF ECMP routes max, 97
setting OSPF exit overflow interval, 103
setting OSPF FRR backup path selection policy
setting OSPF interface max packet length, 105
setting OSPF LSA arrival interval, 102
setting OSPF LSA generation interval, 103
setting OSPF LSA transmission delay, 101
setting OSPF LSDB external LSAs max, 106
setting OSPF LSU transmit rate, 103
setting OSPF outgoing packet DSCP value,
setting OSPF packet timer, 100
setting OSPFv3 ECMP route max, 526
setting OSPFv3 log max number, 542
setting OSPFv3 LSA generation interval, 529 setting OSPFv3 LSA transmission delay, 529
setting OSPFv3 outgoing packet DSCP value,
setting OSPFv3 packet timers, 528
setting OSPFv3 SPF calculation interval, 529
setting packet parameters, 104
setting PBR node match criteria, 473
setting RIP ECMP route max number, 45
setting RIP outgoing packet DSCP value, 46 setting RIP packet max length, 46
setting RIP triggered update interval, 45
setting RIPng ECMP route max, 499
setting RIPng split horizon and poison reverse,
setting RIPng triggered update send interval,
setting the delay time for responding to
recursive next hop changes, 402
setting the interval for clearing the recursion
setting the interval for clearing the recursion
specifying BGP label allocation mode, 406
specifying BGP link state (LS) AS number,
457 specifying BGP link state (LS) router ID, 457
specifying BGP TCP connection source
specifying BGP TCP connection source
specifying IS-IS CSNP packet send interval,
specifying IS-IS hello multiplier, 188
specifying IS-IS hello packet send interval,
specifying IS-IS preference, 177
specifying OSPF SPF calculation interval, 102
troubleshooting BGP peer connection state, 342
troubleshooting OSPF incorrect routing
troubleshooting OSPF no neighbor relationship
verifying basic BGP network configuration, 323
verifying IP routing table (IPv4), 12
verifying IP routing table (IPv6), 14
verifying IPv6 static routing, 485
verifying large-scale BGP network configuration,
profile
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
protecting
EBGP peer (low memory exemption)(IPv4), 404
EBGP peer (low memory exemption)(IPv6), 404
protocols and standards
IP routing dynamic routing protocols, 1
OSPF RFC 1583 compatibility, 110
668
R rate
receiving
BGP routes received (peer/peer group), 312
IS-IS interface packet send/receive, 189
OSPF interface packet send/receive disable,
OSPF received route filtering, 96
OSPFv3 interface packet send/receive
RIPng received/redistributed route filtering,
recursion
BGP load balancing through route recursion,
BGP route recursion, 266 , 266
disabling recursion policy for routes received
from a peer or peer group, 405
next hop recursion loop suppression, 10
next hop recursion loop suppression
redistributing
IP routing extension attribute redistribution, 3
IP routing route redistribution, 3
IPv4 BGP+IGP route redistribution, 331
IS-IS redistributed route filtering, 182
IS-IS route redistribution, 180 ,
OSPF route (another routing protocol), 98
OSPF route (default route), 99
OSPF route redistribution configuration, 133
OSPFv3 route redistribution, 527
OSPFv3 route redistribution (default route),
RIP received/redistributed route filtering, 42
RIPng received/redistributed route filtering,
RIPng route redistribution, 498
RIPng route redistribution configuration, 508
refreshing
removing
BGP private AS number from EBGP peer/peer
BGP private AS number from EBGP peer/peer
reporting
DCN automatic report enable, 607
resource public key infrastructure (RPKI)
restrictions
BGP 4-byte AS number suppression, 391
BGP EBGP session establishment (multiple hop),
BGP NEXT_HOP attribute configuration, 365
IPv6 static routing BFD echo packet mode
policy-based recursive lookup configuration, 9
restrictions and guidelines
configuring static routing FRR, 21
dynamic host name mapping configuration, 111
FRR backup next hop calculation (LFA algorithm),
inter-protocol FRR configuration, 8
IPv6 PBR interface configuration, 582
IPv6 PBR local configuration, 581
next hop recursion loop suppression, 10
nonstop routing (NSR) configuration, 114
policy specification (interface PBR), 476 policy specification (local PBR), 476
RFC 1583 compatibility (OSPF), 110
RIB
BGP suboptimal route flush to RIB, 406
flushing route attribute information from RIB to
669
IP routing FIB route max lifetime, 6
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
See also
additional routing metric configuration, 39
BFD configuration (bidirectional control
BFD configuration (bidirectional control
detection/direct neighbor), 50
BFD configuration (bidirectional control
detection/indirect neighbor), 50
BFD configuration (single-hop echo
BFD configuration (single-hop echo
detection/specific destination), 49 ,
BFD single-hop echo detection, 67
default route advertisement, 41
FRR BFD bidirectional control detection
FRR BFD single-hop echo detection enable,
FRR configuration restrictions, 51
GR restarter configuration, 47
host route reception disable, 41
interface additional metric configuration, 59
interface advertisement control, 37 ,
interface reception control, 37 ,
IPv6.
See
network management configuration, 47
network optimization, 43 network tuning, 43
nonstop routing (NSR) configuration, 65
nonstop routing (NSR) enable, 48
outgoing packet DSCP value, 46 packet max length, 46
packet send rate configuration, 45
poison reverse configuration, 44 poison reverse enable, 44
received/redistributed route filtering, 42
RIPv1 message zero field check enable, 52
RIPv2 message authentication configuration, 53
RIPv2 route summarization configuration, 40
route control configuration, 39
route redistribution configuration, 43 ,
routing loop prevention, 34 routing metrics, 34
split horizon configuration, 44 split horizon enable, 44
summary route advertisement configuration, 61
triggered update interval configuration, 45
update source IP address check, 53 verify, 53
RIP basics
restrictions and guidelines, 36
See also
default route advertisement, 497
FRR configuration, 502 , 502 ,
FRR configuration restrictions, 502
IPsec profile application, 503
IPsec profile application (to a process), 504
IPsec profile application (to an interface), 504 maintain, 504
network optimization, 498 network tuning, 498
nonstop routing (NSR) configuration, 501 ,
packet send rate configuration, 499
poison reverse configuration, 499
received/redistributed route filtering, 497
670
route redistribution configuration, 498 ,
route summarization, 496 routing metric configuration, 496
split horizon and poison reverse configuration,
499 split horizon configuration, 499
triggered update send interval configuration,
RIPv1
message zero field check enable, 52
RIPv2
automatic route summarization enable, 40
message authentication configuration, 53
route summarization configuration, 40 summary route advertisement, 40
route
about IPv6 static route BFD, 484
about IPv6 static routing, 483
BGP default route advertisement (peer/peer
BGP IGP route redistribution, 297
BGP link state (LS) route reflection, 456
BGP MED route comparison (confederation
BGP MED route comparison (diff ASs), 376
BGP MED route comparison (per-AS), 376
BGP optimal route advertisement, 301
BGP ORIGINATOR_ID attribute ignore, 348
BGP route advertisement delay, 309
BGP route advertisement rules, 265
BGP route distribution filtering policy, 303
BGP route flapping logging, 321
BGP route reception filtering policy, 314
671
BGP route sending rate configuration, 307
BGP route update interval, 308
BGP route-refresh message, 260
BGP routes received (peer/peer group), 312
BGP suboptimal route flush to RIB, 406
enabling first-AS-number check for EBGP routes,
flushing route attribute information from RIB to
IP routing active route max number, 12
IP routing FIB route max lifetime, 6
IP routing FIB table optimal routes, 1
IP routing inter-protocol FRR, 8
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
IP routing route preference, 2
IP routing route redistribution, 3
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 default route configuration, 493
IPv6 route fast switchover enable, 9
IPv6 static route BFD configuration, 484
IPv6 static route BFD control packet mode (direct
IPv6 static route BFD control packet mode
(indirect next hop), 484 , 484
IPv6 static route BFD echo packet mode, 485
IPv6 static route configuration, 483
IPv6 static route deletion, 483
IPv6 static routing basic configuration, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop), 490
IPv6 static routing configuration, 483 ,
IS-IS default route advertisement, 179
IS-IS LSP-calculated route filtering, 181
IS-IS redistributed route filtering, 182
IS-IS route leaking, 182 , 182
IS-IS route redistribution, 180 ,
IS-IS route summarization, 179
next hop recursion loop suppression, 10
next hop recursion loop suppression
OSPF area configuration (NSSA), 140
OSPF area configuration (stub), 137
OSPF host route advertisement, 100
OSPF inter-area route summarization, 95
OSPF received route filtering, 96
OSPF redistributed route summarization, 95
OSPF route redistribution (another routing
OSPF route redistribution (default route), 99
OSPF route redistribution configuration, 133
OSPF route summarization configuration, 134
OSPF summary network discard route, 98
OSPFv3 inter-area route summarization, 524
OSPFv3 received route filtering, 525
OSPFv3 route redistribution, 527 ,
OSPFv3 route redistribution (default route),
OSPFv3 route summarization, 560
OSPFv3 route summarization (on ASBR), 524
prioritized withdrawal of specific routes, 303
prioritized withdrawal of the default route, 302
RIP default route advertisement, 41
RIP host route reception disable, 41
RIP poison reverse configuration, 44
RIP preference configuration, 42
RIP received/redistributed route filtering, 42
RIP route control configuration, 39
RIP route redistribution configuration, 43 ,
RIP split horizon configuration, 44
RIP update source IP address check, 53
RIPng default route advertisement, 497
RIPng received/redistributed route filtering,
RIPng route redistribution, 498
RIPng route redistribution configuration, 508
RIPng route summarization, 496
RIPv1 message zero field check, 52
RIPv2 summary route advertisement, 40
static route deletion, 18 static route group configuration, 18
static routing basic configuration, 23
static routing BFD, 19 static routing BFD configuration, 19
static routing BFD configuration (direct next hop),
static routing BFD configuration (indirect next
static routing configuration, 17 , 17 ,
static routing default route configuration, 33
static routing FRR, 21 static routing FRR configuration, 21 ,
route categories
router
BGP link state (LS) router ID, 457
IS-IS interface P2P network type, 172
router ID
automatic configuration, 84 manual configuration, 84 using global router ID, 84
672
routing
BGP Monitoring Protocol (BMP) configuration,
IPv4 routing table display, 12
IPv4 routing table statistics clear, 13
IPv4 routing table statistics display, 13
IPv6 default route.
See under IPv6 static routing
IPv6 policy-based routing.
See
IPv6 routing table display, 14
IPv6 routing table statistics clear, 15
IPv6 routing table statistics display, 15
IPv6 static routing.
See
policy-based routing.
Use
Routing Information Protocol.
Use
routing policy
RPKI
IPv4 BGP RPKI configuration, 423
IPv6 BGP RPKI configuration, 426
rule
BGP route advertisement rules, 265
S saving
searching
security
IS-IS authentication (area), 201
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 202
OSPF authentication (area), 123
OSPF authentication (interface), 123
OSPFv3 IPsec profile application for
authenticating OSPFv3 packets, 540
OSPFv3 IPsec profile configuration, 571
OSPFv3 prefix suppression, 532
RIPng IPsec profile application, 503
SEL
selecting
BGP load balancing through route selection, 266
sending
IS-IS CSNP packet send interval, 184
IS-IS hello packet send interval, 184
IS-IS interface hello packet send, 189
IS-IS interface packet send/receive, 189
OSPF interface packet send/receive disable, 104
OSPFv3 interface packet send/receive disable,
RIPng triggered update send interval, 500
session
BGP Monitoring Protocol (BMP) configuration,
BGP session establishment disable, 391
BGP session state change logging, 320
EBGP session establishment (multiple hop), 387
setting
BGP AS number quantity threshold, 375
BGP outgoing packet DSCP value, 405
BGP received route preferred value (IPv4), 367
BGP received route preferred value (IPv6), 367
BGP session retry timer (IPv4), 319
BGP session retry timer (IPv6), 319
delay time for responding to recursive next hop
flushing route attribute information from RIB to
interface cost upon LSDB overload, 194
interval for clearing the recursion loop counter
interval for clearing the recursion loop counter
IP routing active route max number, 12
IP routing FIB route max lifetime, 6
IP routing RIB label max lifetime, 5
IP routing RIB route max lifetime, 5
IPv6 PBR node match criteria, 579
IS-IS ATT bit Level-1 LSP, 195 ,
673
IS-IS FRR backup path selection policy priority,
IS-IS LSP generation interval, 185
IS-IS LSP receiving interval, 186
IS-IS LSP refresh interval, 185
IS-IS LSP sending interval, 186
OSPF exit overflow interval, 103
OSPF FRR backup path selection policy
OSPF interface max packet length, 105
OSPF LSA arrival interval, 102
OSPF LSA generation interval, 103
OSPF LSA generation/advertisement/reception control,
OSPF LSA transmission delay, 101
OSPF LSDB external LSAs max, 106
OSPF outgoing packet DSCP value, 105
OSPFv3 LSA generation interval, 529
OSPFv3 LSA transmission delay, 529
OSPFv3 outgoing packet DSCP value, 531
OSPFv3 SPF calculation interval, 529
RIP outgoing packet DSCP value, 46
RIP triggered update interval, 45
RIPng split horizon and poison reverse, 499
RIPng triggered update send interval, 500
SNMP
BGP SNMP notification enable, 322
soft reset
SoO
BGP attribute configuration, 316
source
DCN LLDP frame source MAC address, 608
IP routing load sharing configuration
(source+destination address based), 15
IS-IS P2P interface hello packet source address
RIP source IP address check, 53
speaker
specifying
BGP label allocation mode, 406
BGP link state (LS) AS number, 457
BGP link state (LS) router ID, 457
BGP TCP connection source address, 294
BGP TCP connection source address (IPv4), 294
BGP TCP connection source address (IPv6), 294
IS-IS CSNP packet send interval, 184
IS-IS hello packet send interval, 184
OSPF SPF calculation interval, 102
PBR policy (interface PBR), 476
SPF
IS-IS calculation interval, 186
OSPF SPF calculation interval, 102
OSPFv3 SPF calculation interval, 529
split horizon
RIPng configuration, 499 , 499
state
BGP session state change logging, 320
OSPF neighbor state change logging, 125
static routing.
See
static route group
static routing
BFD configuration (direct next hop), 25
674
BFD configuration (indirect next hop), 27
default route configuration, 33
IPv6.
See
static routing BFD control packet mode (direct
static routing BFD control packet mode
20 static routing BFD echo packet mode, 20
static routing FRR, 21 static routing FRR configuration, 21
stub
OSPF area configuration (stub), 91
OSPFv3 area configuration, 546
OSPFv3 area configuration (stub), 520
substituting
BGP AS number substitution, 371
summarizing
IPv4 BGP route summarization, 336
IS-IS route summarization, 179
OSPF inter-area route summarization, 95
OSPF redistributed route summarization, 95
OSPF route summarization configuration, 134
OSPF summary network discard route, 98
OSPFv3 route summarization, 560
OSPFv3 route summarization (on ASBR), 524
RIPng route summarization, 496
RIPv2 automatic route summarization enable,
RIPv2 route summarization configuration, 40
RIPv2 summary route advertisement, 40
suppressing
BGP 4-byte AS number suppression, 390
next hop recursion loop, 10 , 10
OSPFv3 prefix suppression, 532
symmetric
system
IS-IS system ID > host name mapping, 196
T table
BGP optimal route advertisement, 301
tag
IS-IS interface tag value, 188
TCP
BGP TCP connection source address, 294
IPv4 BGP basic configuration, 326
IPv4 BGP BFD configuration, 438
IPv4 BGP COMMUNITY configuration, 352
IPv4 BGP dynamic peer configuration, 333
IPv4 BGP FRR configuration, 442
IPv4 BGP GR configuration, 437
IPv4 BGP load balancing configuration, 408
IPv4 BGP path selection configuration, 383
IPv4 BGP route reflector configuration, 355
IPv4 BGP route summarization, 336
IPv4 BGP+IGP route redistribution, 331
IPv6 BGP basic configuration, 339
threshold
EBGP peer protection (level 2 threshold), 404
time
IPv6 BGP BFD configuration, 446
IPv6 BGP FRR configuration, 450
timeout
timer
OSPF LSA retransmission packet, 100
RIPng timer configuration, 498
TLV
IPv6 IS-IS basic configuration, 249
IPv6 IS-IS BFD configuration, 254
675
topology
about IPv6 static routing, 483
IPv6 default route configuration, 493
IPv6 static route configuration, 483
IPv6 static route deletion, 483
IPv6 static routing basic configuration, 485
IPv6 static routing BFD (direct next hop), 487
IPv6 static routing BFD (indirect next hop),
IPv6 static routing configuration, 483 ,
Track
static routing configuration, 17
transmitting
trapping
BGP SNMP notification enable, 322
OSPF network management, 126 , 126
OSPFv3 network management, 543
triggered RIP (TRIP)
triggering
RIP triggered update interval, 45
RIPng triggered update send interval, 500
troubleshooting
BGP peer connection state, 342
OSPF incorrect routing information, 159
OSPF no neighbor relationship established,
TTL
tuning
tunnel permitting BGP routes with only tunnel next hops to participate in optimal route selection,
preferring BGP routes of specific next hop
type during optimal route selection, 382
Type 1 external
Type 2 external
U
UDP
RIPng basic configuration, 495 ,
RIPng route redistribution configuration, 508
unicast
BGP FRR configuration (IPv4 unicast address),
BGP FRR configuration (IPv6 unicast address),
EBGP peer group configuration (IPv4 unicast
EBGP peer group configuration (IPv6 unicast
IBGP peer group configuration (IPv4 unicast
IBGP peer group configuration (IPv6 unicast
IP routing dynamic routing protocols, 1
IP routing extension attribute redistribution, 3
IP routing route preference, 2
IP routing route redistribution, 3
updating
BGP MPLS local label update delay, 320
BGP route advertisement delay, 309
BGP route update interval, 308
RIP source IP address check, 53
RIP triggered update interval, 45
RIPng triggered update send interval, 500
V value
BGP outgoing packet DSCP value, 405
676
BGP received route preferred value, 367
verifying
basic BGP network configuration, 323
large-scale BGP network configuration, 350
virtual
OSPF virtual link configuration, 146
VPN
Z zero
RIPng packet zero field check, 503
677
Pobierz
Publiczny link zaktualizowany
Publiczny link do Twojego czatu został zaktualizowany. You may view and manage your chat links after registration here.
Publiczny link do dokumentu
Reklama