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HPE FlexNetwork 5510 HI Switch Series
Layer 3—IP Routing Configuration Guide
Part number: 5200-0077b
Software version: Release 11xx
Document version: 6W102-20171020
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Contents
Configuring basic IP routing ································································ 1
Configuring static routing ··································································· 8
Configuring a default route ······························································· 23
Configuring RIP ············································································· 24
i
Configuring OSPF ·········································································· 60
ii
Configuring IS-IS ·········································································· 125
iii
Configuring BGP ·········································································· 178
iv
v
Configuring PBR ·········································································· 312
Configuring IPv6 static routing ························································ 320
Configuring an IPv6 default route ····················································· 330
Configuring RIPng ········································································ 331
vi
Configuring OSPFv3 ····································································· 347
vii
Configuring IPv6 IS-IS ··································································· 394
Configuring IPv6 PBR ··································································· 405
Configuring routing policies ···························································· 413
viii
Document conventions and icons ···················································· 425
Support and other resources ·························································· 427
ix
Configuring basic IP routing
The term "interface" in this chapter collectively refers to Layer 3 interfaces, including VLAN interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a Layer 3 interface by using the port link-mode route command (see Layer 2—LAN Switching Configuration Guide ).
IP routing directs IP packet forwarding on routers based on a routing table. This chapter focuses on unicast routing protocols. For more information about multicast routing protocols, see IP Multicast
Configuration Guide .
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 .
Table 1 categorizes routes by different criteria.
Table 1 Route categories
Criterion
Destination
Categories
•
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.
Origin
•
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.
To view brief information about a routing table, use the display ip routing-table command.
<Sysname> display ip routing-table
Destinations : 19 Routes : 19
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.0/24 Direct 0 0 1.1.1.1 Vlan1
1.1.1.0/32 Direct 0 0 1.1.1.1 Vlan1
1.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
1.1.1.255/32 Direct 0 0 1.1.1.1 Vlan1
2.2.2.0/24 Static 60 0 12.2.2.2 Vlan2
80.1.1.0/24 OSPF 10 2 80.1.1.1 Vlan3
...
A route entry includes the following key items:
•
Destination —IP address of the destination host or network.
•
Mask —Mask length of the IP address.
1
•
Pre —Preference of the route. Among routes to the same destination, the route with the highest preference is optimal.
•
Cost —If multiple routes to a destination have the same preference, the one with the smallest cost is the optimal route.
•
NextHop —Next hop.
•
Interface —Output interface.
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
Routing algorithm
Destination address type
IP version
Categories
•
IGPs —Work within an AS. Examples include RIP, OSPF, and IS-IS.
•
EGPs —Work between ASs. The most popular EGP is BGP.
•
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.
•
Unicast routing protocols —Examples include RIP, OSPF, BGP, and IS-IS.
•
Multicast routing protocols —Examples include PIM-SM and PIM-DM.
•
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
Multicast static route
OSPF
IS-IS
Preference
0
1
10
15
2
Route type
Unicast static route
RIP
OSPF ASE
OSPF NSSA
IBGP
EBGP
Unknown (route from an untrusted source)
Preference
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.
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 route that has an indirectly connected next hop, a router must perform route recursion to find the output interface to reach the next hop.
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.
3
The RIB records extended attributes of each routing protocol and redistribution relationships of different routing protocol extended attributes.
Configuring the maximum lifetime for routes and labels in the RIB
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.
The configuration takes effect at the next protocol or RIB process switchover.
To configure the maximum lifetime for routes and labels in the RIB (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
N/A 2. Enter RIB view.
3. Create a RIB IPv4 address family and enter RIB IPv4 address family view. rib address-family ipv4
By default, no RIB IPv4 address family is created.
4. Configure the maximum lifetime for IPv4 routes and labels in the RIB.
protocol protocol lifetime seconds
By default, the maximum lifetime for routes and labels in the RIB is 480 seconds.
To configure the maximum route lifetime for routes and labels in the RIB (IPv6):
Step
1. Enter system view.
2. Enter RIB view.
3. Create a RIB IPv6 address family and enter RIB IPv6 address family view.
4. Configure the maximum lifetime for IPv6 routes and labels in the RIB.
Command system-view rib address-family ipv6
protocol protocol lifetime seconds
Remarks
N/A
N/A
By default, no RIB IPv6 address family is created.
By default, the maximum lifetime for routes and labels in the RIB is 480 seconds.
Configuring the maximum lifetime for routes in the
FIB
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.
To configure the maximum lifetime for routes in the FIB (IPv4):
Step
1. Enter system view.
2. Enter RIB view.
Command system-view rib
Remarks
N/A
N/A
4
Step
3. Create a RIB IPv4 address family and enter its view.
Command address-family ipv4
4. Configure the maximum lifetime for IPv4 routes in the
FIB.
fib lifetime seconds
To configure the maximum lifetime for routes in the FIB (IPv6):
Step
1. Enter system view.
2. Enter RIB view.
3. Create a RIB IPv6 address family and enter its view.
4. Configure the maximum lifetime for IPv6 routes in the
FIB.
Command system-view rib address-family ipv6
fib lifetime seconds
Remarks
By default, no RIB IPv4 address family is created.
By default, the maximum lifetime for routes in the FIB is 600 seconds.
Remarks
N/A
N/A
By default, no RIB IPv6 address family is created.
By default, the maximum lifetime for routes in the FIB is 600 seconds.
Configuring the maximum number of ECMP routes
This configuration takes effect at reboot. Make sure the reboot does not impact your network.
To set the maximum number of ECMP routes:
Step
1. Enter system view.
2. Set the maximum number of
ECMP routes.
Command system-view max-ecmp-num number
Remarks
N/A
By default, the maximum number of ECMP routes is 8.
Enabling the 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.
This configuration takes effect at reboot. Make sure the reboot does not impact your network.
To enable the enhanced ECMP mode:
Step
1. Enter system view.
2. Enable the enhanced ECMP mode.
Command system-view ecmp mode enhanced
Remarks
N/A
By default, the enhanced
ECMP mode is disabled.
5
Enabling support for IPv6 routes with prefixes longer than 64 bits
This feature enables a device to support IPv6 routes with prefixes longer than 64 bits.
•
Before configuration, the RIB supports a maximum of 32768 IPv4 routes or 16384 IPv6 routes with prefixes no longer than 64 bits.
•
After configuration, the RIB supports a maximum of 16384 IPv4 routes or 8192 IPv6 routes with prefixes no longer than 64 bits. The remaining RIB space stores a maximum of 4096 IPv6 routes with prefixes longer than 64 bits.
This configuration takes effect at next reboot. Make sure the reboot does not impact your network.
To enable support for IPv6 routes with prefixes longer than 64 bits:
Step
1. Enter system view.
2. Enable support for IPv6 routes with prefixes longer than 64 bits.
Command system-view switch-routing-mode ipv6-128
Remarks
N/A
By default, the device does not support IPv6 routes with prefixes longer than 64 bits.
Displaying and maintaining a routing table
Execute display commands in any view and reset commands in user view.
Task
Display the ECMP mode.
Display routing table information.
Display information about routes permitted by an IPv4 basic ACL.
Display information about routes to a specific destination address.
Display information about routes to a range of destination addresses.
Display information about routes permitted by an IP prefix list.
Display information about routes installed by a protocol.
Display IPv4 route statistics.
Command display ecmp mode display ip routing-table [ vpn-instance vpn-instance-name ]
[ verbose ] [ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] acl acl-number [ verbose ] [ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] ip-address [ mask | mask-length ] [ longer-match ] [ verbose ]
[ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] ip-address1 to ip-address2 [ verbose ] [ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ] [ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] protocol protocol [ inactive | verbose ] [ standby slot slot-number ] display ip routing-table [ vpn-instance vpn-instance-name ] statistics [ standby slot slot-number ]
Display the maximum number of
ECMP routes.
Display route attribute information in the RIB.
Display RIB GR state information. display max-ecmp-num display rib attribute [ attribute-id ] [ standby slot slot-number ] display rib graceful-restart
6
Task
Display next hop information in the
RIB.
Command display rib nib [ self-originated ] [ nib-id ] [ verbose ] [ standby slot slot-number ] display rib nib protocol protocol-name [ verbose ] [ standby slot slot-number ]
Display next hop information for direct routes. display route-direct nib [ nib-id ] [ verbose ]
Clear IPv4 route statistics. reset ip routing-table statistics protocol [ vpn-instance vpn-instance-name ] { protocol | all } [ standby slot slot-number ]
Display IPv6 routing table information. display ipv6 routing-table [ vpn-instance vpn-instance-name ]
[ verbose ] [ standby slot slot-number ]
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 ]
[ standby slot slot-number ]
Display information about routes permitted by an IPv6 basic ACL.
Display information about routes to a range of IPv6 destination addresses. display ipv6 routing-table acl acl6-number [ verbose
[ vpn-instance
] [ standby slot vpn-instance-name slot-number ]
] display ipv6 routing-table [ vpn-instance vpn-instance-name ]
ipv6-address1 to ipv6-address2 [ verbose ] [ standby slot slot-number ]
Display information about routes permitted by an IPv6 prefix list.
Display information about routes installed by an IPv6 protocol.
Display IPv6 route statistics.
Display route attribute information in the IPv6 RIB.
Display IPv6 RIB GR state information. display ipv6 routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ] [ standby slot slot-number ] display ipv6 routing-table [ vpn-instance vpn-instance-name ]
protocol protocol [ inactive | verbose ] [ standby slot slot-number ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] statistics [ standby slot slot-number ] display ipv6 rib attribute [ attribute-id ] [ standby slot slot-number ] display ipv6 rib graceful-restart
Display next hop information in the
IPv6 RIB. display ipv6 rib nib [ self-originated ] [ nib-id ] [ verbose ]
[ standby slot slot-number ] display ipv6 rib nib protocol protocol-name [ verbose ] [ standby slot slot-number ]
Display next hop information for IPv6 direct routes. display ipv6 route-direct nib [ nib-id ] [ verbose ]
Clear IPv6 route statistics. reset ipv6 routing-table statistics protocol [ vpn-instance vpn-instance-name ] { protocol | all } [ standby slot slot-number ]
7
Configuring static routing
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
Before you configure a static route, complete the following tasks:
•
Configure the physical parameters for related interfaces.
•
Configure the link-layer attributes for related interfaces.
•
Configure the IP addresses for related interfaces.
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 .
To configure a static route:
Step Command
1. Enter system view. system-view
2. Configure a static route.
•
Method 1: ip route-static dest-address { mask-length | mask } { interface-type interface-number
[ next-hop-address ] | next-hop-address
[ track track-entry-number ] | vpn-instance d-vpn-instance-name next-hop-address
[ track track-entry-number ] } [ permanent ]
[ preference preference-value ] [ tag tag-value ] [ description description-text ]
•
Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } { interface-type interface-number [ next-hop-address ] | next-hop-address [ public ] [ track track-entry-number ] | vpn-instance d-vpn-instance-name next-hop-address
[ track track-entry-number ] } [ permanent ]
[ preference preference-value ] [ tag tag-value ] [ description description-text ]
3. (Optional.)
Configure the default preference for static routes.
4. (Optional.) Delete all static routes, including the default route. ip route-static default-preference
default-preference-value delete [ vpn-instance vpn-instance-name ] static-routes all
Remarks
N/A
By default, no static route is configured.
The default setting is 60.
To delete one static route, use the undo ip route-static command.
8
Configuring BFD for static routes
IMPORTANT:
Enabling BFD for a flapping route could worsen the situation.
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 .
Bidirectional control mode
To use BFD bidirectional control detection between two devices, enable BFD control mode for each device's static route destined to the peer.
To configure a static route and enable BFD control mode, use one of the following methods:
•
Specify an output interface and a direct next hop.
•
Specify an indirect next hop and a specific BFD packet source address for the static route.
To configure BFD control mode for a static route (direct next hop):
Step Command
1. Enter system view. system-view
2. Configure BFD control mode for a static route.
•
Method 1:
ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd control-packet
[ preference preference-value ] [ tag tag-value ]
[ description description-text ]
•
Method 2: ip route-static vpn-instance
s-vpn-instance-name dest-address
{ mask-length | mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ]
[ tag tag-value ] [ description description-text ]
To configure BFD control mode for a static route (indirect next hop):
Remarks
N/A
By default, BFD control mode for a static route is not configured.
Step Command
1. Enter system view. system-view
Remarks
N/A
9
Step
2. Configure BFD control mode for a static route.
Command
•
Method 1: 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-value ] [ tag tag-value ] [ description description-text ]
•
Method 2: 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-value ] [ tag tag-value ]
[ description description-text ]
Remarks
By default, BFD control mode for a static route is not configured.
Single-hop echo mode
With BFD echo 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.
IMPORTANT:
Do not use BFD for a static route with the output interface in spoofing state.
To configure BFD echo mode for a static route:
Step Command
1. Enter system view. system-view
Remarks
N/A
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 mode for a static route.
•
Method 1: ip route-static dest-address { mask-length | mask } interface-type interface-number
next-hop-address bfd echo-packet
[ preference preference-value ] [ tag tag-value ] [ description description-text ]
•
Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address
{ mask-length | mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ]
[ description description-text ]
By default, BFD echo mode for a static route is not configured.
10
Configuring static route FRR
A link or router failure on a path can cause packet loss and even routing loop. Static route fast reroute
(FRR) uses BFD to detect failures and enables fast rerouting to minimize the impact of link or node failures.
Figure 1 Network diagram
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
As shown in
Figure 1 , upon a link failure, packets are directed to the backup next hop to avoid traffic
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).
Configuration guidelines
•
Do not use static route FRR and BFD (for a static route) at the same time.
•
Static route does not take effect when the backup output interface is unavailable.
•
Equal-cost routes do not support static route FRR.
•
The backup output interface and next hop cannot be modified, and cannot be the same as the primary output interface and next hop.
•
Static route FRR is available only when the state of primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down.
Configuration procedure
Configuring static route FRR by specifying a backup next hop
Step
1. Enter system view.
Command system-view
2. Configure the source address of BFD echo packets. bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of BFD echo packets is not configured.
For more information about this command, see High
Availability Command
Reference .
11
Step
3. Configure static route
FRR.
Command
•
Method 1: 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 ]
•
Method 2: 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 ]
Configuring static route FRR to automatically select a backup next hop
Remarks
By default, static route FRR is not configured.
Step
1. Enter system view.
2. Configure the source address of BFD echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of
BFD echo packets is not configured.
For more information about this command, see High Availability
Command Reference .
3. Configure static route FRR to automatically select a backup next hop. ip route-static fast-reroute auto
By default, static route FRR is disabled.
Enabling BFD echo packet mode for static route FRR
By default, static route FRR does not use BFD 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.
To enable BFD echo packet mode for static route FRR:
Step
1. Enter system view.
Command system-view
2. Configure the source IP address of BFD echo packets.
bfd echo-source-ip ip-address
3. Enable BFD echo packet mode for static route FRR.
ip route-static primary-path-detect bfd echo
Remarks
N/A
By default, the source IP address of BFD echo packets is not configured.
By default, BFD echo mode for static route FRR is disabled.
Displaying and maintaining static routes
Execute display commands in any view.
Task
Display static route information.
Command display ip routing-table protocol static [ inactive | verbose ]
12
Task
Display static route next hop information.
Display static routing table information.
Command display route-static nib [ nib-id ] [ verbose ] display route-static routing-table [ vpn-instance vpn-instance-name ] [ ip-address { mask-length | mask } ]
Static route configuration examples
Basic static route configuration example
Network requirements
As shown in Figure 2 , configure static routes on the switches for interconnections between any two
hosts.
Figure 2 Network diagram
Host B
1.1.6.2/24
Vlan-int100
1.1.6.1/24
Vlan-int500
1.1.4.2/30
Switch B
Vlan-int600
1.1.5.5/30
Vlan-int500
1.1.4.1/30
Vlan-int600
1.1.5.6/30
Host A
1.1.2.2/24
Vlan-int300
1.1.2.3/24
Switch A
Vlan-int900
Switch C
1.1.3.1/24
Host C
1.1.3.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routes:
# Configure a default route on Switch A.
<SwitchA> system-view
[SwitchA] ip route-static 0.0.0.0 0.0.0.0 1.1.4.2
# Configure two static routes on Switch B.
<SwitchB> system-view
[SwitchB] ip route-static 1.1.2.0 255.255.255.0 1.1.4.1
[SwitchB] ip route-static 1.1.3.0 255.255.255.0 1.1.5.6
# Configure a default route on Switch C.
<SwitchC> system-view
[SwitchC] 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 static routes on Switch A.
13
[SwitchA] 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 Vlan500
Static Routing table Status : <Inactive>
Summary Count : 0
# Display static routes on Switch B.
[SwitchB] 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 Vlan500
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),
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
14
Trace complete.
BFD for static routes configuration example (direct next hop)
Network requirements
Configure the following, as shown in
•
Configure a static route to subnet 120.1.1.0/24 on Switch A.
•
Configure a static route to subnet 121.1.1.0/24 on Switch 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
Switch C.
When the link between Switch A and Switch B through the Layer 2 switch fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C.
Figure 3 Network diagram
121.1.1.0/24 120.1.1.0/24
Switch A L2 Switch Switch B
Vlan-int10 Vlan-int10
Vlan-int11 Vlan-int13
BFD
Vlan-int11 Vlan-int13
Switch C
Table 4 Interface and IP address assignment
Device
Switch A
Switch A
Switch B
Switch B
Switch C
Interface
VLAN-interface 10
VLAN-interface 11
VLAN-interface 10
VLAN-interface 13
VLAN-interface 11
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
Switch C VLAN-interface 13 13.1.1.2/24
Configuration procedure
1. Configure IP addresses for the interfaces. (Details not shown.)
2. Configure static routes and BFD:
# Configure static routes on Switch A and enable BFD control mode for the static route that traverses the Layer 2 switch.
<SwitchA> system-view
[SwitchA] interface vlan-interface 10
[SwitchA-vlan-interface10] bfd min-transmit-interval 500
[SwitchA-vlan-interface10] bfd min-receive-interval 500
[SwitchA-vlan-interface10] bfd detect-multiplier 9
[SwitchA-vlan-interface10] quit
15
[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 10 12.1.1.2 bfd control-packet
[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65
[SwitchA] quit
# Configure static routes on Switch B and enable BFD control mode for the static route that traverses the Layer 2 switch.
<SwitchB> system-view
[SwitchB] interface vlan-interface 10
[SwitchB-vlan-interface10] bfd min-transmit-interval 500
[SwitchB-vlan-interface10] bfd min-receive-interval 500
[SwitchB-vlan-interface10] bfd detect-multiplier 9
[SwitchB-vlan-interface10] quit
[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 10 12.1.1.1 bfd control-packet
[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 13 13.1.1.2 preference 65
[SwitchB] quit
# Configure static routes on Switch C.
<SwitchC> system-view
[SwitchC] ip route-static 120.1.1.0 24 13.1.1.1
[SwitchC] ip route-static 121.1.1.0 24 10.1.1.102
Verifying the configuration
# Display BFD sessions on Switch A.
<SwitchA> 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
4/7 12.1.1.1 12.1.1.2 Up 2000ms Vlan10
The output shows that the BFD session has been created.
# Display the static routes on Switch A.
<SwitchA> 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 Vlan10
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails.
# Display static routes on Switch A.
<SwitchA> display ip routing-table protocol static
16
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 Vlan11
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
BFD for static routes configuration example (indirect next hop)
Network requirements
Figure 4 shows the network topology as follows:
•
Switch A has a route to interface Loopback 1 (2.2.2.9/32) on Switch B, with the output interface
VLAN-interface 10.
•
Switch B has a route to interface Loopback 1 (1.1.1.9/32) on Switch A, with the output interface
VLAN-interface 12.
•
Switch D has a route to 1.1.1.9/32, with the output interface VLAN-interface 10, and a route to
2.2.2.9/32, with the output interface VLAN-interface 12.
Configure the following:
•
Configure a static route to subnet 120.1.1.0/24 on Switch A.
•
Configure a static route to subnet 121.1.1.0/24 on Switch 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
Switch C and Switch D.
When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C.
Figure 4 Network diagram
121.1.1.0/24
Loop1
1.1.1.9/32
Loop1
2.2.2.9/32
Switch D
Vlan-int10
Switch A
Vlan
-int
11
Vlan-int10
BFD
Vlan-int12
Vlan-int12
Vlan
-int
13
Switch B
120.1.1.0/24
Vlan-int11 Vlan-int13
Switch C
17
Table 5 Interface and IP address assignment
Device
Switch A
Switch A
Switch A
Switch B
Switch B
Switch B
Switch C
Switch C
Switch D
Interface
VLAN-interface 10
VLAN-interface 11
Loopback 1
VLAN-interface 12
VLAN-interface 13
Loopback 1
VLAN-interface 11
VLAN-interface 13
VLAN-interface 10
IP address
12.1.1.1/24
10.1.1.102/24
1.1.1.9/32
11.1.1.1/24
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
Switch D VLAN-interface 12 11.1.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routes and BFD:
# Configure static routes on Switch A and enable BFD control mode for the static route that traverses Switch D.
<SwitchA> system-view
[SwitchA] bfd multi-hop min-transmit-interval 500
[SwitchA] bfd multi-hop min-receive-interval 500
[SwitchA] bfd multi-hop detect-multiplier 9
[SwitchA] ip route-static 120.1.1.0 24 2.2.2.9 bfd control-packet bfd-source 1.1.1.9
[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65
[SwitchA] quit
# Configure static routes on Switch B and enable BFD control mode for the static route that traverses Switch D.
<SwitchB> system-view
[SwitchB] bfd multi-hop min-transmit-interval 500
[SwitchB] bfd multi-hop min-receive-interval 500
[SwitchB] bfd multi-hop detect-multiplier 9
[SwitchB] ip route-static 121.1.1.0 24 1.1.1.9 bfd control-packet bfd-source 2.2.2.9
[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 13 13.1.1.2 preference 65
[SwitchB] quit
# Configure static routes on Switch C.
<SwitchC> system-view
[SwitchC] ip route-static 120.1.1.0 24 13.1.1.1
[SwitchC] ip route-static 121.1.1.0 24 10.1.1.102
# Configure static routes on Switch D.
<SwitchD> system-view
[SwitchD] ip route-static 120.1.1.0 24 11.1.1.1
[SwitchD] ip route-static 121.1.1.0 24 12.1.1.1
Verifying the configuration
# Display BFD sessions on Switch A.
18
<SwitchA> 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
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 the static routes on Switch A.
<SwitchA> 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 Vlan10
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails.
# Display static routes on Switch A.
<SwitchA> 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 Vlan11
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
19
Static route FRR configuration example
Network requirements
As shown in Figure 5 , configure static routes on Switch A, Switch B, and Switch C, and configure
static route FRR. When Link A becomes unidirectional, traffic can be switched to Link B immediately.
Figure 5 Network diagram
Switch C
Vlan
-int
100
Vlan
-int
101
Link B
Vlan
-int
100
Link A
Loop0
Switch A
Vlan-int200
Table 6 Interface and IP address assignment
Vlan
-int
101
Vlan-int200
Switch B
Loop0
Device
Switch A
Switch A
Switch A
Switch B
Switch B
Switch B
Switch C
Interface
VLAN-interface 100
VLAN-interface 200
Loopback 0
VLAN-interface 101
VLAN-interface 202
Loopback 0
VLAN-interface 100
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
Switch C VLAN-interface 101 24.24.24.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static route FRR on link A by using one of the following methods:
ï‚¡ (Method 1.) Specify a backup next hop for static route FRR:
# Configure a static route on Switch A, and specify VLAN-interface 100 as the backup output interface and 12.12.12.2 as the backup next hop.
<SwitchA> system-view
[SwitchA] bfd echo-source-ip 2.2.2.2
ï‚¡
[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 200 13.13.13.2 backup-interface vlan-interface 100 backup-nexthop 12.12.12.2
# Configure a static route on Switch B, and specify VLAN-interface 101 as the backup output interface and 24.24.24.2 as the backup next hop.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 3.3.3.3
[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 200 13.13.13.1 backup-interface vlan-interface 101 backup-nexthop 24.24.24.2
(Method 2.) Configure static route FRR to automatically select a backup next hop:
# Configure static routes on Switch A, and enable static route FRR.
<SwitchA> system-view
20
[SwitchA] bfd echo-source-ip 4.4.4.4
[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 200 13.13.13.2
[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 100 12.12.12.2 preference 70
[SwitchA] ip route-static fast-reroute auto
# Configure static routes on Switch B, and enable static route FRR.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 1.1.1.1
[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 200 13.13.13.1
[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 101 24.24.24.2 preference 70
[SwitchB] ip route-static fast-reroute auto
3. Configure static routes on Switch C.
<SwitchC> system-view
[SwitchC] ip route-static 4.4.4.4 32 vlan-interface 101 24.24.24.4
[SwitchC] ip route-static 1.1.1.1 32 vlan-interface 100 12.12.12.1
Verifying the configuration
# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.
[SwitchA] 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
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface100
# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.
[SwitchB] 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: 60
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
21
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface101
22
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.
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 a static route ."
•
Some dynamic routing protocols, such as OSPF, RIP, and IS-IS, 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.
23
Configuring RIP
Overview
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 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 metric range 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 ."
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.
•
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 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.
24
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 configuration task list
Tasks at a glance
•
•
(Optional.) Controlling RIP reception and advertisement on interfaces
•
(Optional.) Configuring a RIP version
(Optional.) Configuring RIP route control :
•
Configuring an additional routing metric
•
Configuring RIPv2 route summarization
•
Disabling host route reception
•
•
Configuring received/redistributed route filtering
•
Configuring a preference for RIP
•
Configuring RIP route redistribution
(Optional.) Tuning and optimizing RIP networks :
•
25
Tasks at a glance
•
Enabling split horizon and poison reverse
•
Configuring the maximum number of ECMP routes
•
Enabling zero field check on incoming RIPv1 messages
•
Enabling source IP address check on incoming RIP updates
•
Configuring RIPv2 message authentication
•
•
Configuring RIP network management
•
Configuring the RIP packet sending rate
•
Setting the maximum length of RIP packets
(Optional.) Configuring RIP GR
(Optional.) Configuring BFD for RIP
(Optional.) Configuring RIP FRR
Configuring basic RIP
Before you configure basic RIP settings, complete the following tasks:
•
Configure the link layer protocol.
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring routers.
Enabling 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.
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.
Enabling RIP on a network
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.
To enable RIP on a network:
Step
1. Enter system view.
2. Enable RIP and enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
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.
26
Enabling RIP on an interface
Step
1. Enter system view.
2. Enable RIP and enter RIP view.
3. Return to system view.
4. Enter interface view.
5. Enable RIP on the interface.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] quit interface interface-type
interface-number rip process-id enable
[ exclude-subip ]
Remarks
N/A
By default, RIP is disabled.
N/A
N/A
By default, RIP is disabled on an interface.
Controlling RIP reception and advertisement on interfaces
Step
1. Enter system view.
2. Enter RIP view.
3. Disable an interface from sending RIP messages.
4. Return to system view.
5. Enter interface view.
6. Enable an interface to receive RIP messages.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A silent-interface { interface-type interface-number | all }
N/A
By default, all RIP-enabled interfaces can send RIP messages.
The disabled interface can still receive RIP messages and respond to unicast requests containing unknown ports.
N/A quit interface interface-type interface-number rip input
7. Enable an interface to send
RIP messages. rip output
N/A
By default, a RIP-enabled interface can receive RIP messages.
By default, a RIP-enabled interface can send RIP messages.
Configuring a RIP version
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.
To configure a RIP version:
27
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
3. Specify a global RIP version. version { 1 | 2 }
4. Return to system view.
5. Enter interface view. quit interface interface-type interface-number
N/A
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.
N/A
N/A
6. Specify a RIP version for the interface. rip version { 1 | 2 [ broadcast | multicast ] }
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.
Configuring RIP route control
Before you configure RIP route control, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring routers.
•
Configure basic RIP.
Configuring an additional routing metric
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.
To configure additional routing metrics:
Step
1. Enter system view.
Remarks
N/A
2. Enter interface view.
3. Specify an inbound additional routing metric.
4. Specify an outbound additional routing metric.
Command system-view interface interface-type interface-number rip metricin [ route-policy route-policy-name ] value rip metricout [ route-policy route-policy-name ] value
N/A
The default setting is 0.
The default setting is 1.
28
Configuring RIPv2 route summarization
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.
Enabling RIPv2 automatic route summarization
Automatic summarization enables 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.
To enable RIPv2 automatic route summarization:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. (Optional.) 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
Perform this task to manually configure a summary route.
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 VLAN-interface 1 to advertise the summary route instead of the more specific routes.
To configure a summary route:
Step
1. Enter system view.
2. Enter RIP view.
3. Disable RIPv2 automatic route summarization.
4. Return to system view.
5. Enter interface view.
6. Configure a summary route.
Command system-view
Remarks
N/A rip [ process-id ] [ vpn-instance vpn-instance-name ]
N/A undo summary
By default, RIPv2 automatic route summarization is enabled.
N/A quit
interface interface-type interface-number
rip summary-address
ip-address { mask-length | mask }
N/A
By default, no summary route is configured.
Disabling host route reception
Perform this task to disable RIPv2 from receiving host routes from the same network to save network resources. This feature does not apply to RIPv1.
To disable RIP from receiving host routes:
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Step
1. Enter system view.
2. Enter RIP view.
3. Disable RIP from receiving host routes.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] undo host-route
Remarks
N/A
N/A
By default, RIP receives host routes.
Advertising a default route
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.
To configure RIP to advertise a default route:
Step
1. Enter system view.
2. Enter RIP view.
3. Enable RIP to advertise a default route.
4. Return to system view.
5. Enter interface view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] default-route { only | originate }
[ cost cost ] quit interface interface-type interface-number
Remarks
N/A
N/A
By default, RIP does not advertise a default route.
N/A
N/A
6. Configure the RIP interface to advertise a default route. rip default-route { { only |
originate } [ cost cost ] | no-originate }
By default, a RIP interface can advertise a default route if the RIP process is enabled to advertise a default route.
NOTE:
The router enabled to advertise a default route does not accept default routes from RIP neighbors.
Configuring received/redistributed route filtering
Perform this task to filter received and redistributed routes by using a filtering policy.
To configure route filtering:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
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Step
3. Configure the filtering of received routes.
4. Configure the filtering of redistributed routes.
Command filter-policy { acl-number | gateway prefix-list-name | prefix-list prefix-list-name [ gateway prefix-list-name ] } import
[ interface-type interface-number ] filter-policy { acl-number | prefix-list prefix-list-name } export [ protocol
[ process-id ] | interface-type interface-number ]
Remarks
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.
By default, the filtering of redistributed routes is not configured.
This command filters redistributed routes, including routes redistributed with the import-route command.
Configuring a preference for RIP
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.
To configure a preference for RIP:
Step
1. Enter system view.
2. Enter RIP view.
3. Configure a preference for
RIP.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] preference [ route-policy route-policy-name ] value
Remarks
N/A
N/A
The default setting is 100.
Configuring RIP route redistribution
Perform this task to configure RIP to redistribute routes from other routing protocols, including OSPF,
IS-IS, BGP, static, and direct.
To configure RIP route redistribution:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Redistribute routes from another routing protocol.
import-route protocol
[ process-id | all-processes | allow-ibgp ] [ cost cost |
route-policy route-policy-name |
tag tag ] *
By default, RIP route redistribution is disabled.
This command can redistribute only active routes. To view active routes, use the display ip routing-table protocol command.
4. (Optional.) Configure a default cost for redistributed routes.
default cost value The default setting is 0.
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Tuning and optimizing RIP networks
Configuration prerequisites
Before you tune and optimize RIP networks, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Configure basic RIP.
Configuring RIP timers
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.
IMPORTANT:
To avoid unnecessary traffic or route flapping, configure identical RIP timer settings on RIP routers.
To set RIP timers:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Set RIP timers. timers { garbage-collect garbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value } *
By default:
•
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
The split horizon and poison reverse functions can prevent routing loops.
If both split horizon and poison reverse are configured, only the poison reverse function takes effect.
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Enabling split horizon
Split horizon disables RIP from sending routes through the interface where the routes were learned to prevent routing loops between adjacent routers.
To enable split horizon:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter interface view. interface interface-type interface-number
N/A
3. Enable split horizon. rip split-horizon
By default, split horizon is enabled.
Enabling poison reverse
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.
To enable poison reverse:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Enable poison reverse. rip poison-reverse
By default, poison reverse is disabled.
Configuring the maximum number of ECMP routes
Perform this task to implement load sharing over ECMP routes.
To configure the maximum number of ECMP routes:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Configure the maximum number of ECMP routes. maximum load-balancing number
By default, the maximum number of RIP ECMP routes equals the maximum number of ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of ECMP routes supported by the system.
For more information about the max-ecmp-num command, see
Layer 3—IP Routing Command
Reference.
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Enabling zero field check on incoming RIPv1 messages
Some fields in the RIPv1 message must be set to zero. These fields are called "zero fields." You can enable zero field check on 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.
To enable zero field check on incoming RIPv1 messages:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Enable zero field check on incoming RIPv1 messages. checkzero The default setting is enabled.
Enabling source IP address check on incoming RIP updates
Perform this task to enable source IP address check on 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.
Upon receiving a message on a PPP interface, RIP checks whether the source address of the message is the IP address of the peer interface. If not, RIP discards the message.
To enable source IP address check on incoming RIP updates:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Enable source IP address check on incoming RIP messages. validate-source-address
By default, this function is enabled.
Configuring RIPv2 message authentication
Perform this task to enable authentication on RIPv2 messages. This feature does not apply to RIPv1 because RIPv1 does not support authentication. Although you can specify an authentication mode for RIPv1 in interface view, the configuration does not take effect.
RIPv2 supports two authentication modes: simple authentication and MD5 authentication.
To configure RIPv2 message authentication:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
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Step
3. Configure RIPv2 authentication.
Command rip authentication-mode { md5 { rfc2082
{ cipher cipher-string | plain plain-string } key-id | rfc2453 { cipher cipher-string | plain
plain-string } } | simple { cipher cipher-string |
plain plain-string } }
Remarks
By default, RIPv2 authentication is not configured.
Specifying a RIP neighbor
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 RIP neighbors.
Follow these guidelines when you specify a RIP neighbor:
•
Do not use the peer ip-address command when the neighbor is directly connected. Otherwise, the neighbor might receive both unicast and multicast (or broadcast) messages of the same routing information.
•
If the specified neighbor is not directly connected, disable source address check on incoming updates.
To specify a RIP neighbor:
Step
1. Enter system view.
2. Enter RIP view.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Specify a RIP neighbor. peer ip-address
4. Disable source IP address check on inbound RIP updates undo validate-source-address
By default, RIP does not unicast updates to any peer.
By default, source IP address check on inbound
RIP updates is enabled.
Configuring RIP network management
You can use network management software to manage the RIP process to which MIB is bound.
To configure RIP network management:
Step Command
1. Enter system view. system-view
2. Bind MIB to a RIP process.
rip mib-binding process-id
Remarks
N/A
By default, MIB is bound to the
RIP process with the smallest process ID.
Configuring the RIP packet sending rate
Perform this task to specify 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.
To configure the RIP packet sending rate:
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Step
1. Enter system view.
Command system-view
2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the interval for sending RIP packets and the maximum number of RIP packets that can be sent at each interval.
output-delay time count count
Remarks
N/A
N/A
By default, an interface sends up to three RIP packets every 20 milliseconds.
Setting the maximum length of RIP packets
NOTE:
The supported maximum length of RIP packets varies by vendor. Use this feature with caution to avoid compatibility issues.
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.
To set the maximum length of RIP packets:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Set the maximum length of
RIP packets. rip max-packet-length value
By default, the maximum length of
RIP packets is 512 bytes.
Configuring RIP 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.
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
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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.
To configure GR on the GR restarter:
Step
1. Enter system view.
2. Enter RIP view.
3. Enable GR for RIP.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ] graceful-restart
Remarks
N/A
N/A
By default, RIP GR is disabled.
Configuring 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 direct 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 —In this mode, a BFD session is established to the specified RIP neighbor when RIP is enabled on the local interface.
•
Bidirectional control detection —Detection mode for an indirect neighbor. In this mode, a
BFD session is established only when both ends have routes to send and BFD is enabled on the receiving interface.
Configuring single-hop echo detection (for a directly connected RIP neighbor)
Step
1. Enter system view.
2. Configure the source IP address of BFD echo packets.
3. Enter interface view.
Command system-view
bfd echo-source-ip ip-address interface interface-type interface-number rip bfd enable
Remarks
N/A
By default, the source IP address of BFD echo packets is not configured.
N/A
By default, BFD for RIP is disabled.
4. Enable BFD for RIP.
Configuring single-hop echo detection (for a specific destination)
When a unidirectional link occurs between the local device and a specific neighbor, BFD can detect the failure. The local device will not receive or send any RIP packets through the interface connected to the neighbor to improve convergence speed. When the link recovers, the interface can send RIP packets again.
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This feature applies to RIP neighbors that are directly connected.
To configure BFD for RIP (single hop echo detection for a specific destination):
Step
1. Enter system view.
2. Configure the source IP address of BFD echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, no source IP address is configured for BFD echo packets.
3. Enter interface view.
4. Enable BFD for RIP. interface interface-type interface-number rip bfd enable destination
ip-address
N/A
By default, BFD for RIP is disabled.
Configuring bidirectional control detection
Step
1. Enter system view.
2. Enter RIP view.
3. Specify a RIP neighbor.
Command system-view rip [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
peer ip-address interface interface-type interface-number rip bfd enable
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.
N/A
By default, BFD is disabled on a
RIP interface.
4. Enter interface view.
5. Enable BFD on the RIP interface.
Configuring 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 uses BFD to detect failures and enables fast rerouting to minimize the impact of link or node failures.
Figure 6 Network diagram for RIP FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
As shown in Figure 6 , 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
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calculates the shortest path based on the new network topology, and forwards packets over that path after network convergence.
Configuration restrictions and guidelines
•
RIP FRR takes effect only for RIP routes learned from directly connected neighbors.
•
Do not use RIP FRR and BFD for RIP at the same time. Otherwise, FRR might fail to work.
•
RIP FRR is available only when the state of primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down.
Configuration prerequisites
You must specify a next hop by using the apply fast-reroute backup-interface command in a routing policy and reference the routing policy for FRR. For more information about routing policy
configuration, see " Configuring routing policies ."
Configuration procedure
Configuring RIP FRR
Step
1. Enter system view.
2. Configure the source address of echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of echo packets is not configured.
3. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ]
N/A
4. Configure RIP FRR. fast-reroute route-policy route-policy-name
By default, RIP FRR is disabled.
Enabling BFD for RIP FRR
By default, RIP FRR does not use BFD to detect primary link failures. To speed up RIP convergence, enable BFD single-hop echo detection for RIP FRR to detect primary link failures.
To configure BFD for RIP FRR:
Step
1. Enter system view.
2. Configure the source IP address of BFD echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source IP address of BFD echo packets is not configured.
3. Enter interface view.
4. Enable BFD for RIP FRR. interface interface-type interface-number rip primary-path-detect bfd echo
N/A
By default, BFD for RIP FRR is disabled.
Displaying and maintaining RIP
Execute display commands in any view and execute reset commands in user view.
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Task
Display RIP current status and configuration information.
Display active routes in RIP database.
Display RIP interface information.
Display routing information about a specified RIP process.
Reset a RIP process.
Clear the statistics for a RIP process.
Command display rip [ process-id ]
display rip process-id database [ ip-address
{ mask-length | mask } ]
display rip process-id interface [ interface-type interface-number ]
display rip process-id route [ ip-address
{ mask-length | mask } [ verbose ] | peer ip-address | statistics ]
reset rip process-id process
reset rip process-id statistics
RIP configuration examples
Basic RIP configuration example
Network requirements
As shown in Figure 7 , enable RIPv2 on all interfaces on Switch A and Switch B. Configure Switch B
to not advertise route 10.2.1.0/24 to Switch A, and to accept only route 2.1.1.0/24 from Switch A.
Figure 7 Network diagram
Vlan-int101
3.1.1.1/24
Vlan-int102
2.1.1.1/24
Switch A
Vlan-int100
1.1.1.1/24
Vlan-int101
10.2.1.1/24
Vlan-int100
1.1.1.2/24
Switch B
Vlan-int102
10.1.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP:
# Enable RIP on the specified networks on Switch A.
<SwitchA> system-view
[SwitchA] rip
[SwitchA-rip-1] network 1.0.0.0
[SwitchA-rip-1] network 2.0.0.0
[SwitchA-rip-1] network 3.0.0.0
[SwitchA-rip-1] quit
# Enable RIP on the specified interfaces on Switch B.
<SwitchB> system-view
[SwitchB] rip
[SwitchB-rip-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] rip 1 enable
[SwitchB-Vlan-interface100] quit
[SwitchB] interface vlan-interface 101
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[SwitchB-Vlan-interface101] rip 1 enable
[SwitchB-Vlan-interface101] quit
[SwitchB] interface vlan-interface 102
[SwitchB-Vlan-interface102] rip 1 enable
[SwitchB-Vlan-interface102] quit
# Display the RIP routing table of Switch A.
[SwitchA] display rip 1 route
Route Flags: R - RIP
A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on Vlan-interface100
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 1.1.1.2 1 0 RAOF 11
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 a natural mask.
3. Configure a RIP version:
# Configure RIPv2 on Switch A.
[SwitchA] rip
[SwitchA-rip-1] version 2
[SwitchA-rip-1] undo summary
[SwitchA-rip-1] quit
# Configure RIPv2 on Switch B.
[SwitchB] rip
[SwitchB-rip-1] version 2
[SwitchB-rip-1] undo summary
[SwitchB-rip-1] quit
# Display the RIP routing table on Switch A.
[SwitchA] display rip 1 route
Route Flags: R - RIP
A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on Vlan-interface100
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 1.1.1.2 1 0 RAOF 50
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.
41
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 Switch B.
Route Flags: R - RIP
A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.1 on Vlan-interface100
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 route filtering:
# Reference IP prefix lists on Switch B to filter received and redistributed routes.
[SwitchB] ip prefix-list aaa index 10 permit 2.1.1.0 24
[SwitchB] ip prefix-list bbb index 10 permit 10.1.1.0 24
[SwitchB] rip 1
[SwitchB-rip-1] filter-policy prefix-list aaa import
[SwitchB-rip-1] filter-policy prefix-list bbb export
[SwitchB-rip-1] quit
# Display the RIP routing table on Switch A.
[SwitchA] display rip 100 route
Route Flags: R - RIP
A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.2 on Vlan-interface100
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 Switch B.
[SwitchB] display rip 1 route
Route Flags: R - RIP
A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------------------
Peer 1.1.1.1 on Vlan-interface100
Destination/Mask Nexthop Cost Tag Flags Sec
2.1.1.0/24 1.1.1.1 1 0 RAOF 19
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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 -
RIP route redistribution configuration example
Network requirements
As shown in Figure 8 , Switch B communicates with Switch A through RIP 100 and with Switch C
through RIP 200.
Configure RIP 200 to redistribute direct routes and routes from RIP 100 on Switch B so Switch C can learn routes destined for 10.2.1.0/24 and 11.1.1.0/24. Switch A cannot learn routes destined for
12.3.1.0/24 and 16.4.1.0/24.
Figure 8 Network diagram
RIP 100
Vlan-int101
10.2.1.1/24
Switch A
Vlan-int100
11.1.1.1/24
Eth1/1 Vlan-int100
11.1.1.2/24
Switch B
Vlan-int200
12.3.1.1/24
RIP 200
Vlan-int200
12.3.1.2/24
Switch C
Vlan-int400
16.4.1.1/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP:
# Enable RIP 100, and configure RIPv2 on Switch A.
<SwitchA> system-view
[SwitchA] rip 100
[SwitchA-rip-100] network 10.0.0.0
[SwitchA-rip-100] network 11.0.0.0
[SwitchA-rip-100] version 2
[SwitchA-rip-100] undo summary
[SwitchA-rip-100] quit
# Enable RIP 100 and RIP 200, and configure RIPv2 on Switch B.
<SwitchB> system-view
[SwitchB] rip 100
[SwitchB-rip-100] network 11.0.0.0
[SwitchB-rip-100] version 2
[SwitchB-rip-100] undo summary
[SwitchB-rip-100] quit
[SwitchB] rip 200
[SwitchB-rip-200] network 12.0.0.0
[SwitchB-rip-200] version 2
[SwitchB-rip-200] undo summary
[SwitchB-rip-200] quit
# Enable RIP 200, and configure RIPv2 on Switch C.
<SwitchC> system-view
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[SwitchC] rip 200
[SwitchC-rip-200] network 12.0.0.0
[SwitchC-rip-200] network 16.0.0.0
[SwitchC-rip-200] version 2
[SwitchC-rip-200] undo summary
[SwitchC-rip-200] quit
# Display the IP routing table on Switch C.
[SwitchC] 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
12.3.1.0/24 Direct 0 0 12.3.1.2 Vlan200
12.3.1.0/32 Direct 0 0 12.3.1.2 Vlan200
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 Vlan200
16.4.1.0/24 Direct 0 0 16.4.1.1 Vlan400
16.4.1.0/32 Direct 0 0 16.4.1.1 Vlan400
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 Vlan400
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
3. Configure route redistribution:
# Configure RIP 200 to redistribute routes from RIP 100 and direct routes on Switch B.
[SwitchB] rip 200
[SwitchB-rip-200] import-route rip 100
[SwitchB-rip-200] import-route direct
[SwitchB-rip-200] quit
# Display the IP routing table on Switch C.
[SwitchC] 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 Vlan200
11.1.1.0/24 RIP 100 1 12.3.1.1 Vlan200
12.3.1.0/24 Direct 0 0 12.3.1.2 Vlan200
12.3.1.0/32 Direct 0 0 12.3.1.2 Vlan200
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 Vlan200
16.4.1.0/24 Direct 0 0 16.4.1.1 Vlan400
16.4.1.0/32 Direct 0 0 16.4.1.1 Vlan400
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 Vlan400
44
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
RIP interface additional metric configuration example
Network requirements
Switch E.
Switch A has two links to Switch D. The link from Switch B to Switch D is more stable than that from
Switch C to Switch D. Configure an additional metric for RIP routes received from VLAN-interface
200 on Switch A so Switch A prefers route 1.1.5.0/24 learned from Switch B.
Figure 9 Network diagram
Switch A
Vlan-int100
1.1.1.1/24
Vlan-int100
1.1.1.2/24
Vlan-int200
1.1.2.1/24
Vlan-int200
1.1.2.2/24
Switch B
Vlan-int400
1.1.3.1/24
Vlan-int300
1.1.4.2/24
Vlan-int400
1.1.3.2/24
Vlan-int500
Switch D
1.1.5.1/24
Vlan-int500
1.1.5.2/24
Vlan-int300
1.1.4.1/24
Switch C
Switch E
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] rip 1
[SwitchA-rip-1] network 1.0.0.0
[SwitchA-rip-1] version 2
[SwitchA-rip-1] undo summary
[SwitchA-rip-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] rip 1
[SwitchB-rip-1] network 1.0.0.0
[SwitchB-rip-1] version 2
[SwitchB-rip-1] undo summary
# Configure Switch C.
<SwitchC> system-view
[SwitchB] rip 1
[SwitchC-rip-1] network 1.0.0.0
[SwitchC-rip-1] version 2
[SwitchC-rip-1] undo summary
# Configure Switch D.
45
<SwitchD> system-view
[SwitchD] rip 1
[SwitchD-rip-1] network 1.0.0.0
[SwitchD-rip-1] version 2
[SwitchD-rip-1] undo summary
# Configure Switch E.
<SwitchE> system-view
[SwitchE] rip 1
[SwitchE-rip-1] network 1.0.0.0
[SwitchE-rip-1] version 2
[SwitchE-rip-1] undo summary
# Display all active routes in the RIP database on Switch A.
[SwitchA] 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 Switch B (1.1.1.2) and Switch 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 VLAN-interface 200 on
Switch A.
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] rip metricin 3
# Display all active routes in the RIP database on Switch A.
[SwitchA-Vlan-interface200] 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
Switch B (1.1.1.2) and a cost of 2.
RIP summary route advertisement configuration example
Network requirements
As shown in Figure 10 , Switch A and Switch B run OSPF, Switch D runs RIP, and Switch C runs
OSPF and RIP.
•
Configure RIP to redistribute OSPF routes on Switch C so Switch 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 Switch D, configure route summarization on Switch C to advertise only the summary route 10.0.0.0/8 to Switch D.
46
Figure 10 Network diagram
Vlan-int200
10.1.1.1/24
Vlan-int500
10.6.1.2/24
Vlan-int300
11.3.1.1/24
Vlan-int200
10.1.1.2/24
Switch C
Vlan-int100
10.2.1.2/24
Vlan-int100
10.2.1.1/24
Switch B
Switch A
Vlan-int600
10.5.1.2/24
OSPF
RIP
Vlan-int400
11.4.1.2/24
Switch D
Vlan-int300
11.3.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ospf
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 10.5.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] network 10.6.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
3. Configure basic RIP:
# Configure Switch C.
[SwitchC] rip 1
[SwitchC-rip-1] network 11.3.1.0
[SwitchC-rip-1] version 2
[SwitchC-rip-1] undo summary
# Configure Switch D.
<SwitchD> system-view
[SwitchD] rip 1
47
[SwitchD-rip-1] network 11.0.0.0
[SwitchD-rip-1] version 2
[SwitchD-rip-1] undo summary
[SwitchD-rip-1] quit
# Configure RIP to redistribute routes from OSPF process 1 and direct routes on Switch C.
[SwitchC-rip-1] import-route direct
[SwitchC-rip-1] import-route ospf 1
[SwitchC-rip-1] quit
# Display the IP routing table on Switch D.
[SwitchD] 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 Vlan300
10.2.1.0/24 RIP 100 1 11.3.1.1 Vlan300
10.5.1.0/24 RIP 100 1 11.3.1.1 Vlan300
10.6.1.0/24 RIP 100 1 11.3.1.1 Vlan300
11.3.1.0/24 Direct 0 0 11.3.1.2 Vlan300
11.3.1.0/32 Direct 0 0 11.3.1.2 Vlan300
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 Vlan400
11.4.1.0/32 Direct 0 0 11.4.1.2 Vlan400
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 Switch C and advertise only the summary route 10.0.0.0/8.
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] rip summary-address 10.0.0.0 8
# Display the IP routing table on Switch D.
[SwitchD] 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 Vlan300
11.3.1.0/24 Direct 0 0 11.3.1.2 Vlan300
11.3.1.0/32 Direct 0 0 11.3.1.2 Vlan300
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 Vlan400
11.4.1.0/32 Direct 0 0 11.4.1.2 Vlan400
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
48
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
BFD for RIP configuration example (single-hop echo detection for a directly connected neighbor)
Network requirements
As shown in
Figure 11 , VLAN-interface 100 of Switch A and Switch C runs RIP process 1.
VLAN-interface 200 of Switch A runs RIP process 2. VLAN-interface 300 of Switch C and
VLAN-interface 200 and VLAN-interface 300 of Switch B run RIP process 1.
•
Configure a static route destined for 100.1.1.1/24 and enable static route redistribution into RIP on Switch C. This allows Switch A to learn two routes destined for 100.1.1.1/24 through
VLAN-interface 100 and VLAN-interface 200 respectively, and uses the one through
VLAN-interface 100.
•
Enable BFD for RIP on VLAN-interface 100 of Switch A. When the link over VLAN-interface 100 fails, BFD can quickly detect the failure and notify it to RIP. RIP deletes the neighbor relationship and route information learned on VLAN-interface 100. It uses the route destined for
100.1.1.1 24 through VLAN-interface 200.
Figure 11 Network diagram
Switch B
Vlan-int200
192.168.2.2/24
Vlan-int300
192.168.3.1/24
Vlan-int200
192.168.2.1/24
L2 switch
Vlan-int300
192.168.3.2/24
Switch A
Vlan-int100
192.168.1.1/24
Vlan-int100
192.168.1.2/24
Switch C
BFD
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] rip 1
[SwitchA-rip-1] version 2
[SwitchA-rip-1] undo summary
[SwitchA-rip-1] network 192.168.1.0
[SwitchA-rip-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] rip bfd enable
[SwitchA-Vlan-interface100] quit
[SwitchA] rip 2
49
[SwitchA-rip-2] version 2
[SwitchA-rip-2] undo summary
[SwitchA-rip-2] network 192.168.2.0
[SwitchA-rip-2] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] rip 1
[SwitchB-rip-1] version 2
[SwitchB-rip-1] undo summary
[SwitchB-rip-1] network 192.168.2.0
[SwitchB-rip-1] network 192.168.3.0
[SwitchB-rip-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] rip 1
[SwitchC-rip-1] version 2
[SwitchC-rip-1] undo summary
[SwitchC-rip-1] network 192.168.1.0
[SwitchC-rip-1] network 192.168.3.0
[SwitchC-rip-1] import-route static
[SwitchC-rip-1] quit
3. Configure BFD parameters on VLAN-interface 100 of Switch A.
[SwitchA] bfd echo-source-ip 11.11.11.11
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] bfd min-transmit-interval 500
[SwitchA-Vlan-interface100] bfd min-receive-interval 500
[SwitchA-Vlan-interface100] bfd detect-multiplier 7
[SwitchA-Vlan-interface100] quit
[SwitchA] quit
4. Configure a static route on Switch C.
[SwitchC] ip route-static 120.1.1.1 24 null 0
Verifying the configuration
# Display the BFD session information on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 Session Working Under Echo Mode:
LD SourceAddr DestAddr State Holdtime Interface
4 192.168.1.1 192.168.1.2 Up 2000ms Vlan100
# Display RIP routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 24 verbose
Summary Count : 1
Destination: 120.1.1.0/24
50
Protocol: RIP Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.1.2
Flags: 0x1008c OrigNextHop: 192.168.1.2
Label: NULL RealNextHop: 192.168.1.2
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface100
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch C through VLAN-interface 100. Then the link over VLAN-interface 100 fails.
# Display RIP routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 24 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: RIP Process ID: 2
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NibID: 0x26000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.2.2
Flags: 0x1008c OrigNextHop: 192.168.2.2
Label: NULL RealNextHop: 192.168.2.2
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch C through VLAN-interface 200.
BFD for RIP configuration example (single hop echo detection for a specific destination)
Network requirements
As shown in Figure 12 , VLAN-interface 100 of Switch A and Switch B runs RIP process 1.
VLAN-interface 200 of Switch B and Switch 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 Switch A and Switch C. This allows Switch B to learn two routes destined for
100.1.1.0/24 through VLAN-interface 100 and VLAN-interface 200. The route redistributed from
Switch A has a smaller cost than that redistributed from Switch C, so Switch B uses the route through VLAN-interface 200.
51
•
Enable BFD for RIP on VLAN-interface 100 of Switch A, and specify VLAN-interface 100 of
Switch B as the destination. When a unidirectional link occurs between Switch A and Switch B,
BFD can quickly detect the link failure and notify RIP. Switch B then deletes the neighbor relationship and the route information learned on VLAN-interface 100. It does not receive or send any packets from VLAN-interface 100. When the route learned from Switch A ages out,
Switch B uses the route destined for 100.1.1.1 24 through VLAN-interface 200.
Figure 12 Network diagram
Switch B
Vlan-int100
192.168.2.2/24
Vlan-int200
192.168.3.1/24
Vlan-int100
192.168.2.1/24
Vlan-int200
192.168.3.2/24
Switch A Switch C
RIP packets
BFD session
Configuration procedure
Fault
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP and enable BFD on the interfaces:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] rip 1
[SwitchA-rip-1] network 192.168.2.0
[SwitchA-rip-1] import-route static
[SwitchA-rip-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] rip bfd enable destination 192.168.2.2
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] rip 1
[SwitchB-rip-1] network 192.168.2.0
[SwitchB-rip-1] network 192.168.3.0
[SwitchB-rip-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] rip 1
[SwitchC-rip-1] network 192.168.3.0
[SwitchC-rip-1] import-route static cost 3
[SwitchC-rip-1] quit
3. Configure BFD parameters on VLAN-interface 100 of Switch A.
[SwitchA] bfd echo-source-ip 11.11.11.11
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] bfd min-echo-receive-interval 500
52
[SwitchA-Vlan-interface100] return
4. Configure static routes:
# Configure a static route on Switch A.
[SwitchA] ip route-static 100.1.1.0 24 null 0
# Configure a static route on Switch C.
[SwitchA] ip route-static 100.1.1.0 24 null 0
Verifying the configuration
# Display BFD session information on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 session working under Echo mode:
LD SourceAddr DestAddr State Holdtime Interface
3 192.168.2.1 192.168.2.2 Up 2000ms vlan100
# Display routes destined for 100.1.1.0/24 on Switch B.
<SwitchB> 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: 00h02m47s
Cost: 1 Preference: 100
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
Tunnel ID: Invalid Interface: vlan-interface 100
BkTunnel ID: Invalid BkInterface: N/A
# Display routes destined for 100.1.1.0/24 on Switch B when the link between Switch A and
Switch B fails.
<SwitchB> 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
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
53
NibID: 0x12000002 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
Tunnel ID: Invalid Interface: vlan-interface 200
BkTunnel ID: Invalid BkInterface: N/A
BFD for RIP configuration example (bidirectional detection in
BFD control packet mode)
Network requirements
As shown in Figure 13 , VLAN-interface 100 of Switch A and VLAN-interface 200 of Switch C run RIP
process 1.
VLAN-interface 300 of Switch A runs RIP process 2. VLAN-interface 400 of Switch C, and
VLAN-interface 300 and VLAN-interface 400 of Switch D run RIP process 1.
•
Configure a static route destined for 100.1.1.0/24 on Switch A.
•
Configure a static route destined for 101.1.1.0/24 on Switch C.
•
Enable static route redistribution into RIP on Switch A and Switch C. This allows Switch A to learn two routes destined for 100.1.1.0/24 through VLAN-interface 100 and VLAN-interface
300. It uses the route through VLAN-interface 100.
•
Enable BFD on VLAN-interface 100 of Switch A and VLAN-interface 200 of Switch C.
When the link over VLAN-interface 100 fails, BFD can quickly detect the link failure and notify RIP.
RIP deletes the neighbor relationship and the route information received learned on VLAN-interface
100. It uses the route destined for 100.1.1.0/24 through VLAN-interface 300.
Figure 13 Network diagram
Switch D
Vlan-int300 Vlan-int400
101.1.1.0/24
Vlan-int300
Vlan-int400
Vlan-int100
Vlan-int100
Switch B
Vlan-int200
Vlan-int200
Switch A Switch C
BFD
100.1.1.0/24
Table 7 Interface and IP address assignment
Device
Switch A
Switch A
Switch B
Switch B
Interface
VLAN-interface 300
VLAN-interface 100
VLAN-interface 100
VLAN-interface 200
IP address
192.168.3.1/24
192.168.1.1/24
192.168.1.2/24
192.168.2.1/24
54
Device
Switch C
Switch C
Interface
VLAN-interface 200
VLAN-interface 400
IP address
192.168.2.2/24
192.168.4.2/24
Switch D VLAN-interface 300 192.168.3.2/24
Switch D VLAN-interface 400 192.168.4.1/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic RIP and enable static route redistribution into RIP so Switch A and Switch C have routes to send to each other:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] rip 1
[SwitchA-rip-1] version 2
[SwitchA-rip-1] undo summary
[SwitchA-rip-1] network 192.168.1.0
[SwitchA-rip-1] network 101.1.1.0
[SwitchA-rip-1] peer 192.168.2.2
[SwitchA-rip-1] undo validate-source-address
[SwitchA-rip-1] import-route static
[SwitchA-rip-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] rip bfd enable
[SwitchA-Vlan-interface100] quit
[SwitchA] rip 2
[SwitchA-rip-2] version 2
[SwitchA-rip-2] undo summary
[SwitchA-rip-2] network 192.168.3.0
[SwitchA-rip-2] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] rip 1
[SwitchC-rip-1] version 2
[SwitchC-rip-1] undo summary
[SwitchC-rip-1] network 192.168.2.0
[SwitchC-rip-1] network 192.168.4.0
[SwitchC-rip-1] network 100.1.1.0
[SwitchC-rip-1] peer 192.168.1.1
[SwitchC-rip-1] undo validate-source-address
[SwitchC-rip-1] import-route static
[SwitchC-rip-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] rip bfd enable
[SwitchC-Vlan-interface200] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] rip 1
55
[SwitchD-rip-1] version 2
[SwitchD-rip-1] undo summary
[SwitchD-rip-1] network 192.168.3.0
[SwitchD-rip-1] network 192.168.4.0
3. Configure BFD parameters:
# Configure Switch A.
[SwitchA] bfd session init-mode active
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] bfd min-transmit-interval 500
[SwitchA-Vlan-interface100] bfd min-receive-interval 500
[SwitchA-Vlan-interface100] bfd detect-multiplier 7
[SwitchA-Vlan-interface100] quit
# Configure Switch C.
[SwitchC] bfd session init-mode active
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] bfd min-transmit-interval 500
[SwitchC-Vlan-interface200] bfd min-receive-interval 500
[SwitchC-Vlan-interface200] bfd detect-multiplier 7
[SwitchC-Vlan-interface200] quit
4. Configure static routes:
# Configure a static route to Switch C on Switch A.
[SwitchA] ip route-static 192.168.2.0 24 vlan-interface 100 192.168.1.2
[SwitchA] quit
# Configure a static route to Switch A on Switch C.
[SwitchC] ip route-static 192.168.1.0 24 vlan-interface 200 192.168.2.1
Verifying the configuration
# Display the BFD session information on Switch A.
<SwitchA> 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
513/513 192.168.1.1 192.168.2.2 Up 1700ms vlan100
# Display RIP routes destined for 100.1.1.0/24 on Switch A.
<SwitchB> 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: 00h02m47s
Cost: 1 Preference: 100
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
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NibID: 0x12000002 LastAs: 0
AttrID: 0xffffffff Neighbor: 192.168.2.2
Flags: 0x1008c OrigNextHop: 192.168.2.2
Label: NULL RealNextHop: 192.168.1.2
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: vlan-interface 100
BkTunnel ID: Invalid BkInterface: N/A
# Display RIP routes destined for 100.1.1.0/24 on Switch A when the link between Switch B and
Switch C fails.
<SwitchA> display ip routing-table 100.1.1.0 24 verbose
Summary Count : 1
Destination: 100.1.1.0/24
Protocol: RIP Process ID: 2
SubProtID: 0x1 Age: 00h18m40s
Cost: 2 Preference: 100
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
Tunnel ID: Invalid Interface: vlan-interface 300
BkTunnel ID: Invalid BkInterface: N/A
RIP FRR configuration example
Network requirements
As shown in Figure 14 , Switch A, Switch B, and Switch C run RIPv2. Configure RIP FRR so that
when Link A becomes unidirectional, services can be switched to Link B immediately.
Figure 14 Network diagram
Switch C
Vlan
-int
100
Vlan
-int
101
Link B
Vlan
-int
100
Link A
Loop0
Switch A
Vlan-int200
Table 8 Interface and IP address assignment
Vlan
-int
101
Vlan-int200
Switch B
Loop0
Device
Switch A
Interface
VLAN-interface 100
IP address
12.12.12.1/24
57
Device Interface IP address
Switch A
Switch A
Switch B
Switch B
Switch B
Switch C
VLAN-interface 200
Loopback 0
VLAN-interface 101
VLAN-interface 202
Loopback 0
VLAN-interface 100
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
Switch C VLAN-interface 101 24.24.24.2/24
Configuration procedure
1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
2. Configure RIPv2 on the switches to make sure Switch A, Switch B, and Switch C can communicate with each other at Layer 3. (Details not shown.)
3. Configure RIP FRR:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bfd echo-source-ip 2.2.2.2
[SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32
[SwitchA] route-policy frr permit node 10
[SwitchA-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchA-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
100 backup-nexthop 12.12.12.2
[SwitchA-route-policy-frr-10] quit
[SwitchA] rip 1
[SwitchA-rip-1] fast-reroute route-policy frr
[SwitchA-rip-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 3.3.3.3
[SwitchB] ip prefix-list abc index 10 permit 1.1.1.1 32
[SwitchB] route-policy frr permit node 10
[SwitchB-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchB-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
101 backup-nexthop 24.24.24.2
[SwitchB-route-policy-frr-10] quit
[SwitchB] rip 1
[SwitchB-rip-1] fast-reroute route-policy frr
[SwitchB-rip-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.
[SwitchA] display ip routing-table 4.4.4.4 verbose
Summary Count : 1
Destination: 4.4.4.4/32
58
Protocol: RIP Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 100
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface100
# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.
[SwitchB] 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
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface101
59
Configuring OSPF
Overview
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 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:
•
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.
60
•
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
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 15 .
You can configure route summarization on ABRs to reduce the number of LSAs advertised to other areas and minimize the effect of topology changes.
Figure 15 Area-based OSPF network partition
Area 4
Area 1
Area 0
Area 2
Area 3
61
Backbone area and virtual links
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.
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 16 , 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 16 Virtual link application 1
Transit area
Virtual link
Area 0
ABR ABR
Area 2
Area 1
Virtual links can also be used to provide redundant links. If the backbone area cannot maintain internal connectivity because of the failure of a physical link, you can configure a virtual link to
replace the failed physical link, as shown in Figure 17 .
Figure 17 Virtual link application 2
Area 1
Virtual link
R1 R2
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
62
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 18 , 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 18 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
OSPF routers are classified into the following types based on their positions in the AS:
•
Internal router —All interfaces on an internal router belong to one OSPF area.
•
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 —At least one interface of a backbone router must reside in the backbone area. All ABRs and internal routers in Area 0 are backbone routers.
•
ASBR —Exchanges routing information with another AS is an ASBR. An ASBR might not reside on the border of the AS. It can be an internal router or an ABR.
63
Figure 19 OSPF router types
RIP
IS-IS
ASBR
Area 1
Area 4
Backbone router
Internal router
Area 0
ABR
Area 2
Area 3
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 from a router to the destination 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.
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 from the internal router to the destination of the 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.
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.
64
•
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.
•
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 20 , solid lines are Ethernet physical links, and dashed lines represent OSPF
adjacencies. With the DR and BDR, only seven adjacencies are established.
65
Figure 20 DR and BDR in a network
DR BDR
DR other DR other DR other
Physical links Adjacencies
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 is added to the network after DR and BDR election, the router cannot become the DR or BDR immediately because no DR election is performed for it. 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 1765, OSPF Database Overflow
•
RFC 2328, OSPF Version 2
•
RFC 3101, OSPF Not-So-Stubby Area (NSSA) Option
•
RFC 3137, OSPF Stub Router Advertisement
•
RFC 4811, OSPF Out-of-Band LSDB Resynchronization
•
RFC 4812, OSPF Restart Signaling
•
RFC 4813, OSPF Link-Local Signaling
OSPF configuration task list
To run OSPF, you must first enable OSPF on the router. Make a proper configuration plan to avoid incorrect settings that can result in route blocking and routing loops.
To configure OSPF, perform the following tasks:
66
Tasks at a glance
(Optional.) Configuring OSPF areas :
•
•
•
(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
(Optional.) Configuring OSPF route control :
•
Configuring OSPF route summarization
ï‚¡
ï‚¡
Configuring route summarization on an ABR
Configuring route summarization on an ASBR
ï‚¡
Configuring discard routes for summary networks
•
Configuring received OSPF route filtering
•
Configuring Type-3 LSA filtering
•
Configuring an OSPF cost for an interface
•
Configuring the maximum number of ECMP routes
•
•
Configuring OSPF route redistribution
ï‚¡
Redistributing routes from another routing protocol
ï‚¡
Redistributing a default route
ï‚¡
Configuring default parameters for redistributed routes
•
(Optional.) Tuning and optimizing OSPF networks :
•
•
Specifying LSA transmission delay
•
Specifying SPF calculation interval
•
Specifying the LSA arrival interval
•
Specifying the LSA generation interval
•
Disabling interfaces from receiving and sending OSPF packets
•
•
Configuring OSPF authentication
•
Adding the interface MTU into DD packets
•
Configuring a DSCP value for OSPF packets
•
Configuring the maximum number of external LSAs in LSDB
•
Configuring OSPF exit overflow interval
•
Enabling compatibility with RFC 1583
•
Logging neighbor state changes
•
Configuring OSPF network management
•
Configuring the LSU transmit rate
•
•
Configuring prefix suppression
•
Configuring prefix prioritization
•
•
Configuring the number of OSPF logs
67
Tasks at a glance
(Optional.) Configuring OSPF GR
•
•
•
(Optional.) Configuring OSPF NSR
(Optional.) Configuring BFD for OSPF
(Optional.) Configuring OSPF FRR
Enabling OSPF
Enable OSPF before you perform other OSPF configuration tasks.
Configuration prerequisites
Configure the link layer protocol and IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
Configuration guidelines
To enable OSPF on an interface, 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.
You can specify a global router ID, or specify a router ID when you create an OSPF process.
•
If you specify a router ID when you create an OSPF process, any two routers in an AS must have different router IDs. A common practice is to specify the IP address of an interface as the router ID.
•
If you specify no router ID when you create the OSPF process, the global router ID is used. As a best practice, specify a router ID when you create the OSPF process.
OSPF supports multiple processes and VPNs.
•
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.
•
You can configure an OSPF process to run in a specified VPN instance. For more information about VPN, see MPLS Configuration Guide .
Enabling OSPF on a network
Step
1. Enter system view.
Command system-view
Remarks
N/A
68
Step
2. (Optional.) Configure a global router ID.
Command
router id router-id
Remarks
By default, no global router ID is configured.
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. Enable an OSPF process and enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
4. (Optional.) Configure a description for the OSPF process.
description description
5. Create an OSPF area and enter OSPF area view.
area area-id
6. (Optional.) Configure a description for the area.
description description
By default, OSPF is disabled.
By default, no description is configured for the OSPF process.
As a best practice, configure a description for each OSPF process.
By default, no OSPF area is created.
By default, no description is configured for the area.
As a best practice, configure a description for each OSPF area.
7. Specify a network to enable the interface attached to the network to run the OSPF process in the area.
network ip-address wildcard-mask
Enabling OSPF on an interface
By default, no network is specified.
A network can be added to only one area.
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type
interface-number
Remarks
N/A
N/A
3. Enable an OSPF process on the interface.
ospf process-id area area-id [ exclude-subip ]
By default, OSPF is disabled on an interface.
If the specified OSPF process and area do not exist, the command creates the OSPF process and area. Disabling an OSPF process on an interface does not delete the
OSPF process or the area.
Configuring OSPF areas
Before you configure an OSPF area, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable OSPF.
69
Configuring a stub area
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 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.
To configure an OSPF stub area:
Step
1. Enter system view.
2. Enter OSPF view.
3. Enter area view.
4. Configure the area as a stub area.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * area area-id stub
[ default-route-advertise-alwa ys | no-summary ] *
Remarks
N/A
N/A
N/A
By default, no stub area is configured.
5. (Optional.) Specify a cost for the default route advertised to the stub area.
default-cost cost
The default setting is 1.
The default-cost cost command takes effect only on the ABR of a stub area or totally stub area.
Configuring an NSSA area
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.
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.
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. The ABR of a totally NSSA area does not advertise inter-area routes into the area.
To configure an NSSA area:
Step
1. Enter system view.
2. Enter OSPF view.
3. Enter area view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * area area-id
Remarks
N/A
N/A
N/A
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Step
4. Configure the area as an
NSSA area.
Command nssa [ default-route-advertise
[ cost cost | nssa-only |
route-policy route-policy-name |
type type ] * | no-import-route | no-summary | suppress-fa |
[ translate-always | translate-never ] | translator-stability-interval value ] *
Remarks
By default, no area is configured as an NSSA area.
default-cost cost
The default setting is 1.
This command takes effect only on the ABR/ASBR of an NSSA or totally NSSA area.
5. (Optional.) Specify a cost for the default route advertised to the NSSA area.
Configuring a virtual link
Virtual links are configured for connecting backbone area routers that have no direct physical links.
To configure a virtual link:
Step
1. Enter system view.
2. Enter OSPF view.
3. Enter area view.
4. Configure a virtual link.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * area area-id
N/A
N/A vlink-peer router-id [ dead seconds | hello seconds |
{ { hmac-md5 | md5 } key-id
{ cipher cipher-string | plain plain-string } | simple { cipher cipher-string | plain plain-string } }
| retransmit seconds | trans-delay seconds ] *
By default, no virtual link is configured.
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.
Configuring OSPF network types
OSPF classifies networks into the following types based on the link layer protocol:
•
Broadcast — When the link layer protocol is Ethernet or FDDI, OSPF classifies the network type as broadcast by default.
•
NBMA — When the link layer protocol is Frame Relay, ATM, or X.25, OSPF classifies the network type as NBMA by default.
•
P2P — When the link layer protocol is PPP, LAPB, or HDLC, OSPF classifies the network type as P2P by default.
When you change the network type of an interface, follow these guidelines:
•
When an NBMA network becomes fully meshed, change the network type to broadcast to avoid manual configuration of neighbors.
•
If any routers in a broadcast network do not support multicasting, change the network type to
NBMA.
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•
An NBMA network must be fully meshed. OSPF requires that an NBMA network be fully meshed. If a network is partially meshed, change the network type to P2MP.
•
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.
Configuration prerequisites
Before you configure OSPF network types, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable OSPF.
Configuring the broadcast network type for an interface
Step
1. Enter system view.
Command 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
4. (Optional.) Configure a router priority for the interface.
ospf dr-priority priority
Remarks
N/A
N/A
By default, the network type of an interface depends on the link layer protocol.
The default router priority is 1.
Configuring the NBMA network type for an interface
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.
To configure the NBMA network type for an interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Configure the OSPF network type for the interface as NBMA.
4. (Optional.) Configure a router priority for the interface.
5. Return to system view. ospf network-type nbma ospf dr-priority priority
By default, the network type of an interface depends on the link layer protocol.
The default setting is 1.
The router priority configured with this command is for DR election.
N/A
6. Enter OSPF view.
quit ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
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Step Command
7. Specify a neighbor and its router priority. peer ip-address [ dr-priority dr-priority ]
Remarks
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, and 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
Step
1. Enter system view.
2. Enter interface view.
3. Configure the OSPF network type for the interface as P2MP.
Command system-view interface interface-type interface-number ospf network-type p2mp
[ unicast ]
Remarks
N/A
N/A
By default, the network type of an interface depends on the link layer protocol.
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.
N/A 4. Return to system view.
5. Enter OSPF view. quit ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
6. (Optional.) Specify a neighbor and its router priority. peer ip-address [ cost value ]
By default, no neighbor is specified.
This step must be performed if the network type is P2MP unicast, and is optional if the network type is
P2MP.
Configuring the P2P network type for an interface
Step
1. Enter system view.
2. Enter interface view.
3. Configure the OSPF network type for the interface as P2P.
Command system-view interface interface-type interface-number ospf network-type p2p
[ peer-address-check ]
Remarks
N/A
N/A
By default, the network type of an interface depends on the link layer protocol.
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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.
Configuration prerequisites
Before you configure OSPF route control, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable OSPF.
•
Configure filters if routing information filtering is needed.
Configuring OSPF route summarization
Route summarization enables an ABR or ASBR to summarize contiguous networks into a single network and advertise the network to other areas.
Route summarization reduces the routing information exchanged between areas and the size of routing tables, and improves routing performance. 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 summarize the three networks into network 19.1.0.0/16, and advertise the summary network to other areas.
Configuring route summarization on an ABR
After you configure a summary route on an ABR, the ABR generates a summary LSA instead of specific LSAs. The scale of LSDBs on routers in other areas and the influence of topology changes are reduced.
To configure route summarization on an ABR:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * area area-id
Remarks
N/A
N/A
3. Enter OSPF area view. N/A
4. Configure ABR route summarization.
abr-summary ip-address
{ mask-length | mask } [ advertise | not-advertise ] [ cost cost ]
Configuring route summarization on an ASBR
By default, route summarization is not configured on an ABR.
Perform this task to enable an ASBR to summarize external routes within the specified address range into a single route. The ASBR advertises only the summary route 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.
•
Type-5 LSAs translated by the ASBR (also an ABR) from Type-7 LSAs in an NSSA area.
If the ASBR (ABR) is not a translator, it cannot summarize routes in Type-5 LSAs translated from Type-7 LSAs.
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To configure route summarization on an ASBR:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]*
N/A
3. Configure ASBR route summarization. asbr-summary ip-address
{ mask-length | mask } [ cost cost | not-advertise | nssa-only | tag tag ]
*
Configuring discard routes for summary networks
By default, route summarization is not configured on an ASBR.
Discard routes help prevent routing black holes when route summarization is configured on ABRs and ASBRs.
During route summarization, an ABR or ASBR generates a discard route for the summary network.
The destination and output interface of the discard route is the summary network and interface Null
0. When receiving packets destined for a nonexistent network that is a part of the summary network, the ABR or ASBR discards the packets according to the discard route.
For example, Router A summarizes networks 19.1.1.0/24, 19.1.2.0/24, and 19.1.3.0/24 into network
19.1.0.0/16, and advertises the summary network to Router B. When Router B receives a packet destined for 19.1.4.0/24, Router B forwards the packet to Router A according to the summary route.
Because no specific route to 19.1.4.0/24 exists, Router A discards the packet according to the discard route.
To configure discard routes for summary networks:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Configure discard routes for summary networks.
discard-route { external
{ external-preference | suppression } | internal
{ internal-preference | suppression } } *
By default:
•
The ABR or ASBR generates discard routes for summary networks.
•
The preference of discard routes is 255.
Configuring received OSPF route filtering
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 keyword to filter routing information by next hop.
•
Use an ACL or IP prefix list to filter routing information by destination address and at the same time use the gateway keyword to filter routing information by next hop.
•
Use a routing policy to filter routing information.
To configure OSPF to filter routes calculated using received LSAs:
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Step
1. Enter system view.
2. Enter OSPF view.
3. Configure OSPF to filter routes calculated using received LSAs.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A filter-policy { 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 using received
LSAs.
Configuring Type-3 LSA filtering
Perform this task to filter Type-3 LSAs advertised to an area on an ABR.
To configure Type-3 LSA filtering:
Step
1. Enter system view.
2. Enter OSPF view.
3. Enter area view.
4. Configure Type-3 LSA filtering.
Command system-view ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]
*
N/A area area-id filter { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } { export | import }
Remarks
N/A
N/A
By default, the ABR does not filter Type-3 LSAs.
Configuring an OSPF cost for an interface
Configure an OSPF cost for an interface by using either of the following methods:
•
Configure the cost value in interface view.
•
Configure 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 ).
ï‚¡
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.
ï‚¡ 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.
To configure an OSPF cost for an interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Configure an OSPF cost for the interface.
ospf 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.
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To configure a bandwidth reference value:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Configure a bandwidth reference value.
bandwidth-reference value
Remarks
N/A
N/A
The default setting is 100 Mbps.
Configuring the maximum number of ECMP routes
Perform this task to implement load sharing over ECMP routes.
To configure the maximum number of ECMP routes:
Step
1. Enter system view.
2. Enter OSPF view.
3. Configure the maximum number of ECMP routes.
Command system-view ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]
*
N/A maximum load-balancing maximum
Remarks
N/A
By default, the maximum number of OSPF ECMP routes equals the maximum number of ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of ECMP routes supported by the system. For more information about the max-ecmp-num command, see Layer 3—IP
Routing Command Reference.
Configuring OSPF preference
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.
To configure OSPF preference:
Step Command
1. Enter system view. system-view
2. Enter OSPF view.
3. Configure a preference for
OSPF.
Remarks
N/A ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]
*
N/A preference [ ase ] [ route-policy-name ] route-policy value
By default, the preference of OSPF internal routes is 10 and the preference of OSPF external routes is 150.
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Configuring OSPF route redistribution
On a router running OSPF and other routing protocols, you can configure OSPF to redistribute routes from other protocols, such as RIP, IS-IS, BGP, static, and direct, and advertise them 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.
IMPORTANT:
The import-route bgp command redistributes only EBGP routes. Because the import-route bgp allow-ibgp command redistributes both EBGP and IBGP routes, and might cause routing loops, use it with caution.
Redistributing routes from another routing protocol
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Configure OSPF to redistribute routes from another routing protocol. import-route protocol [ process-id |
all-processes | allow-ibgp ]
[ allow-direct | cost cost | nssa-only |
route-policy route-policy-name | tag tag | type type ] *
By default, no route redistribution is configured.
This command redistributes only active routes. To view information about active routes, use the display ip routing-table protocol command.
4. (Optional.) Configure
OSPF to filter redistributed routes.
Redistributing a default route filter-policy { acl-number | prefix-list prefix-list-name } export [ protocol
[ process-id ] ]
By default, OSPF accepts all redistributed routes.
The import-route command cannot redistribute a default external route. Perform this task to redistribute a default route.
To redistribute a default route:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Redistribute a default route. default-route-advertise [ [ [ always | permit-calculate-other ] | cost cost | route-policy route-policy-name | type
type ] * | summary cost cost ]
By default, no default route is redistributed.
This command is applicable only to VPNs. The PE router advertises a default route in a
Type-3 LSA to a CE router.
Configuring default parameters for redistributed routes
Perform this task to configure default parameters for redistributed routes, including cost, tag, and type. Tags indicate information about protocols. For example, when redistributing BGP routes, OSPF uses tags to identify AS IDs.
To configure the default parameters for redistributed routes:
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Step
1. Enter system view.
2. Enter OSPF view.
3. Configure the default parameters for redistributed routes
(cost, upper limit, tag, and type).
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A default { cost cost | tag tag | type type } *
By default, the cost is 1, the tag is 1, and the type is Type-2.
Advertising a host route
Step
1. Enter system view.
2. Enter OSPF view.
3. Enter area view.
4. Advertise a host route.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * area area-id host-advertise ip-address cost
Remarks
N/A
N/A
N/A
By default, no host route is advertised.
Tuning and optimizing OSPF networks
You can use one of the following methods to optimize an OSPF network:
•
Change OSPF packet timers to adjust the convergence speed and network load. On low-speed links, consider the delay time for sending LSAs.
•
Change the SPF calculation interval to reduce resource consumption caused by frequent network changes.
•
Configure OSPF authentication to improve security.
Configuration prerequisites
Before you configure OSPF network optimization, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable OSPF.
Configuring OSPF timers
An OSPF interface includes the following timers:
•
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.
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To configure OSPF timers:
Command Step
1. Enter system view.
2. Enter interface view.
system-view interface interface-type interface-number
Remarks
N/A
3.
4.
5. Specify the dead interval.
6.
Specify the hello interval.
Specify the poll interval.
Specify the retransmission interval. ospf timer hello ospf timer poll ospf timer dead seconds seconds seconds ospf timer retransmit interval
N/A
By default:
•
The hello interval on P2P and broadcast interfaces is 10 seconds.
•
The hello interval on P2MP and NBMA interfaces is 30 seconds.
The default hello interval is restored when the network type for an interface is changed.
The default setting is 120 seconds.
The poll interval is at least four times the hello interval.
By default:
•
The dead interval on P2P and broadcast interfaces is 40 seconds.
•
The dead interval on P2MP and NBMA interfaces is 120 seconds.
The dead interval must be at least four times the hello interval on an interface.
The default dead interval is restored when the network type for an interface is changed.
The default setting is 5 seconds.
A retransmission interval setting that is too small can cause unnecessary LSA retransmissions. This interval is typically set bigger than the round-trip time of a packet between two neighbors.
Specifying LSA transmission delay
To avoid LSAs from aging out during transmission, set an LSA retransmission delay especially for low speed links.
To specify the LSA transmission delay on an interface:
Step
1. Enter system view.
Command system-view
2. Enter interface view.
interface interface-type interface-number
3. Specify the LSA transmission delay.
ospf trans-delay seconds
Remarks
N/A
N/A
The default setting is 1 second.
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Specifying SPF calculation interval
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 is incremented 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.
To configure the SPF calculation interval:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Specify 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.
•
The incremental interval is 200 milliseconds.
Specifying the LSA arrival interval
If OSPF receives an LSA that has the same LSA type, LS ID, and router ID as the previously received
LSA within the LSA arrival interval, OSPF discards the LSA to save bandwidth and route resources.
To configure the LSA arrival interval:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Configure the LSA arrival interval.
lsa-arrival-interval interval
The default setting is 1000 milliseconds.
Make sure this interval is smaller than or equal to the interval set with the lsa-generation-interva l command.
Specifying the LSA generation interval
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 is incremented 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.
To configure the LSA generation interval:
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Step
1. Enter system view.
2. Enter OSPF view.
3. Configure the LSA generation interval.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A lsa-generation-interval maximum-interval [ minimum-interval
[ incremental-interval ] ]
By default:
•
The maximum interval is 5 seconds.
•
The minimum interval is 50 milliseconds.
•
The incremental interval is 200 milliseconds.
Disabling interfaces from receiving and sending OSPF packets
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.
To disable interfaces from receiving and sending routing information:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
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.
The silent-interface 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.
Configuring stub routers
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.
To configure a router as a stub router:
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Step
1. Enter system view.
2. Enter OSPF view.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
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.
Configuring OSPF authentication
Perform this task to configure OSPF area and interface authentication.
OSPF adds the configured password into sent packets, and uses the password 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.
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
You must configure the same authentication mode and password on all the routers in an area.
To configure OSPF area authentication:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
3. Enter area view.
4. Configure area authentication mode. area area-id
•
Configure MD5 authentication: authentication-mode { hmac-md5 | md5 } key-id { cipher | plain } password
•
Configure simple authentication:
authentication-mode simple
{ cipher | plain } password
Configuring OSPF interface authentication
N/A
By default, no authentication is configured.
You must configure the same authentication mode and password on both the local interface and its peer interface.
To configure OSPF interface authentication:
Step
1. Enter system view.
2. Enter interface view.
Command system-view
Remarks
N/A interface interface-type interface-number N/A
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Step
3. Configure interface authentication mode.
Command
•
Configure simple authentication: ospf authentication-mode simple
{ cipher cipher-string | plain plain-string }
•
Configure MD5 authentication: ospf authentication-mode
{ hmac-md5 | md5 } key-id { cipher cipher-string | plain plain-string }
Remarks
By default, no authentication is configured.
Adding the interface MTU into DD packets
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.
To add the interface MTU into DD packets:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
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.
Configuring a DSCP value for OSPF packets
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Configure a DSCP value for
OSPF packets. dscp dscp-value
Remarks
N/A
N/A
By default, the DSCP value for OSPF packets is 48.
Configuring the maximum number of external LSAs in LSDB
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Specify the maximum number of external LSAs in the LSDB.
lsdb-overflow-limit number
Remarks
N/A
N/A
By default, the maximum number of external LSAs in the
LSDB is not limited.
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Configuring OSPF exit overflow interval
When the number of LSAs in the LSDB exceeds the upper limit, the LSDB is in an overflow state. To save resources, OSPF does not receive any external LSAs and deletes the external LSAs generated by itself when in this state.
Perform this task to configure the interval that OSPF exits overflow state.
To configure the OSPF exit overflow interval:
Step
1. Enter system view.
2. Enter OSPF view.
3. Configure the OSPF exit overflow interval.
Command system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
lsdb-overflow-interval interval
The default setting is 300 seconds.
The value of 0 indicates that
OSPF does not exit overflow state.
Enabling compatibility with RFC 1583
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.
ï‚¡
If RFC 2328 is compatible with RFC 1583, all these routes have equal preference.
ï‚¡
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 lower cost if two routes have equal preference.
3. Selects the route with larger originating area ID if two routes have equal cost.
To avoid routing loops, as a best practice, set identical RFC 1583-compatibility on all routers in a routing domain.
To enable compatibility with RFC 1583:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Enable compatibility with RFC 1583.
rfc1583 compatible By default, this feature is enabled.
Logging neighbor state changes
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 Network Management and
Monitoring Configuration Guide .
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To enable the logging of neighbor state changes:
Step
1. Enter system view.
2. Enter OSPF view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable the logging of neighbor state changes. log-peer-change
Remarks
N/A
N/A
By default, this feature is enabled.
Configuring OSPF network management
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 maximum number of output SNMP notifications within a specified time interval.
SNMP notifications are sent to the SNMP module, which outputs SNMP notifications according to the configured output rules. For more information about SNMP notifications, see Network Management and Monitoring Configuration Guide .
To configure OSPF network management:
Step
1. Enter system view.
2. Bind OSPF MIB to an
OSPF process.
Command system-view
ospf mib-binding process-id
Remarks
N/A
By default, OSPF 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 is enabled.
4. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
5. Configure the maximum number of output SNMP notifications within a specified time interval.
snmp trap rate-limit interval trap-interval
count trap-number
By default, OSPF outputs a maximum of seven SNMP notifications within 10 seconds.
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Configuring the LSU transmit rate
Sending large numbers of LSU packets affects router performance and consumes too much network bandwidth. You can configure the router to send LSU packets at a proper interval and limit the maximum number of LSU packets sent out of an OSPF interface each time.
To configure the LSU transmit rate:
Step
2. Enter OSPF view.
3. Configure the LSU transmit rate.
Command
1. Enter system view. system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A transmit-pacing interval interval count count
By default, an OSPF interface sends a maximum of three
LSU packets every 20 milliseconds.
Enabling OSPF ISPF
When the topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT.
To enable OSPF ISPF:
Step Command
1. Enter system view. system-view
2. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Enable OSPF ISPF. ispf enable
By default, OSPF ISPF is enabled.
Configuring prefix suppression
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 function 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 the primary IP addresses of interfaces in Type-1 LSAs.
IMPORTANT:
If you want to use prefix suppression, as a best practice, configure prefix suppression on all OSPF routers.
87
Configuring prefix suppression for an OSPF process
Enabling prefix suppression for an OSPF process does not suppress the prefixes of secondary IP addresses, loopback interfaces, and passive interfaces. To suppress the prefixes of loopback and passive interfaces, enable prefix suppression on the interfaces.
To configure prefix suppression for an OSPF process:
Step Command
1. Enter system view. system-view
Remarks
N/A
2. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable prefix suppression for the
OSPF process. prefix-suppression
Configuring prefix suppression for an interface
N/A
By default, prefix suppression is disabled for an OSPF process.
Interface prefix suppression does not suppress prefixes of secondary IP addresses.
To configure interface prefix suppression:
Step Command
1. Enter system view. system-view
2. Enter interface view.
3. Enable prefix suppression for the interface. interface interface-type interface-number ospf prefix-suppression [ disable ]
Remarks
N/A
N/A
By default, prefix suppression is disabled on an interface.
Configuring prefix prioritization
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 a low priority.
To configure prefix prioritization:
Step
2. Enter OSPF view.
3. Enable prefix prioritization.
Command
1. Enter system view. system-view
Remarks
N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
prefix-priority route-policy route-policy-name
By default, prefix prioritization is disabled.
Configuring OSPF PIC
Prefix Independent Convergence (PIC) enables the device to speed up network convergence by ignoring the number of prefixes.
When both OSPF PIC and OSPF FRR are configured, OSPF FRR takes effect.
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OSPF PIC applies only to inter-area routes and external routes.
Enabling OSPF PIC
Step Command
1. Enter system view. system-view
Remarks
N/A
2. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable PIC for
OSPF.
Configuring BFD for OSPF PIC pic [ additional-path-always ]
N/A
By default, OSPF PIC is enabled.
By default, OSPF PIC does not use BFD to detect primary link failures. To speed up OSPF convergence, enable BFD single-hop echo detection for OSPF PIC to detect the primary link failures.
To configure BFD for OSPF PIC:
Step
1. Enter system view.
2. Configure the source IP address of BFD echo packets.
Command system-view bfd echo-source-ip ip-address
Remarks
N/A
By default, the source IP address of BFD echo packets is not configured.
3. Enter interface view.
4. Enable BFD for OSPF PIC. interface interface-type
interface-number ospf primary-path-detect bfd echo
N/A
By default, BFD for OSPF PIC is disabled.
Configuring the number of OSPF logs
OSPF logs include route calculation logs and neighbor logs.
To configure the number of OSPF logs:
Step
2. Enter OSPF view.
Command
1. Enter system view. system-view
Remarks
N/A ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]
*
N/A
3. Configure the number of OSPF logs. event-log { lsa-flush | peer | spf } size count
By default, the number of both route calculation logs and neighbor logs is 10.
Configuring 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.
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•
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.
Configuring OSPF GR restarter
You can configure the IETF or non-IETF OSPF GR restarter.
IMPORTANT:
You cannot enable OSPF NSR on a device that acts as GR restarter.
Configuring the IETF OSPF GR restarter
Remarks
N/A
Step
1. Enter system view.
Command system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable opaque LSA reception and advertisement capability. opaque-capability enable
4. Enable the IETF GR. graceful-restart ietf [ global | planned-only ] *
5. (Optional.) Configure the GR interval. graceful-restart interval interval-value
Configuring the non-IETF OSPF GR restarter
N/A
By default, opaque LSA reception and advertisement capability is enabled.
By default, the IETF GR capability is disabled.
By default, the GR interval is 120 seconds.
Step
1. Enter system view.
2. Enable OSPF and enter its view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable the link-local signaling capability.
4. Enable the out-of-band re-synchronization capability. enable link-local-signaling enable out-of-band-resynchronization
5. Enable non-IETF GR. graceful-restart [ nonstandard ]
[ global | planned-only ] *
6. (Optional.) Configure the GR interval. graceful-restart interval interval-value
Remarks
N/A
N/A
By default, the link-local signaling capability is disabled.
By default, the out-of-band re-synchronization capability is disabled.
By default, non-IETF GR capability is disabled.
By default, the GR interval is 120 seconds.
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Configuring OSPF GR helper
You can configure the IETF or non-IETF OSPF GR helper.
Configuring the IETF OSPF GR helper
Step
1. Enter system view.
Command system-view
2. Enable OSPF and enter its view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
3. Enable opaque LSA reception and advertisement capability. opaque capability enable
4. (Optional.) Enable GR helper capability. graceful-restart helper enable
[ planned-only ]
5. (Optional.) Enable strict LSA checking for the GR helper. graceful-restart helper strict-lsa-checking
Configuring the non-IETF OSPF GR helper
Remarks
N/A
N/A
By default, opaque LSA reception and advertisement capability is enabled.
By default, GR helper capability is enabled.
By default, strict LSA checking for the GR helper is disabled.
Step
1. Enter system view.
2. Enable OSPF and enter its view.
Command system-view ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Enable the link-local signaling capability. enable link-local-signaling
4. Enable the out-of-band re-synchronization capability. enable out-of-band-resynchronization
By default, the link-local signaling capability is disabled.
By default, the out-of-band re-synchronization capability is disabled.
5. (Optional.) Enable GR helper.
6. (Optional.) Enable strict LSA checking for the GR helper. graceful-restart helper enable graceful-restart helper strict-lsa-checking
By default, GR helper is enabled.
By default, strict LSA checking for the GR helper is disabled.
Triggering OSPF GR
OSPF GR is triggered by an active/standby switchover or when the following command is executed.
To trigger OSPF GR, perform the following command in user view:
Task
Trigger OSPF GR.
Command reset ospf [ process id ] process graceful-restart
91
Configuring OSPF NSR
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 is used more often than GR.
IMPORTANT:
A device that has OSPF NSR enabled cannot act as GR restarter.
To enable OSPF NSR:
Step Command
1. Enter system view. system-view
Remarks
N/A
2. Enter OSPF view. ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ]
*
3. Enable OSPF NSR. non-stop-routing
N/A
By default, OSPF NSR is disabled.
Configuring 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
Step
1. Enter system view.
2. Enter interface view.
3. Enable BFD bidirectional control detection.
Command system-view interface interface-type interface-number ospf bfd enable
Remarks
N/A
N/A
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.
92
Configuring single-hop echo detection
Step
1. Enter system view.
2. Configure the source address of echo packets.
3. Enter interface view.
4. Enable BFD single-hop echo detection.
Command system-view bfd echo-source-ip ip-address interface interface-type interface-number ospf bfd enable echo
Remarks
N/A
By default, the source address of echo packets is not configured.
N/A
By default, BFD single-hop echo detection is disabled.
Configuring OSPF FRR
A link or router failure on a path can cause packet loss and even routing loop until OSPF completes routing convergence based on the new network topology. FRR uses BFD to detect failures and enables fast rerouting to minimize the impact of link or node failures.
Figure 21 Network diagram for OSPF FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
As shown in Figure 21 , configure FRR on Router B by using a routing policy to specify a backup next
hop. 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.
You can configure OSPF 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.
Configuration prerequisites
Before you configure OSPF FRR, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable OSPF.
Configuration guidelines
•
Do not use FRR and BFD at the same time. Otherwise, FRR might fail to take effect.
•
Do not use the fast-reroute lfa command together with the vlink-peer or sham-link (see
MPLS Command Reference ) command.
•
When both OSPF PIC and OSPF FRR are configured, OSPF FRR takes effect.
93
Configuration procedure
Configuring OSPF FRR to calculate a backup next hop using the LFA algorithm
Step
1. Enter system view.
Command system-view
Remarks
N/A
2.
3.
Configure the source address of echo packets.
Enter interface view. bfd echo-source-ip ip-address interface interface-type
interface-number
By default, the source address of echo packets is not configured.
4. Enable LFA calculation on an interface. ospf fast-reroute lfa-backup
By default, the interface on which LFA calculation is enabled can be selected as a backup interface.
5. Return to system view. quit
N/A
N/A
6. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
7. Enable OSPF FRR to calculate a backup next hop by using the LFA algorithm. fast-reroute lfa [ abr-only ]
By default, OSPF FRR is not configured.
If abr-only is specified, the route to the ABR is selected as the backup path.
Configuring OSPF FRR to specify a backup next hop using a routing policy
Before you configure this task, use the apply fast-reroute backup-interface command to specify a backup next hop in the routing policy to be referenced. For more information about the apply fast-reroute backup-interface
command and routing policy configuration, see " Configuring routing policies ."
To configure OSPF FRR to specify a backup next hop using a routing policy:
Step
1. Enter system view.
2. Configure the source address of echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of echo packets is not configured.
3. Enter OSPF view.
ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
N/A
4. Enable OSPF FRR to specify a backup next hop by using a routing policy.
Configuring BFD for OSPF FRR fast-reroute route-policy route-policy-name
By default, OSPF FRR is not configured.
By default, OSPF FRR does not use BFD to detect primary link failures. To speed up OSPF convergence, enable BFD single-hop echo detection for OSPF FRR to detect primary link failures.
To configure BFD for OSPF FRR:
Step Command
1. Enter system view. system-view
Remarks
N/A
94
Step
2. Configure the source IP address of BFD echo packets.
3. Enter interface view.
4. Enable BFD for
OSPF FRR.
Command bfd echo-source-ip ip-address interface interface-type interface-number ospf primary-path-detect bfd echo
Remarks
By default, the source IP address of BFD echo packets is not configured.
N/A
By default, BFD for OSPF
FRR is disabled.
Displaying and maintaining OSPF
Execute display commands in any view and reset commands in user view.
Task
Display OSPF process information.
Display OSPF GR information.
Display OSPF FRR backup next hop information.
Command display ospf [ process-id ] [ verbose ] [ standby slot slot-number ] display ospf [ process-id ] graceful-restart [ verbose ] display ospf [ process-id ] [ area area-id ] fast-reroute lfa-candidate
Display OSPF LSDB information. display ospf [ process-id ] lsdb [ area area-id | brief | [ { asbr | ase | network | nssa | opaque-area | opaque-as | opaque-link | router | summary } [ link-state-id ] ] [ originate-router advertising-router-id | self-originate ] ]
Display OSPF next hop information.
Display OSPF neighbor information.
Display neighbor statistics for
OSPF areas. display ospf display ospf display ospf
[ process-id
[
[ process-id interface-number ] [ process-id
]
]
]
nexthop
peer neighbor-id peer
]
[ verbose statistics
] [ interface-type
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 OSPF statistics. display ospf [ process-id ] statistics [ error | packet [ interface-type interface-number ] ]
Display OSPF virtual link information.
Display OSPF request queue information.
Display OSPF retransmission queue information.
Display OSPF ABR and ASBR information.
Display summary route information on the OSPF ABR. display
{ ospf display ospf display ospf display ospf display ospf
[ mask-length
[
[
[
| process-id
process-id interface-number
[ interface-number
] [ process-id
] [ process-id
process-id
mask } ] [
]
]
]
]
vlink
] [ request-queue neighbor-id neighbor-id
] retrans-queue
] abr-asbr [
[
[ interface-type
interface-type verbose
area area-id verbose ]
]
]
abr-summary [ ip-address
95
Task
Display OSPF interface information.
Display OSPF route calculation log information.
Display OSPF ASBR route summarization information.
Display the global route ID.
Clear OSPF statistics.
Clear OSPF log information.
Reset an OSPF process.
Re-enable OSPF route redistribution.
Command display ospf [ process-id ] interface [ interface-type interface-number | verbose ] display ospf [ process-id ] event-log { lsa-flush | peer | spf } display ospf [ process-id ] asbr-summary [ ip-address { mask-length | mask } ] display router id reset ospf [ process-id ] statistics reset ospf [ process-id ] event-log [ lsa-flush | peer | spf ] reset ospf [ process-id ] process [ graceful-restart ] reset ospf [ process-id ] redistribution
OSPF configuration examples
These configuration examples only cover commands for OSPF configuration.
Basic OSPF configuration example
Network requirements
•
Enable OSPF on all switches, and split the AS into three areas.
•
Configure Switch A and Switch B as ABRs.
Figure 22 Network diagram
Switch A
Vlan-int100
Area 0
10.1.1.1/24
Vlan-int200
10.2.1.1/24
Vlan-int100
10.1.1.2/24
Switch B
Vlan-int200
10.3.1.1/24
Area 2
Vlan-int200
10.3.1.2/24
Area 1
Vlan-int200
10.2.1.2/24
Switch C
Vlan-int300
10.4.1.1/24
Vlan-int300
10.5.1.1/24 Switch D
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] router id 10.2.1.1
[SwitchA] ospf
[SwitchA-ospf-1] area 0
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[SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] area 1
[SwitchA-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.1] quit
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] router id 10.3.1.1
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] area 2
[SwitchB-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.2] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] router id 10.4.1.1
[SwitchC] ospf
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.1] network 10.4.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.1] quit
[SwitchC-ospf-1] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] router id 10.5.1.1
[SwitchD] ospf
[SwitchD-ospf-1] area 2
[SwitchD-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.2] network 10.5.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.2] quit
[SwitchD-ospf-1] quit
Verifying the configuration
# Display information about neighbors on Switch A.
[SwitchA] 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(Vlan-interface100)'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
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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(Vlan-interface200)'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
# Display OSPF routing information on Switch A.
[SwitchA] display ospf routing
OSPF Process 1 with Router ID 10.2.1.1
Routing Tables
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 Switch D.
[SwitchD] display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Tables
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
# On Switch D, ping the IP address 10.4.1.1 to test reachability.
[SwitchD] ping 10.4.1.1
98
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 round-trip min/avg/max/std-dev = 0.779/1.408/1.702/0.323 ms
OSPF route redistribution configuration example
Network requirements
•
Enable OSPF on all the switches.
•
Split the AS into three areas.
•
Configure Switch A and Switch B as ABRs.
•
Configure Switch C as an ASBR to redistribute external routes (static routes).
Figure 23 Network diagram
Area 1
Switch A
Vlan-int100
Area 0
10.1.1.1/24
Vlan-int100
10.1.1.2/24
Vlan-int200
10.2.1.1/24
Switch B
Vlan-int200
10.3.1.1/24
Vlan-int200
10.2.1.2/24
Area 2
Vlan-int200
10.3.1.2/24
Switch C
Vlan-int300
10.4.1.1/24
Vlan-int500
10.5.1.1/24
Switch D
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2.
Enable OSPF (see " Basic OSPF configuration example ").
3. Configure OSPF to redistribute routes:
# On Switch C, configure a static route destined for network 3.1.2.0/24.
<SwitchC> system-view
[SwitchC] ip route-static 3.1.2.1 24 10.4.1.2
# On Switch C, configure OSPF to redistribute static routes.
[SwitchC] ospf 1
[SwitchC-ospf-1] import-route static
Verifying the configuration
# Display the ABR/ASBR information of Switch D.
<SwitchD> display ospf abr-asbr
99
OSPF Process 1 with Router ID 10.5.1.1
Routing Table to ABR and ASBR
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 table on Switch D.
<SwitchD> display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Tables
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
OSPF route summarization configuration example
Network requirements
•
Configure OSPF on Switch A and Switch B in AS 200.
•
Configure OSPF on Switch C, Switch D, and Switch E in AS 100.
•
Configure an EBGP connection between Switch B and Switch C. Configure Switch B and
Switch C to redistribute OSPF routes and direct routes into BGP and BGP routes into OSPF.
•
Configure Switch B to advertise only summary route 10.0.0.0/8 to Switch A.
100
Figure 24 Network diagram
Vlan-int500
10.3.1.1/24
Switch D
Vlan-int400
10.1.1.1/24
Vlan-int300
10.2.1.2/24
Switch E
Vlan-int600
10.4.1.1/24
Vlan-int400
10.1.1.2/24
Vlan-int300
10.2.1.1/24
Switch C
AS 100 Vlan-int200
11.1.1.2/24
EBGP
Vlan-int200
11.1.1.1/24
Switch B
Vlan-int100
11.2.1.2/24
Vlan-int100
11.2.1.1/24
AS 200
Switch A
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] router id 11.2.1.2
[SwitchA] ospf
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 11.2.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] router id 11.2.1.1
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 11.2.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] router id 11.1.1.2
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
# Configure Switch D.
101
<SwitchD> system-view
[SwitchD] router id 10.3.1.1
[SwitchD] ospf
[SwitchD-ospf-1] area 0
[SwitchD-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] network 10.3.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] quit
# Configure Switch E.
<SwitchE> system-view
[SwitchE] router id 10.4.1.1
[SwitchE] ospf
[SwitchE-ospf-1] area 0
[SwitchE-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255
[SwitchE-ospf-1-area-0.0.0.0] network 10.4.1.0 0.0.0.255
[SwitchE-ospf-1-area-0.0.0.0] quit
[SwitchE-ospf-1] quit
3. Configure BGP to redistribute OSPF routes and direct routes:
# Configure Switch B.
[SwitchB] bgp 200
[SwitchB-bgp] peer 11.1.1.2 as 100
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] import-route ospf
[SwitchB-bgp-ipv4] import-route direct
[SwitchB-bgp ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C.
[SwitchC] bgp 100
[SwitchC-bgp] peer 11.1.1.1 as 200
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] import-route ospf
[SwitchC-bgp-ipv4]import-route direct
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
4. Configure Switch B and Switch C to redistribute BGP routes into OSPF:
# Configure OSPF to redistribute routes from BGP on Switch B.
[SwitchB] ospf
[SwitchB-ospf-1] import-route bgp
# Configure OSPF to redistribute routes from BGP on Switch C.
[SwitchC] ospf
[SwitchC-ospf-1] import-route bgp
# Display the OSPF routing table on Switch A.
[SwitchA] 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
102
10.1.1.0/24 OSPF 150 1 11.2.1.1 Vlan100
10.2.1.0/24 OSPF 150 1 11.2.1.1 Vlan100
10.3.1.0/24 OSPF 150 1 11.2.1.1 Vlan100
10.4.1.0/24 OSPF 150 1 11.2.1.1 Vlan100
11.2.1.0/24 Direct 0 0 11.2.1.2 Vlan100
11.2.1.0/32 Direct 0 0 11.2.1.2 Vlan100
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 Vlan100
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 Switch B to advertise a summary route 10.0.0.0/8.
[SwitchB-ospf-1] asbr-summary 10.0.0.0 8
# Display the IP routing table on Switch A.
[SwitchA] 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 OSPF 150 2 11.2.1.1 Vlan100
11.2.1.0/24 Direct 0 0 11.2.1.2 Vlan100
11.2.1.0/32 Direct 0 0 11.2.1.2 Vlan100
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 Vlan100
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.
OSPF stub area configuration example
Network requirements
•
Enable OSPF on all switches, and split the AS into three areas.
•
Configure Switch A and Switch B as ABRs to forward routing information between areas.
•
Configure Switch D as the ASBR to redistribute static routes.
103
•
Configure Area 1 as a stub area to reduce advertised LSAs without influencing reachability.
Figure 25 Network diagram
Switch A
Vlan-int100
10.1.1.1/24
Area 0
Vlan-int200
10.2.1.1/24
Vlan-int100
10.1.1.2/24
Switch B
Vlan-int200
10.3.1.1/24
Area 1
Stub
Vlan-int200
10.2.1.2/24
Switch C
Vlan-int300
10.4.1.1/24
Area 2
Vlan-int200
10.3.1.2/24
Vlan-int300
10.5.1.1/24 Switch D
ASBR
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2.
Enable OSPF (see " Basic OSPF configuration example ").
3. Configure route redistribution:
# Configure Switch D to redistribute static routes.
<SwitchD> system-view
[SwitchD] ip route-static 3.1.2.1 24 10.5.1.2
[SwitchD] ospf
[SwitchD-ospf-1] import-route static
[SwitchD-ospf-1] quit
# Display ABR/ASBR information on Switch C.
<SwitchC> display ospf abr-asbr
OSPF Process 1 with Router ID 10.4.1.1
Routing Table to ABR and ASBR
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 table on Switch C.
<SwitchC> display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
10.2.1.0/24 3 Transit 10.2.1.2 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
104
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 Switch C's routing table contains an AS external route.
4. Configure Area 1 as a stub area:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ospf
[SwitchA-ospf-1] area 1
[SwitchA-ospf-1-area-0.0.0.1] stub
[SwitchA-ospf-1-area-0.0.0.1] quit
[SwitchA-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] stub
[SwitchC-ospf-1-area-0.0.0.1] quit
[SwitchC-ospf-1] quit
# Display OSPF routing information on Switch C
[SwitchC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Tables
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 10.2.1.2 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.
# Configure Area 1 as a totally stub area.
[SwitchA] ospf
[SwitchA-ospf-1] area 1
[SwitchA-ospf-1-area-0.0.0.1] stub no-summary
[SwitchA-ospf-1-area-0.0.0.1] quit
# Display OSPF routing information on Switch C.
[SwitchC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
105
Routing Tables
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 10.2.1.2 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 Switch C.
OSPF NSSA area configuration example)
Network requirements
•
Configure OSPF on all switches and split AS into three areas.
•
Configure Switch A and Switch B as ABRs to forward routing information between areas.
•
Configure Area 1 as an NSSA area and configure Switch C as an ASBR to redistribute static routes into the AS.
Figure 26 Network diagram
Switch A
Vlan-int100
10.1.1.1/24
Area 0
Vlan-int100
10.1.1.2/24
Vlan-int200
10.2.1.1/24
Switch B
Vlan-int200
10.3.1.1/24
Area 1
NSSA
Vlan-int200
10.2.1.2/24
ASBR
Switch C
Vlan-int300
10.4.1.1/24
Area 2
Vlan-int300
10.5.1.1/24
Vlan-int200
10.3.1.2/24
Switch D
Configuration procedure
1. Configure IP addresses for interfaces.
2.
Enable OSPF (see " Basic OSPF configuration example ").
3. Configure Area 1 as an NSSA area:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ospf
[SwitchA-ospf-1] area 1
[SwitchA-ospf-1-area-0.0.0.1] nssa
[SwitchA-ospf-1-area-0.0.0.1] quit
[SwitchA-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
106
[SwitchC] ospf
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] nssa
[SwitchC-ospf-1-area-0.0.0.1] quit
[SwitchC-ospf-1] quit
# Display OSPF routing information on Switch C.
[SwitchC] display ospf routing
OSPF Process 1 with Router ID 10.4.1.1
Routing Tables
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 Switch C to redistribute static routes.
[SwitchC] ip route-static 3.1.3.1 24 10.4.1.2
[SwitchC] ospf
[SwitchC-ospf-1] import-route static
[SwitchC-ospf-1] quit
# Display OSPF routing information on Switch D.
<SwitchD> display ospf routing
OSPF Process 1 with Router ID 10.5.1.1
Routing Tables
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
3.1.3.0/24 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 external route imported from the NSSA area exists on Switch D.
107
OSPF DR election configuration example
Network requirements
•
Enable OSPF on Switches A, B, C, and D on the same network.
•
Configure Switch A as the DR, and configure Switch C as the BDR.
Figure 27 Network diagram
Switch A Switch B
DR
Vlan-int1
192.168.1.1/24
Vlan-int1
192.168.1.2/24
Vlan-int1
192.168.1.3/24
Switch C
Vlan-int1
192.168.1.4/24
BDR
Switch D
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] router id 1.1.1.1
[SwitchA] ospf
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] router id 2.2.2.2
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] router id 3.3.3.3
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
# Configure Switch D.
108
<SwitchD> system-view
[SwitchD] router id 4.4.4.4
[SwitchD] ospf
[SwitchD-ospf-1] area 0
[SwitchD-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] quit
[SwitchD-ospf-1] return
# Display OSPF neighbor information of Switch A.
[SwitchA] 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(Vlan-interface1)'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 ]
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 ]
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 ]
BFD status: Disabled
The output shows that Switch D is the DR and Switch C is the BDR.
3. Configure router priorities on interfaces:
# Configure Switch A.
[SwitchA] interface vlan-interface 1
[SwitchA-Vlan-interface1] ospf dr-priority 100
[SwitchA-Vlan-interface1] quit
# Configure Switch B.
[SwitchB] interface vlan-interface 1
109
[SwitchB-Vlan-interface1] ospf dr-priority 0
[SwitchB-Vlan-interface1] quit
# Configure Switch C.
[SwitchC] interface vlan-interface 1
[SwitchC-Vlan-interface1] ospf dr-priority 2
[SwitchC-Vlan-interface1] quit
# Display neighbor information of Switch D.
<SwitchD> 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(Vlan-interface1)'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 ]
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 ]
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 ]
BFD status: Disabled
The output shows that the DR and BDR are not changed, because the priority settings do not take effect immediately.
4. Restart OSPF process:
# Restart the OSPF process of Switch D.
<SwitchD> reset ospf 1 process
Warning : Reset OSPF process? [Y/N]:y
# Display neighbor information of Switch D.
<SwitchD> display ospf peer verbose
110
OSPF Process 1 with Router ID 4.4.4.4
Neighbors
Area 0.0.0.0 interface 192.168.1.4(Vlan-interface1)'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 ]
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 ]
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 ]
BFD status: Disabled
If the neighbor state is full, Switch D has established an adjacency with the neighbor. If the neighbor state is 2-way , the two switches are not the DR or the BDR, and they do not exchange
LSAs.
# Display OSPF interface information.
[SwitchA] display ospf interface
OSPF Process 1 with Router ID 1.1.1.1
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
[SwitchB] display ospf interface
OSPF Process 1 with Router ID 2.2.2.2
Interfaces
Area: 0.0.0.0
111
IP Address Type State Cost Pri DR BDR
192.168.1.2 Broadcast DROther 1 0 192.168.1.1 192.168.1.3
The interface state DROther means the interface is not the DR or BDR.
OSPF virtual link configuration example
Network requirements
As shown in Figure 28 , configure a virtual link between Switch B and Switch C to connect Area 2 to
the backbone area. After configuration, Switch B can learn routes to Area 2.
Figure 28 Network diagram
Area 1
Virtual link
Switch B
Vlan-int200
10.2.1.1/24
Area 0
Vlan-int300
10.1.1.2/24
Vlan-int300
10.1.1.1/24
Switch D
Vlan-int100
10.3.1.1/24
Vlan-int100
10.3.1.2/24
Area 2
Switch C
Vlan-int200
10.2.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ospf 1 router-id 1.1.1.1
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ospf 1 router-id 2.2.2.2
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] area 1
[SwitchB–ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[SwitchB–ospf-1-area-0.0.0.1] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf 1 router-id 3.3.3.3
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.1] quit
[SwitchC-ospf-1] area 2
[SwitchC–ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
Switch A
112
[SwitchC–ospf-1-area-0.0.0.2] quit
[SwitchC-ospf-1] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] ospf 1 router-id 4.4.4.4
[SwitchD-ospf-1] area 2
[SwitchD-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.2] quit
# Display the OSPF routing table on Switch B.
[SwitchB] display ospf routing
OSPF Process 1 with Router ID 2.2.2.2
Routing Tables
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
Area 0 has no direct connection to Area 2, so the routing table of Switch B has no route to Area
2.
3. Configure a virtual link:
# Configure Switch B.
[SwitchB] ospf
[SwitchB-ospf-1] area 1
[SwitchB-ospf-1-area-0.0.0.1] vlink-peer 3.3.3.3
[SwitchB-ospf-1-area-0.0.0.1] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
[SwitchC] ospf 1
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] vlink-peer 2.2.2.2
[SwitchC-ospf-1-area-0.0.0.1] quit
# Display the OSPF routing table on Switch B.
[SwitchB] display ospf routing
OSPF Process 1 with Router ID 2.2.2.2
Routing Tables
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 Switch B has learned the route 10.3.1.0/24 to Area 2.
113
OSPF GR configuration example
Network requirements
•
Switch A, Switch B, and Switch C that belong to the same AS and the same OSPF routing domain are GR capable.
•
Switch A acts as the non-IETF GR restarter. Switch B and Switch C are the GR helpers, and synchronize their LSDBs with Switch A through OOB communication of GR.
Figure 29 Network diagram
Router ID: 1.1.1.1
GR restarter
Switch A
Vlan-int100
192.1.1.1/24
Vlan-int100
192.1.1.2/24
Switch B
Vlan-int100
192.1.1.3/24
Switch C
GR helper
Router ID: 2.2.2.2
Configuration procedure
GR helper
Router ID: 3.3.3.3
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
SwitchA> system-view
[SwitchA] router id 1.1.1.1
[SwitchA] ospf 100
[SwitchA-ospf-100] area 0
[SwitchA-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[SwitchA-ospf-100-area-0.0.0.0] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] router id 2.2.2.2
[SwitchB] ospf 100
[SwitchB-ospf-100] area 0
[SwitchB-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[SwitchB-ospf-100-area-0.0.0.0] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] router id 3.3.3.3
[SwitchC] ospf 100
[SwitchC-ospf-100] area 0
[SwitchC-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[SwitchC-ospf-100-area-0.0.0.0] quit
3. Configure OSPF GR:
114
# Configure Switch 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 capability for OSPF process 100.
[SwitchA-ospf-100] enable link-local-signaling
[SwitchA-ospf-100] enable out-of-band-resynchronization
[SwitchA-ospf-100] graceful-restart
[SwitchA-ospf-100] return
# Configure Switch B as the GR helper: enable the link-local signaling capability and the out-of-band re-synchronization capability for OSPF process 100.
[SwitchB-ospf-100] enable link-local-signaling
[SwitchB-ospf-100] enable out-of-band-resynchronization
# Configure Switch C as the GR helper: enable the link-local signaling capability and the out-of-band re-synchronization capability for OSPF process 100.
[SwitchC-ospf-100] enable link-local-signaling
[SwitchC-ospf-100] enable out-of-band-resynchronization
Verifying the configuration
# Enable OSPF GR event debugging and restart the OSPF process by using GR on Switch A.
<SwitchA> debugging ospf event graceful-restart
<SwitchA> terminal monitor
<SwitchA> terminal logging level 7
<SwitchA> reset ospf 100 process graceful-restart
Reset OSPF process? [Y/N]:y
%Oct 21 15:29:28:727 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(Vlan-interface100) from Full to Down.
%Oct 21 15:29:28:729 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(Vlan-interface100) from Full to Down.
*Oct 21 15:29:28:735 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 nonstandard GR Started for OSPF Router
*Oct 21 15:29:28:735 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 created GR wait timer,timeout interval is 40(s).
*Oct 21 15:29:28:735 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 created GR Interval timer,timeout interval is 120(s).
*Oct 21 15:29:28:758 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 created OOB Progress timer for neighbor 192.1.1.3.
*Oct 21 15:29:28:766 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 created OOB Progress timer for neighbor 192.1.1.2.
%Oct 21 15:29:29:902 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(Vlan-interface100) from Loading to Full.
*Oct 21 15:29:29:902 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.2.
%Oct 21 15:29:30:897 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(Vlan-interface100) from Loading to Full.
*Oct 21 15:29:30:897 2011 SwitchA OSPF/7/DEBUG:
OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.3.
*Oct 21 15:29:30:911 2011 SwitchA 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 SwitchA OSPF/7/DEBUG:
OSPF 100 deleted GR Interval timer.
*Oct 21 15:29:30:912 2011 SwitchA OSPF/7/DEBUG:
115
OSPF 100 deleted GR wait timer.
%Oct 21 15:29:30:920 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(Vlan-interface100) from Full to Down.
%Oct 21 15:29:30:921 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(Vlan-interface100) from Full to Down.
%Oct 21 15:29:33:815 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.3(Vlan-interface100) from Loading to Full.
%Oct 21 15:29:35:578 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor
192.1.1.2(Vlan-interface100) from Loading to Full.
The output shows that Switch A completes GR.
OSPF NSR configuration example
Network requirements
As shown in Figure 30 , Switch S, Switch A, and Switch B belong to the same OSPF routing domain.
Enable OSPF NSR on Switch S to ensure correct routing when an active/standby switchover occurs on Switch S.
Figure 30 Network diagram
Loop 0
22.22.22.22/32
Switch A
Vlan-int100
12.12.12.1/24
Vlan-int100
12.12.12.2/24
Switch S
Vlan-int200
14.14.14.1/24
Vlan-int200
14.14.14.2/24
Switch B
Loop 0
44.44.44.44/32
Configuration procedure
1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
2. Configure OSPF on the switches to ensure the following: (Details not shown.)
ï‚¡
Switch S, Switch A, and Switch B can communicate with each other at Layer 3.
ï‚¡
Dynamic route update can be implemented among them with OSPF.
3. Enable OSPF NSR on Switch S.
<SwitchS> system-view
[SwitchS] ospf 100
[SwitchS-ospf-100] non-stop-routing
[SwitchS-ospf-100] quit
Verifying the configuration
# Perform an active/standby switchover on Switch S.
[SwitchS] 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
116
staticroute 0/0 0/0 eviisis 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 Switch A to verify the neighbor relationship between Switch A and Switch S.
<SwitchA> 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 Vlan100
# Display OSPF routes on Switch A to verify if Switch A has a route to the loopback interface on
Switch B.
<SwitchA> display ospf routing
OSPF Process 1 with Router ID 2.2.2.1
Routing Tables
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
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 Switch B to verify the neighbor relationship between Switch B and
Switch S.
<SwitchB> 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 Vlan200
# Display OSPF routes on Switch B to verify if Switch B has a route to the loopback interface on
Switch A.
<SwitchB> display ospf routing
OSPF Process 1 with Router ID 4.4.4.1
117
Routing Tables
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 that when an active/standby switchover occurs on Switch S, the neighbor relationships and routing information on Switch A and Switch B have not changed, and the traffic from Switch A to Switch B has not been impacted.
BFD for OSPF configuration example
Network requirements
As shown in Figure 31 , run OSPF on Switch A, Switch B, and Switch C so that they are reachable to
each other at the network layer.
•
When the link over which Switch A and Switch B communicate through a Layer 2 switch fails,
BFD can quickly detect the failure and notify OSPF of the failure.
•
Switch A and Switch B then communicate through Switch C.
Figure 31 Network diagram
Loop0
Switch A
Vlan-int10
Vlan-int11
BFD
L2 Switch
Vlan-int10
Switch B
Vlan-int13
Loop0
Area 0
Vlan-int11 Vlan-int13
Switch C
Table 9 Interface and IP address assignment
Device
Switch A
Switch A
Switch A
Switch B
Switch B
Switch B
Switch C
Interface
Vlan-int10
Vlan-int11
Loop0
Vlan-int10
Vlan-int13
Loop0
Vlan-int11
118
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
Switch C
Configuration procedure
Interface
Vlan-int13
IP address
13.1.1.2/24
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable OSPF:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ospf
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 192.168.0.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] network 121.1.1.1 0.0.0.0
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 192.168.0.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] network 13.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] network 120.1.1.1 0.0.0.0
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 13.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
3. Configure BFD:
# Enable BFD on Switch A and configure BFD parameters.
[SwitchA] bfd session init-mode active
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ospf bfd enable
[SwitchA-Vlan-interface10] bfd min-transmit-interval 500
[SwitchA-Vlan-interface10] bfd min-receive-interval 500
[SwitchA-Vlan-interface10] bfd detect-multiplier 7
[SwitchA-Vlan-interface10] quit
[SwitchA] quit
# Enable BFD on Switch B and configure BFD parameters.
[SwitchB] bfd session init-mode active
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ospf bfd enable
[SwitchB-Vlan-interface10] bfd min-transmit-interval 500
119
[SwitchB-Vlan-interface10] bfd min-receive-interval 500
[SwitchB-Vlan-interface10] bfd detect-multiplier 6
Verifying the configuration
# Display the BFD information on Switch A.
<SwitchA> 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 Vlan10
# Display routes destined for 120.1.1.1/32 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: OSPF Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 2 Preference: 10
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
Tunnel ID: Invalid Interface: Vlan-interface10
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails.
# Display routes destined for 120.1.1.1/32 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: OSPF Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 4 Preference: 10
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
120
Flags: 0x1008c OrigNextHop: 10.1.1.100
Label: NULL RealNextHop: 10.1.1.100
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface11
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
OSPF FRR configuration example
Network requirements
As shown in Figure 32 , Switch A, Switch B, and Switch C reside in the same OSPF domain.
Configure OSPF FRR so that when the link between Switch A and Switch B fails, traffic is immediately switched to Link B.
Figure 32 Network diagram
Switch C
Vlan
-int
100
Vlan
-int
101
Link B
Vlan
-int
100
Link A
Loop0
Switch A
Vlan-int200
Table 10 Interface and IP address assignment
Vlan
-int
101
Vlan-int200
Switch B
Loop0
Device
Switch A
Switch A
Switch A
Switch B
Switch B
Switch B
Switch C
Interface
Vlan-int100
Vlan-int200
Loop0
Vlan-int101
Vlan-int200
Loop0
Vlan-int100
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
Switch C
Configuration procedure
Vlan-int101 24.24.24.2/24
1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
2. Configure OSPF on the switches to ensure that Switch A, Switch B, and Switch C can communicate with each other at the network layer. (Details not shown.)
3. Configure OSPF FRR to automatically calculate the backup next hop:
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.
ï‚¡ (Method 1.) Enable OSPF FRR to calculate the backup next hop by using the LFA algorithm:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bfd echo-source-ip 2.2.2.2
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ï‚¡
[SwitchA] ospf 1
[SwitchA-ospf-1] fast-reroute lfa
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 3.3.3.3
[SwitchB] ospf 1
[SwitchB-ospf-1] fast-reroute lfa
[SwitchB-ospf-1] quit
(Method 2.) Enable OSPF FRR to designate a backup next hop by using a routing policy.
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bfd echo-source-ip 1.1.1.1
[SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32
[SwitchA] route-policy frr permit node 10
[SwitchA-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchA-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
100 backup-nexthop 12.12.12.2
[SwitchA-route-policy-frr-10] quit
[SwitchA] ospf 1
[SwitchA-ospf-1] fast-reroute route-policy frr
[SwitchA-ospf-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 4.4.4.4
[SwitchB] ip prefix-list abc index 10 permit 1.1.1.1 32
[SwitchB] route-policy frr permit node 10
[SwitchB-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchB-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
101 backup-nexthop 24.24.24.2
[SwitchB-route-policy-frr-10] quit
[SwitchB] ospf 1
[SwitchB-ospf-1] fast-reroute route-policy frr
[SwitchB-ospf-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.
[SwitchA] display ip routing-table 4.4.4.4 verbose
Summary Count : 1
Destination: 4.4.4.4/32
Protocol: OSPF Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 10
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NBRID: 0x26000002 LastAs: 0
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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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface100
# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.
[SwitchB] display ip routing-table 1.1.1.1 verbose
Summary Count : 1
Destination: 1.1.1.1/32
Protocol: OSPF Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 1 Preference: 10
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NBRID: 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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface101
Troubleshooting OSPF configuration
No OSPF neighbor relationship established
Symptom
No OSPF neighbor relationship can be established.
Analysis
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.)
Solution
To resolve the problem:
1. Use the display ospf peer command to verify OSPF neighbor information.
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 at least four times the hello interval.
5. On an NBMA network, use the peer ip-address command to manually specify the neighbor.
6. At least one interface must have a router priority higher than 0 on an NBMA or a broadcast network.
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7. If the problem persists, contact Hewlett Packard Enterprise Support.
Incorrect routing information
Symptom
Analysis
OSPF cannot find routes to other areas.
The backbone area must maintain connectivity to all other areas. If a router connects to more than one area, at least 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, at least 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.
124
Configuring IS-IS
Overview
Intermediate System-to-Intermediate System (IS-IS) is a dynamic routing protocol designed by the
ISO to operate on the connectionless network protocol (CLNP).
IS-IS was modified and extended in RFC 1195 by the IETF for application in both TCP/IP and OSI reference models, called "Integrated IS-IS" or "Dual 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 at least 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 format
NSAP
As shown in Figure 33 , 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 —Identifies the type of service.
The IDP and DSP are variable in length. The length of an NSAP address ranges from 8 bytes to 20 bytes.
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Figure 33 NSAP address format
IDP DSP
System ID (6 octet) AFI IDI HO-DSP SEL (1 octet)
Area address
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:
1. Extend each decimal number of the IP address to three digits by adding 0s from the left, such as
168.010.001.001.
2. 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
The N-SEL, or the NSAP selector (SEL), is similar to the protocol identifier in IP. Different transport layer protocols correspond to different SELs. All SELs in IP are 00.
Routing method
The IS-IS address format identifies the area, so a Level-1 router can easily identify packets destined to other areas. IS-IS routers perform routing as follows:
•
A Level-1 router performs intra-area routing according to the system ID. If the destination address of a packet does not belong to the local area, the Level-1 router forwards it to the nearest Level-1-2 router.
•
A Level-2 router performs inter-area routing according to the area address.
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 ranges from 8 bytes 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.
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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.
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 and Level-2
•
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.
Figure 34 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 34 IS-IS topology 1
Area 3
Area 2
L1/L2
L1 L2
Area 4
L2
L1/L2
L2
Area 1
L2
L1/L2
Area 5
L1/L2 L1
L1
L1 L1
L1
Figure 35 shows another IS-IS topology. The Level-1-2 routers connect to the Level-1 and Level-2
routers, and form the IS-IS backbone together with the Level-2 routers. No area is defined as the
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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 35 IS-IS topology 2
Area 1
L2
Area 2
L1
Area 4
L1/L2
L1 L1/L2 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-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 Level-1 areas and the Level-2 area to a Level-1 area, so 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 Level-1 areas and the
Level-2 area to the connected Level-1 area so that the Level-1 routers can select the optimal routes for packets.
IS-IS network types
Network types
IS-IS supports broadcast networks (for example, Ethernet and Token Ring) and point-to-point networks (for example, PPP and HDLC).
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.
•
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.
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As shown in Figure 36 , the same level routers on a network, including non-DIS routers, establish
adjacency with each other.
Figure 36 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 37 PDU format
PDU common header
Table 11 PDU types
PDU specific header Variable length fields (CLV)
Type
15
20
24
25
16
17
18
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
Level-2 Complete Sequence Numbers PDU
Acronym
L1 LAN IIH
L2 LAN IIH
P2P IIH
L1 LSP
L2 LSP
L1 CSNP
L2 CSNP
129
Type
26
PDU Type
Level-1 Partial Sequence Numbers PDU
Acronym
L1 PSNP
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
27
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 38 CLV format
Code
No. of Octets
1
Length 1
Value Length
Table 12 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), and others are defined in RFC 1195.
Table 12 CLV codes and PDU types
CLV Code
1
8
9
10
2
4
6
7
Name
Area Addresses
IS Neighbors (LSP)
Partition Designated Level 2 IS
IS Neighbors (MAC Address)
IS Neighbors (SNPA Address)
Padding
LSP Entries
Authentication Information
PDU Type
IIH, LSP
LSP
L2 LSP
LAN IIH
LAN IIH
IIH
SNP
IIH, LSP, SNP
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CLV Code
128
129
130
131
132
Name
IP Internal Reachability Information
Protocols Supported
IP External Reachability Information
Inter-Domain Routing Protocol Information
IP Interface Address
PDU Type
LSP
IIH, LSP
L2 LSP
L2 LSP
IIH, LSP
Protocols and standards
•
ISO 10589 ISO IS-IS Routing Protocol
•
ISO 9542 ES-IS Routing Protocol
•
ISO 8348/Ad2 Network Services Access Points
•
RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
•
RFC 2763, Dynamic Hostname Exchange Mechanism for IS-IS
•
RFC 2966, Domain-wide Prefix Distribution with Two-Level IS-IS
•
RFC 2973, IS-IS Mesh Groups
•
RFC 3277, IS-IS Transient Blackhole Avoidance
•
RFC 3358, Optional Checksums in ISIS
•
RFC 3373, Three-Way Handshake for IS-IS Point-to-Point Adjacencies
•
RFC 3567, Intermediate System to Intermediate System (IS-IS) Cryptographic Authentication
•
RFC 3719, Recommendations for Interoperable Networks using IS-IS
•
RFC 3786, Extending the Number of IS-IS LSP Fragments Beyond the 256 Limit
•
RFC 3787, Recommendations for Interoperable IP Networks using IS-IS
•
RFC 3847, Restart Signaling for IS-IS
•
RFC 4444, Management Information Base for Intermediate System to Intermediate System
(IS-IS)
IS-IS configuration task list
Tasks at a glance
•
•
(Optional.) Configuring the IS level and circuit level
•
(Optional.) Configuring P2P network type for an interface
(Optional.) Configuring IS-IS route control :
•
•
Specifying a preference for IS-IS
•
Configuring the maximum number of ECMP routes
•
Configuring IS-IS route summarization
•
•
Configuring IS-IS route redistribution
•
Configuring IS-IS route filtering
•
Configuring IS-IS route leaking
131
Tasks at a glance
(Optional.) Tuning and optimizing IS-IS networks :
•
Specifying the interval for sending IS-IS hello packets
•
Specifying the IS-IS hello multiplier
•
Specifying the interval for sending IS-IS CSNP packets
•
Configuring a DIS priority for an interface
•
Enabling source address check for hello packets on a PPP interface
•
Disabling an interface from sending/receiving IS-IS packets
•
Enabling an interface to send small hello packets
•
•
Controlling SPF calculation interval
•
Configuring convergence priorities for specific routes
•
•
Configuring system ID to host name mappings
•
Enabling the logging of neighbor state changes
•
•
Configuring IS-IS network management
(Optional.) Enhancing IS-IS network security :
•
Configuring neighbor relationship authentication
•
Configuring area authentication
•
Configuring routing domain authentication
(Optional.) Configuring IS-IS GR
(Optional.) Configuring IS-IS NSR
(Optional.) Configuring BFD for IS-IS
(Optional.) Configuring IS-IS FRR
Configuring basic IS-IS
Configuration prerequisites
Before the configuration, complete the following tasks:
•
Configure the link layer protocol.
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
Enabling IS-IS
Step
1. Enter system view.
2. Create an IS-IS process and enter its view.
3. Assign a NET.
4. Return to system view.
5. Enter interface view.
Command system-view isis [ process-id ]
[ vpn-instance vpn-instance-name ] network-entity net quit interface interface-type interface-number
Remarks
N/A
By default, the IS-IS process is disabled.
By default, NET is not assigned.
N/A
N/A
132
Step
6. Enable an IS-IS process on the interface.
Command isis enable [ process-id ]
Remarks
By default, no IS-IS process is enabled.
Configuring the IS level and circuit level
Follow these guidelines when you configure the IS level for routers in only one area:
•
Configure the IS level of all routers as Level-1 or Level-2 rather than different levels because the routers do not need to maintain two identical LSDBs.
•
Configure the IS level as 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, configure the circuit level for its interfaces as Level-1 or
Level-2. This will limit neighbor relationship establishment.
To configure the IS level and circuit level:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Specify the IS level.
4. Return to system view.
5. Enter interface view.
6. Specify the circuit level.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A is-level { level-1 | level-1-2 | level-2 } quit interface interface-type
interface-number
By default, the IS level is Level-1-2.
N/A
N/A 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
Perform this task only for a broadcast network that has up to two attached routers.
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, configure the network type of attached interfaces as
P2P to avoid DIS election and CSNP flooding, saving network bandwidth and speeding up network convergence.
To configure P2P network type for an interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
133
Step Command
3. Configure P2P network type for an interface. isis circuit-type p2p
Remarks
By default, the network type of an interface depends on the physical media. The network type of a VLAN interface is broadcast.
Configuring IS-IS route control
Configuration prerequisites
Before the configuration, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable IS-IS.
Configuring IS-IS link cost
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.
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 13 applies.
Configure the expected bandwidth of an interface with the bandwidth command. For more information, see Interface Command Reference .
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 IS-IS cost for an interface
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
134
Step
3. (Optional.) Specify an
IS-IS cost style.
Command cost-style { narrow | wide | wide-compatible | { compatible | narrow-compatible } [ relax-spf-limit ] }
Remarks
By default, the IS-IS cost type is narrow .
4. Return to system view.
5. Enter interface view.
quit N/A interface interface-type interface-number N/A
6. (Optional.) Specify a cost for the IS-IS interface.
Configuring a global IS-IS cost isis cost value [ level-1 | level-2 ]
By default, no cost for the interface is specified.
Step Command
1. Enter system view. system-view
2. Enter IS-IS view.
3. (Optional.) Specify an IS-IS cost style. isis [ process-id ] [ vpn-instance vpn-instance-name ] cost-style { narrow | wide | wide-compatible |
{ compatible | narrow-compatible }
[ relax-spf-limit ] }
4. Specify a global
IS-IS cost. circuit-cost value [ level-1 | level-2 ]
Enabling automatic IS-IS cost calculation
Remarks
N/A
N/A
By default, the IS-IS cost style is narrow .
By default, no global cost is specified.
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] cost-style { wide | wide-compatible }
3. Specify an IS-IS cost style.
4. Enable automatic IS-IS cost calculation.
5. (Optional.) Configure a bandwidth reference value for automatic IS-IS cost calculation. auto-cost enable bandwidth-reference value
Remarks
N/A
N/A
By default, the IS-IS cost is narrow .
By default, automatic IS-IS cost calculation is disabled.
The default setting is 100 Mbps.
Specifying a preference for IS-IS
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 ."
To configure a preference for IS-IS:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
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Step
3. Configure a preference for
IS-IS.
Command preference { preference | route-policy route-policy-name } *
Remarks
The default setting is
15.
Configuring the maximum number of ECMP routes
Perform this task to implement load sharing over ECMP routes.
To configure the maximum number of ECMP routes:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the maximum number of ECMP routes.
Remarks
N/A
N/A
maximum load-balancing number
By default, the maximum number of IS-IS ECMP routes equals the maximum number of ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of ECMP routes supported by the system. For more information about the max-ecmp-num command, see Layer 3—IP
Routing Command Reference.
Configuring IS-IS route summarization
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. The cost of the summary route is the lowest one among the costs of the more-specific routes.
To configure route summarization:
Remarks
N/A
Step Command
1. Enter system view. system-view
2. Enter IS-IS view.
3. Configure IS-IS route summarization. isis [ process-id ] [ vpn-instance vpn-instance-name ] summary ip-address { mask-length | mask } [ avoid-feedback | generate_null0_route | [ level-1 | level-1-2 | level-2 ] | tag tag ] *
N/A
By default, route summarization is not configured.
Advertising a default route
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.
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To advertise a default route:
Step Command
1. Enter system view. system-view
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Advertise a default route. default-route-advertise [ [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name ] *
Remarks
N/A
N/A
By default, IS-IS does not advertise a default route.
Configuring IS-IS route redistribution
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.
To configure IS-IS route redistribution from other routing protocols:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Redistribute routes from other routing protocols or other IS-IS processes. import-route protocol [ process-id |
all-processes | allow-ibgp ] [ cost cost | cost-type { external | internal } | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
By default, no route is redistributed.
By default, if no level is specified, this command redistributes routes into the Level-2 routing table.
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 not configured.
Configuring IS-IS route filtering
You can use an ACL, IP prefix list, or routing policy to filter routes calculated using received LSPs and routes redistributed from other routing protocols.
Filtering routes calculated from received LSPs
IS-IS saves LSPs received from neighbors in the LSDB, uses the SPF algorithm to calculate the shortest path tree with itself as the root, and installs the routes to the IS-IS routing table. IS-IS installs 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.
To filter routes calculated using received LSPs:
Step
1. Enter system view.
Command system-view
Remarks
N/A
137
Step
2. Enter IS-IS view.
Command isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
3. Filter routes calculated using received LSPs. filter-policy { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } import
By default, IS-IS route filtering is not configured.
Filtering redistributed routes
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.
To filter redistributed routes:
Step
1. Enter system view.
Remarks
N/A
2. Enter IS-IS view.
3. Filter routes redistributed from other routing protocols or IS-IS processes.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] filter-policy { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } export [ protocol
[ process-id ] ]
N/A
By default, IS-IS route filtering is not configured.
Configuring IS-IS route leaking
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.
To configure IS-IS route leaking:
Step
1. Enter system view.
Remarks
N/A
2. Enter IS-IS view.
3. Configure route leaking from Level-1 to Level-2.
4. Configure route leaking from Level-2 to Level-1.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] import-route isis level-1 into level-2
[ filter-policy { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] * import-route isis level-2 into level-1
[ filter-policy { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
N/A
By default, IS-IS advertises routes from
Level-1 to Level-2.
By default, IS-IS does not advertise routes from
Level-2 to Level-1.
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Tuning and optimizing IS-IS networks
Configuration prerequisites
Before you tune and optimize IS-IS networks, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable IS-IS.
Specifying the interval for sending IS-IS hello packets
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.
To specify the interval for sending hello packets:
Step
1. Enter system view.
2. Enter interface view.
3. Specify the interval for sending hello packets.
Command system-view
Remarks
N/A interface interface-type interface-number
N/A
isis timer hello seconds [ level-1
| level-2 ]
The default setting is 10 seconds.
The interval between hello packets sent by the DIS is 1/3 the hello interval set with the isis timer hello command.
Specifying the IS-IS hello multiplier
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.
To specify the IS-IS hello multiplier:
Step
1. Enter system view.
2. Enter interface view.
3. Specify the hello multiplier.
Command system-view interface interface-type interface-number isis timer holding-multiplier value
[ level-1 | level-2 ]
Remarks
N/A
N/A
The default setting is
3.
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Specifying the interval for sending IS-IS CSNP packets
On a broadcast network, perform this task on the DIS that uses CSNP packets to synchronize
LSDBs.
To specify the interval for sending IS-IS CSNP packets:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
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.
Configuring a DIS priority for an interface
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.
To configure a DIS priority for an interface:
Step
1. Enter system view.
2. Enter interface view.
3. Configure a DIS priority for the interface.
Command system-view interface interface-type interface-number
isis dis-priority value [ level-1 | level-2 ]
Remarks
N/A
N/A
The default setting is 64.
Enabling source address check for hello packets on a PPP interface
An IS-IS PPP interface can have a peer on a different network. Perform this task to configure an
IS-IS PPP interface to establish neighbor relationship only with a peer on the same network.
To enable source address check for hello packets on a PPP interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Enable source address check for hello packets on a
PPP interface. isis peer-ip-check
By default, an IS-IS PPP interface can have a peer on a different network.
The command applies only to
PPP interfaces.
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Disabling an interface from sending/receiving IS-IS packets
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.
To disable an interface from sending and receiving IS-IS packets:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
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
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.
To enable an interface to send small hello packets:
Remarks
N/A
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
3. Enable the interface to send small hello packets without
CLVs. isis small-hello
N/A
By default, the interface can send standard hello packets.
Configuring LSP parameters
Configuring LSP timers
1. Specify the maximum age of LSPs.
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.
To specify the maximum age of LSPs:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Specify the maximum LSP age.
timer lsp-max-age seconds
2. Specify the LSP refresh interval and generation interval.
N/A
The default setting is 1200 seconds.
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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 the network topology changes, for example, a neighbor is down or up, or the interface metric, system ID, or area ID is changed, 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.
When network changes are not frequent, the minimum-interval is adopted. If network changes n-2 become frequent, the LSP generation interval is incremented by incremental-interval × 2 (n is the number of calculation times) each time a generation occurs until the maximum-interval is reached.
To specify the LSP refresh interval and generation interval:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A
3. Specify the LSP refresh interval.
timer lsp-refresh seconds
By default, the LSP refresh interval is 900 seconds.
4. Specify 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.
3. Specify LSP sending intervals.
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.
To configure LSP sending intervals:
Step
1. Enter system view.
Command system-view
Remarks
N/A
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 ]
N/A
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.
Specifying LSP lengths
isis timer retransmit seconds
By default, the LSP retransmission interval on a P2P link is 5 seconds.
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.
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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.
To specify LSP lengths:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
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
Changed LSPs can trigger SPF recalculation. To advertise the changed LSPs before the router recalculates routes for faster network convergence, enable LSP flash flooding.
To enable LSP flash flooding:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Enable LSP flash flooding.
Enabling LSP fragment extension flash-flood [ flood-count flooding-count |
max-timer-interval flooding-interval | [ level-1 | level-2 ] ] *
By default, LSP flash flooding is disabled.
Perform this task to enable IS-IS fragment extension for an IS-IS process. The MTUs of all interfaces running the IS-IS process must not be less than 512. Otherwise, LSP fragment extension does not take effect.
To enable LSP fragment extension:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Enable LSP fragment extension.
4. Configure a virtual system ID.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] lsp-fragments-extend [ level-1 | level-1-2 | level-2 ]
Remarks
N/A
N/A
By default, this feature is disabled. virtual-system virtual-system-id
By default, no virtual system ID is configured.
Configure at least one virtual system to generate extended LSP fragments.
143
Controlling SPF calculation interval
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.
When network changes are not frequent, the minimum-interval is adopted. If network changes become frequent, the SPF calculation interval is incremented by incremental-interval × 2 n-2
(n is the number of calculation times) each time a calculation occurs until the maximum-interval is reached.
To control SPF calculation interval:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Configure the SPF calculation interval.
timer spf maximum-interval
[ minimum-interval
[ incremental-interval ] ]
By default:
•
The maximum interval is
5 seconds.
•
The minimum interval is
50 milliseconds.
•
The incremental interval is 200 milliseconds.
Configuring convergence priorities for specific routes
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.
To assign convergence priorities to specific IS-IS routes:
Step
1. Enter system view.
Remarks
N/A
2. Enter IS-IS view.
3. Assign convergence priorities to specific IS-IS routes.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] priority { critical | high | medium } { prefix-list prefix-list-name | tag tag-value }
N/A
By default, IS-IS routes, except
IS-IS host routes, have the low convergence priority.
Setting the LSDB overload bit
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.
To set the LSDB overload bit:
144
Step
1. Enter system view.
2. Enter IS-IS view.
3. Set the overload bit.
Command system-view
Remarks
N/A isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A set-overload [ on-startup [ [ start-from-nbr system-id
[ timeout1 [ nbr-timeout ] ] ] | timeout2 ] [ allow { external
| interlevel } * ]
By default, the overload bit is not set.
Configuring system ID to host name mappings
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. 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
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A
3. Configure a system ID to host name mapping for a remote IS. is-name map sys-id map-sys-name
A system ID can correspond to only one host name.
Configuring dynamic system ID to host name mapping
Static system ID to host name mapping requires you to 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.
When you use 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.
To configure dynamic system ID to host name mapping:
Step
1. Enter system view.
Command 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
Remarks
N/A
N/A
By default, no host name is specified for the router.
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Step
4. Return to system view.
5. Enter interface view.
Command quit interface interface-type interface-number
Remarks
N/A
6. Configure a DIS name.
isis dis-name symbolic-name
N/A
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.
Enabling the logging of neighbor state changes
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 Network
Management and Monitoring Configuration Guide .
To enable the logging of neighbor state changes:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Enable the logging of neighbor state changes. log-peer-change
By default, the logging of neighbor state changes is enabled.
Enabling IS-IS ISPF
When the network topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT.
To enable IS-IS ISPF:
Step Command
1. Enter system view. system-view
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
3. Enable IS-IS ISPF. ispf enable
By default, IS-IS is disabled.
Configuring IS-IS network management
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.
•
Enable IS-IS notifications to report important events.
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Notifications are delivered to the SNMP module, which outputs the notifications according to the configured output rules. For more information about SNMP notifications, see Network Management and Monitoring Configuration Guide .
To configure IS-IS network management:
Step Command
1. Enter system view. system-view
2. Bind MIB to an IS-IS process.
isis mib-binding process-id
Remarks
N/A
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
N/A
By default, no context name is set for the SNMP object for managing
IS-IS.
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.
Configuration prerequisites
Before the configuration, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable IS-IS.
Configuring neighbor relationship authentication
With neighbor relationship authentication configured, an interface adds the password in the specified mode into hello packets to the peer and checks the password in the received hello packets. If the authentication succeeds, it forms the neighbor relationship with the peer.
The authentication mode and password at both ends must be identical.
To configure neighbor relationship authentication:
147
Step
1. Enter system view.
2. Enter interface view.
3. Specify the authentication mode and password.
Command system-view interface interface-type interface-number isis authentication-mode { gca key-id
{ hmac-sha-1 | hmac-sha-224 | hmac-sha-256 | hmac-sha-384 | hmac-sha-512 } | md5 | simple }
{ cipher cipher-string | plain plain-string } [ level-1 | level-2 ] [ ip | osi ]
Remarks
N/A
N/A
By default, no authentication is configured.
Configuring area authentication
Area authentication prevents the router from installing routing information from untrusted routers into the Level-1 LSDB. The router encapsulates the authentication password in the specified mode in
Level-1 packets (LSP, CSNP, and PSNP) and checks the password in received Level-1 packets.
Routers in a common area must have the same authentication mode and password.
To configure area authentication:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Specify the area authentication mode and password.
Command system-view
Remarks
N/A isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A area-authentication-mode { gca
key-id { hmac-sha-1 | hmac-sha-224
| hmac-sha-256 | hmac-sha-384 | hmac-sha-512 } | md5 | simple }
{ cipher cipher-string | plain plain-string } [ ip | osi ]
By default, no area authentication is configured.
Configuring routing domain authentication
Routing domain authentication prevents untrusted routing information from entering into a routing domain. A router with the authentication configured encapsulates the password in the specified mode into Level-2 packets (LSP, CSNP, and PSNP) and check the password in received Level-2 packets.
All the routers in the backbone must have the same authentication mode and password.
To configure routing domain authentication:
Step
1. Enter system view.
2. Enter IS-IS view.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A
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Step
3. Specify the routing domain authentication mode and password.
Command domain-authentication-mode
{ gca key-id { hmac-sha-1 | hmac-sha-224 | hmac-sha-256 | hmac-sha-384 | hmac-sha-512 }
| md5 | simple } { cipher cipher-string | plain plain-string }
[ ip | osi ]
Remarks
By default, no routing domain authentication is configured.
Configuring IS-IS 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 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.
•
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.
IMPORTANT:
IS-IS GR and IS-IS NSR are mutually exclusive. Do not configure them at the same time.
To configure GR on the GR restarter:
Step Command
1. Enter system view. system-view
2. Enable IS-IS and enter IS-IS view.
Remarks
N/A isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A
3. Enable IS-IS GR. graceful-restart
4. (Optional.) Suppress the SA bit during restart. graceful-restart suppress-sa
By default, the GR capability for IS-IS is disabled.
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.
149
Step
5. (Optional.)
Configure the T1 timer.
6. (Optional.)
Configure the T2 timer.
7. (Optional.)
Configure the T3 timer.
Command graceful-restart t1 seconds
count count graceful-restart t2 seconds
graceful-restart t3 seconds
Remarks
By default, the T1 timer is 3 seconds and can expire 10 times.
By default, the T2 timer is 60 seconds.
By default, the T2 timer is 300 seconds.
Configuring IS-IS NSR
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.
IMPORTANT:
IS-IS NSR and IS-IS GR are mutually exclusive. Do not configure them at the same time.
To configure IS-IS NSR:
Step Command
1. Enter system view. system-view
2. Enter IS-IS view.
3. Enable IS-IS NSR.
Remarks
N/A isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A non-stop-routing By default, IS-IS NSR is disabled.
Configuring BFD for IS-IS
BFD provides a single mechanism to quickly detect and monitor the connectivity of links between
OSPF neighbors, reducing network convergence time. For more information about BFD, see High
Availability Configuration Guide .
To configure BFD for IS-IS:
Step
1. Enter system view.
Command system-view
2. Enter interface view. interface interface-type interface-number
3. Enable IS-IS on an interface. isis enable [ process-id ]
Remarks
N/A
N/A
4. Enable BFD on an IS-IS interface. isis bfd enable
N/A
By default, an IS-IS interface is not enabled with
BFD.
150
Configuring IS-IS FRR
A link or router failure on a path can cause packet loss and routing loop. IS-IS FRR uses BFD to detect failures and enables fast rerouting to minimize the failover time.
Figure 39 Network diagram for IS-IS FRR
Backup nexthop: Router C
Router A Router B Nexthop: Router D Router E
In Figure 39 , after you enable 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 either enable IS-IS FRR to calculate a backup next hop automatically, or designate a backup next hop with a routing policy for routes matching specific criteria.
Configuration prerequisites
Before you configure IS-IS FRR, complete the following tasks:
•
Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable IS-IS.
Configuration guidelines
•
Do not use FRR and BFD at the same time. Otherwise, FRR might fail to take effect.
•
The automatic backup next hop calculation of FRR and that of TE are mutually exclusive.
Configuring IS-IS FRR to automatically calculate a backup next hop
Step
1. Enter system view.
2. Configure the source address of echo packets.
3. Enter IS-IS view.
4. Enable IS-IS FRR to automatically calculate a backup next hop.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of echo packets is not configured. isis [ process-id ] [ vpn-instance vpn-instance-name ]
N/A fast-reroute auto By default, IS-IS FRR is disabled.
151
Configuring IS-IS FRR using a routing policy
You can use the apply fast-reroute backup-interface command to specify a backup next hop in a routing policy for routes matching specific criteria. You can also perform this task to reference the routing policy for IS-IS FRR. For more information about the apply fast-reroute backup-interface
command and routing policy configurations, see " Configuring routing policies ."
To configure IS-IS FRR using a routing policy:
Step
1. Enter system view.
2. Configure the source address of echo packets.
3. Enter IS-IS view.
4. Enable IS-IS FRR using a routing policy.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source address of echo packets is not configured. isis [ process-id ] [ vpn-instance vpn-instance-name ] fast-reroute route-policy route-policy-name
N/A
By default, this feature is not enabled.
Configuring BFD for IS-IS FRR
By default, IS-IS FRR does not use BFD to detect primary link failures. To speed up IS-IS convergence, enable BFD single-hop echo detection for IS-IS FRR to detect primary link failures.
To configure BFD for IS-IS FRR:
Step
1. Enter system view.
2. Configure the source IP address of BFD echo packets.
Command system-view
bfd echo-source-ip ip-address
Remarks
N/A
By default, the source IP address of BFD echo packets is not configured.
For more information, see High
Availability Command Reference .
3. Enter interface view.
4. Enable BFD for IS-IS FRR.
interface interface-type interface-number isis primary-path-detect bfd echo
N/A
By default, BFD for IS-IS FRR is disabled.
Displaying and maintaining IS-IS
Execute display commands in any view and the reset command in user view.
Task
Display brief IS-IS backup configuration information.
Command display isis brief [ process-id ] [ standby slot slot-number ]
Display IS-IS GR log information.
Display the IS-IS GR status.
Display IS-IS backup interface information. display isis graceful-restart event-log slot slot-number display isis graceful-restart status [ level-1 | level-2 ]
[ process-id ] display isis interface [ interface-type interface-number ]
[ verbose ] [ process-id ] [ standby slot slot-number ]
152
Task Command
Display IS-IS backup LSDB information. display isis lsdb [ [ level-1 | level-2 ] | local | [ lsp-id lspid | lsp-name lspname ] | verbose ] * [ process-id ] [ standby slot slot-number ]
Display IS-IS mesh group configuration information. display isis mesh-group [ process-id ]
Display the host name to system ID mapping table.
Display IS-IS NSR log information. display isis name-table [ process-id ]
Display the IS-IS NSR status.
Display IS-IS backup neighbor information. display isis non-stop-routing event-log slot slot-number display isis non-stop-routing status [ process-id ] display isis peer [ statistics | verbose ] [ process-id ] [ standby slot slot-number ]
Display IS-IS redistributed route information.
Display IS-IS IPv4 routing information. display isis redistribute [ ipv4 [ ip-address mask-length ] ]
[ level-1 | level-2 ] [ process-id ] display isis route [ ipv4 [ ip-address mask-length ] ] [ [ level-1 | level-2 ] | verbose ] * [ process-id ]
Display IS-IS IPv4 topology information. display isis spf-tree [ ipv4 ] [ [ level-1 | level-2 ] | verbose ] *
[ process-id ]
Display IS-IS statistics.
Display OSI connection information.
Display OSI connection statistics.
Clear IS-IS process data structure information.
Clear IS-IS GR log information. display isis statistics [ level-1 | level-1-2 | level-2 ]
[ process-id ] display osi [ slot slot-number ] display osi statistics [ slot slot-number ] reset isis all [ process-id ] [ graceful-restart reset isis graceful-restart event-log slot
]
slot-number reset isis non-stop-routing event-log slot slot-number Clear IS-IS NSR log information.
Clear the data structure information of an IS-IS neighbor.
Clear OSI connection statistics. reset isis peer system-id reset osi statistics
[ process-id ]
IS-IS configuration examples
Basic IS-IS configuration example
Network requirements
As shown in Figure 40 , Switch A, Switch B, Switch C, and Switch D reside in an IS-IS AS.
Switch A and B are Level-1 switches, Switch D is a Level-2 switch, and Switch C is a Level-1-2 switch. Switch A, Switch B, and Switch C are in Area 10, and Switch D is in Area 20.
153
Figure 40 Network diagram
Vlan-int100
10.1.1.2/24
Switch A
L1
Vlan-int100
10.1.1.1/24
Vlan-int200
10.1.2.1/24
Vlan-int300
192.168.0.1/24
Vlan-int300
192.168.0.2/24
Switch C
L1/L2
Switch D
L2
Vlan-int100
172.16.1.1/16
Vlan-int200
10.1.2.2/24
Area 20
Switch B
L1
Area 10
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] is-level level-1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis enable 1
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis 1
[SwitchB-isis-1] is-level level-1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] isis enable 1
[SwitchB-Vlan-interface200] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] isis enable 1
[SwitchC-Vlan-interface100] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis enable 1
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 300
154
[SwitchC-Vlan-interface300] isis enable 1
[SwitchC-Vlan-interface300] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] isis 1
[SwitchD-isis-1] is-level level-2
[SwitchD-isis-1] network-entity 20.0000.0000.0004.00
[SwitchD-isis-1] quit
[SwitchD] interface vlan-interface 100
[SwitchD-Vlan-interface100] isis enable 1
[SwitchD-Vlan-interface100] quit
[SwitchD] interface vlan-interface 300
[SwitchD-Vlan-interface300] isis enable 1
[SwitchD-Vlan-interface300] quit
Verifying the configuration
# Display the IS-IS LSDB on each switch to verify the LSPs.
[SwitchA] display isis lsdb
Database information for IS-IS(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
[SwitchB] display isis lsdb
Database information for IS-IS(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
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
155
*-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload
[SwitchC] display isis lsdb
Database information for IS-IS(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
[SwitchD] display isis lsdb
Database information for IS-IS(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
# Display the IS-IS routing information on each switch.
[SwitchA] display isis route
156
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 Vlan100 Direct D/L/-
10.1.2.0/24 20 NULL Vlan100 10.1.1.1 R/-/-
192.168.0.0/24 20 NULL Vlan100 10.1.1.1 R/-/-
0.0.0.0/0 10 NULL Vlan100 10.1.1.1 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[SwitchC] display isis route
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
192.168.0.0/24 10 NULL Vlan300 Direct D/L/-
10.1.1.0/24 10 NULL Vlan100 Direct D/L/-
10.1.2.0/24 10 NULL Vlan200 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
-------------------------------------------------------------------------------
192.168.0.0/24 10 NULL Vlan300 Direct D/L/-
10.1.1.0/24 10 NULL Vlan100 Direct D/L/-
10.1.2.0/24 10 NULL Vlan200 Direct D/L/-
172.16.0.0/16 20 NULL Vlan300 192.168.0.2 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[SwitchD] display isis route
Route information for IS-IS(1)
------------------------------
Level-2 IPv4 Forwarding Table
-----------------------------
157
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
192.168.0.0/24 10 NULL Vlan300 Direct D/L/-
10.1.1.0/24 20 NULL Vlan300 192.168.0.1 R/-/-
10.1.2.0/24 20 NULL Vlan300 192.168.0.1 R/-/-
172.16.0.0/16 10 NULL Vlan100 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 switches contains a default route with the next hop as the Level-1-2 switch. The routing table of Level-2 switch contains both routing information of
Level-1 and Level-2.
DIS election configuration example
Network requirements
As shown in Figure 41 , Switches A, B, C, and D reside in IS-IS area 10 on a broadcast network
(Ethernet). Switch A and Switch B are Level-1-2 switches, Switch C is a Level-1 switch, and Switch D is a Level-2 switch.
Change the DIS priority of Switch A to make it elected as the Level-1-2 DIS router.
Figure 41 Network diagram
Switch A
L1/L2
Switch B
L1/L2
Vlan-int100
10.1.1.1/24
Vlan-int100
10.1.1.2/24
Vlan-int100
10.1.1.3/24
Vlan-int100
10.1.1.4/24
Switch C
L1
Configuration procedure
Switch D
L2
1. Configure IP addresses for interfaces. (Details not shown.)
2. Enable IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis enable 1
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
158
[SwitchB] isis 1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] isis enable 1
[SwitchB-Vlan-interface100] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] is-level level-1
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] isis enable 1
[SwitchC-Vlan-interface100] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] isis 1
[SwitchD-isis-1] network-entity 10.0000.0000.0004.00
[SwitchD-isis-1] is-level level-2
[SwitchD-isis-1] quit
[SwitchD] interface vlan-interface 100
[SwitchD-Vlan-interface100] isis enable 1
[SwitchD-Vlan-interface100] quit
# Display information about IS-IS neighbors on Switch A.
[SwitchA] display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0003.01
State: Up HoldTime: 21s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0003
Interface: Vlan-interface100 Circuit Id: 0000.0000.0003.01
State: Up HoldTime: 27s Type: L1 PRI: 64
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0004.01
State: Up HoldTime: 28s Type: L2(L1L2) PRI: 64
System Id: 0000.0000.0004
Interface: Vlan-interface100 Circuit Id: 0000.0000.0004.01
State: Up HoldTime: 30s Type: L2 PRI: 64
# Display information about IS-IS interfaces on Switch A.
[SwitchA] display isis interface
Interface information for IS-IS(1)
159
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 No/No
# Display information about IS-IS interfaces on Switch C.
[SwitchC] display isis interface
Interface information for IS-IS(1)
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 Yes/No
# Display information about IS-IS interfaces on Switch D.
[SwitchD] display isis interface
Interface information for IS-IS(1)
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 No/Yes
The output shows that when the default DIS priority is used, Switch C is the DIS for Level-1, and
Switch 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 Switch A.
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis dis-priority 100
[SwitchA-Vlan-interface100] quit
# Display IS-IS neighbors on Switch A.
[SwitchA] display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 21s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0003
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 27s Type: L1 PRI: 64
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 28s Type: L2(L1L2) PRI: 64
160
System Id: 0000.0000.0004
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 30s Type: L2 PRI: 64
# Display information about IS-IS interfaces on Switch A.
[SwitchA] display isis interface
Interface information for IS-IS(1)
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 Yes/Yes
The output shows that after the DIS priority configuration, Switch A becomes the DIS for
Level-1-2, and the pseudonode is 0000.0000.0001.01.
# Display information about IS-IS neighbors and interfaces on Switch C.
[SwitchC] display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 25s Type: L1 PRI: 64
System Id: 0000.0000.0001
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 7s Type: L1 PRI: 100
[SwitchC] display isis interface
Interface information for IS-IS(1)
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 No/No
# Display information about IS-IS neighbors and interfaces on Switch D.
[SwitchD] display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0001
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 9s Type: L2 PRI: 100
System Id: 0000.0000.0002
Interface: Vlan-interface100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 28s Type: L2 PRI: 64
[SwitchD] display isis interface
161
Interface information for IS-IS(1)
----------------------------------
Interface: Vlan-interface100
Id IPv4.State IPv6.State MTU Type DIS
001 Up Down 1497 L1/L2 No/No
IS-IS route redistribution configuration example
Network requirements
As shown in Figure 42 , Switch A, Switch B, Switch C, and Switch D reside in the same AS. They use
IS-IS to interconnect. Switch A and Switch B are Level-1 routers, Switch D is a Level-2 router, and
Switch C is a Level-1-2 router.
Redistribute RIP routes into IS-IS on Switch D.
Figure 42 Network diagram
Switch A
L1
Vlan-int100
10.1.1.2/24
Vlan-int100
10.1.1.1/24
Vlan-int200
10.1.2.1/24
Vlan-int500
10.1.5.1/24
Vlan-int300
192.168.0.1/24
Switch C
L1/L2
Vlan-int300
192.168.0.2/24
RIP
Switch D
L2
Vlan-int400
10.1.4.1/24
Vlan-int400
10.1.4.2/24
Switch E
Vlan-int600
10.1.6.1/24
Vlan-int200
10.1.2.2/24 Area 20
Switch B
L1
Area 10
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] is-level level-1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis enable 1
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis 1
[SwitchB-isis-1] is-level level-1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 200
162
[SwitchB-Vlan-interface200] isis enable 1
[SwitchB-Vlan-interface200] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis enable 1
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] isis enable 1
[SwitchC-Vlan-interface100] quit
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] isis enable 1
[SwitchC-Vlan-interface300] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] isis 1
[SwitchD-isis-1] is-level level-2
[SwitchD-isis-1] network-entity 20.0000.0000.0004.00
[SwitchD-isis-1] quit
[SwitchD] interface interface vlan-interface 300
[SwitchD-Vlan-interface300] isis enable 1
[SwitchD-Vlan-interface300] quit
# Display IS-IS routing information on each switch.
[SwitchA] 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 VLAN100 Direct D/L/-
10.1.2.0/24 20 NULL VLAN100 10.1.1.1 R/-/-
192.168.0.0/24 20 NULL VLAN100 10.1.1.1 R/-/-
0.0.0.0/0 10 NULL VLAN100 10.1.1.1 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[SwitchC] display isis route
Route information for IS-IS(1)
------------------------------
Level-1 IPv4 Forwarding Table
163
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
10.1.1.0/24 10 NULL VLAN100 Direct D/L/-
10.1.2.0/24 10 NULL VLAN200 Direct D/L/-
192.168.0.0/24 10 NULL VLAN300 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 VLAN100 Direct D/L/-
10.1.2.0/24 10 NULL VLAN200 Direct D/L/-
192.168.0.0/24 10 NULL VLAN300 Direct D/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
[SwitchD] display isis route
Route information for IS-IS(1)
------------------------------
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
192.168.0.0/24 10 NULL VLAN300 Direct D/L/-
10.1.1.0/24 20 NULL VLAN300 192.168.0.1 R/-/-
10.1.2.0/24 20 NULL VLAN300 192.168.0.1 R/-/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
3. Run RIPv2 between Switch D and Switch E, and configure IS-IS to redistribute RIP routes on
Switch D:
# Configure RIPv2 on Switch D.
[SwitchD] rip 1
[SwitchD-rip-1] network 10.0.0.0
[SwitchD-rip-1] version 2
[SwitchD-rip-1] undo summary
# Configure RIPv2 on Switch E.
[SwitchE] rip 1
[SwitchE-rip-1] network 10.0.0.0
[SwitchE-rip-1] version 2
[SwitchE-rip-1] undo summary
# Configure IS-IS to redistribute RIP routes on Switch D.
164
[SwitchD-rip-1] quit
[SwitchD] isis 1
[SwitchD–isis-1] import-route rip level-2
# Display IS-IS routing information on Switch C.
[SwitchC] 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 VLAN100 Direct D/L/-
10.1.2.0/24 10 NULL VLAN200 Direct D/L/-
192.168.0.0/24 10 NULL VLAN300 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 VLAN100 Direct D/L/-
10.1.2.0/24 10 NULL VLAN200 Direct D/L/-
192.168.0.0/24 10 NULL VLAN300 Direct D/L/-
10.1.4.0/24 10 NULL VLAN300 192.168.0.2 R/L/-
10.1.5.0/24 20 NULL VLAN300 192.168.0.2 R/L/-
10.1.6.0/24 20 NULL VLAN300 192.168.0.2 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
IS-IS authentication configuration example
Network requirements
As shown in Figure 43 , Switch A, Switch B, Switch C, and Switch D reside in the same IS-IS routing
domain. Run IS-IS among them.
Switch A, Switch B, and Switch C belong to Area 10, and Switch 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 Switch C and Switch D to prevent untrusted routes from entering the routing domain.
165
Figure 43 Network diagram
Vlan-int100
10.1.1.2/24
Switch A
L1
Vlan-int100
10.1.1.1/24
Vlan-int300
10.1.3.1/24
Vlan-int200
10.1.2.1/24 Switch C
L1/L2
Vlan-int200
10.1.2.2/24
Vlan-int300
10.1.3.2/24
Switch D
L2
Area 20
Switch B
L1
Area 10
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis enable 1
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis 1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] isis enable 1
[SwitchB-Vlan-interface200] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis enable 1
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] isis enable 1
[SwitchC-Vlan-interface300] quit
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] isis enable 1
[SwitchC-Vlan-interface300] quit
166
# Configure Switch D.
<SwitchD> system-view
[SwitchD] isis 1
[SwitchD-isis-1] network-entity 20.0000.0000.0001.00
[SwitchD-isis-1] quit
[SwitchD] interface vlan-interface 300
[SwitchD-Vlan-interface300] isis enable 1
[SwitchD-Vlan-interface300] quit
3. Configure neighbor relationship authentication between neighbors:
# Configure the authentication mode as MD5 and set the plaintext password to eRq on
VLAN-interface 100 of Switch A and on VLAN-interface 100 of Switch C.
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis authentication-mode md5 plain eRg
[SwitchA-Vlan-interface100] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] isis authentication-mode md5 plain eRg
[SwitchC-Vlan-interface100] quit
# Configure the authentication mode as MD5 and set the plaintext password to t5Hr on
VLAN-interface 200 of Switch B and on VLAN-interface 200 of Switch C.
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] isis authentication-mode md5 plain t5Hr
[SwitchB-Vlan-interface200] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis authentication-mode md5 plain t5Hr
[SwitchC-Vlan-interface200] quit
# Configure the authentication mode as MD5 and set the plaintext password to hSec on
VLAN-interface 300 of Switch D and on VLAN-interface 300 of Switch C.
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] isis authentication-mode md5 plain hSec
[SwitchC-Vlan-interface300] quit
[SwitchD] interface vlan-interface 300
[SwitchD-Vlan-interface300] isis authentication-mode md5 plain hSec
[SwitchD-Vlan-interface300] quit
4. Configure the area authentication mode as MD5 and set the plaintext password to 10Sec on
Switch A, Switch B, and Switch C.
[SwitchA] isis 1
[SwitchA-isis-1] area-authentication-mode md5 plain 10Sec
[SwitchA-isis-1] quit
[SwitchB] isis 1
[SwitchB-isis-1] area-authentication-mode md5 plain 10Sec
[SwitchB-isis-1] quit
[SwitchC] isis 1
[SwitchC-isis-1] area-authentication-mode md5 plain 10Sec
[SwitchC-isis-1] quit
5. Configure routing domain authentication mode as MD5 and set the plaintext password to
1020Sec on Switch C and Switch D.
[SwitchC] isis 1
[SwitchC-isis-1] domain-authentication-mode md5 plain 1020Sec
[SwitchC-isis-1] quit
167
[SwitchD] isis 1
[SwitchD-isis-1] domain-authentication-mode md5 plain 1020Sec
IS-IS GR configuration example
Network requirements
As shown in Figure 44 , Switch A, Switch B, and Switch C belong to the same IS-IS routing domain.
Figure 44 Network diagram
GR restarter
Switch A
Vlan-int100
10.0.0.1/24
Vlan-int100
10.0.0.2/24
Switch B
Vlan-int100
10.0.0.3/24
Switch C
GR helper GR helper
Configuration procedure
1. Configure IP addresses and subnet masks for interfaces. (Details not shown.)
2. Configure IS-IS on the switches to make sure Switch A, Switch B, and Switch 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 Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] graceful-restart
[SwitchA-isis-1] return
Verifying the configuration
After Switch A establishes adjacencies with Switch B and Switch C, they begin to exchange routing information.
# Restart the IS-IS process on Switch A.
<SwitchA> reset isis all 1 graceful-restart
Reset IS-IS process? [Y/N]:y
Switch A enters the restart state and sends connection requests to its neighbors through the GR mechanism to synchronize the LSDB.
# Check the GR status of IS-IS on Switch A.
<SwitchA> 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
168
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
Level-2 restart information
---------------------------
Total number of interfaces: 1
Number of waiting LSPs: 0
IS-IS NSR configuration example
Network requirements
As shown in Figure 45 , Switch S, Switch A, and Switch B belong to the same IS-IS routing domain.
•
Run IS-IS on all the switches to interconnect them with each other.
•
Enable IS-IS NSR on Switch S to ensure forwarding continuity between Switch A and Switch B when an active/standby switchover occurs on Switch S.
Figure 45 Network diagram
Loop 0
22.22.22.22/32
Switch A
Vlan-int100
12.12.12.1/24
Vlan-int100
12.12.12.2/24
Switch S
Vlan-int200
14.14.14.1/24
Vlan-int200
14.14.14.2/24
Switch B
Loop 0
44.44.44.44/32
Configuration procedure
1. Configure the IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
2. Configure IS-IS on the switches to make sure Switch S, Switch A, and Switch 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 Switch S.
<SwitchS> system-view
[SwitchS] isis 1
[SwitchS-isis-1] non-stop-routing
[SwitchS-isis-1] return
Verifying the configuration
# Reoptimize process placement on Switch S to trigger an active/standby switchover.
<SwitchS> system-view
[SwitchS] placement reoptimize
Predicted changes to the placement
Program Current location New location
--------------------------------------------------------------------- syslog 0/0 0/0 diagusageratio 0/0 0/0 l3vpn 0/0 0/0 fc 0/0 0/0 dns 0/0 0/0 lauth 0/0 0/0
169
aaa 0/0 0/0 lsm 0/0 0/0 rm 0/0 0/0 rm6 0/0 0/0 track 0/0 0/0 ip6addr 0/0 0/0 ipaddr 0/0 0/0 rpm 0/0 0/0 trange 0/0 0/0 tunnel 0/0 0/0 lagg 0/0 0/0 bfd 0/0 0/0 acl 0/0 0/0 slsp 0/0 0/0 usr6 0/0 0/0 usr 0/0 0/0 qos 0/0 0/0 fczone 0/0 0/0 ethbase 0/0 0/0 ipcim 0/0 0/0 ip6base 0/0 0/0 ipbase 0/0 0/0 eth 0/0 0/0 eviisis 0/0 0/0 ifnet NA NA 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
# Display IS-IS neighbor information on Switch A.
<SwitchA> display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0001
Interface: vlan100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 25s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0001
Interface: vlan100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 27s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Switch A.
<SwitchA> display isis route
Route information for IS-IS(1)
-----------------------------
170
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL vlan100 Direct D/L/-
22.22.22.22/32 10 NULL Loop0 Direct D/-/-
14.14.14.0/32 10 NULL vlan100 12.12.12.2 R/L/-
44.44.44.44/32 10 NULL vlan100 12.12.12.2 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
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL vlan100 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 Switch B.
<SwitchB> display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0001
Interface: vlan200 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 25s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0001
Interface: vlan200 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 27s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Switch B.
<SwitchB> display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
171
14.14.14.0/24 10 NULL vlan200 Direct D/L/-
44.44.44.44/32 10 NULL Loop0 Direct D/-/-
12.12.12.0/32 10 NULL vlan200 14.14.14.4 R/L/-
22.22.22.22/32 10 NULL vlan200 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
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
14.14.14.0/24 10 NULL vlan200 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 Switch A and Switch B have not changed during the active/standby switchover on Switch S. The neighbors are unaware of the switchover.
BFD for IS-IS configuration example
Network requirements
•
As shown in Figure 46 , run IS-IS on Switch A, Switch B and Switch C so that can reach each
other at the network layer.
•
After the link over which Switch A and Switch B communicate through the Layer-2 switch fails,
BFD can quickly detect the failure and notify IS-IS of the failure. Switch A and Switch B then communicate through Switch C.
Figure 46 Network diagram
Loop0
Switch A
Vlan-int10
Vlan-int11
BFD
L2 Switch
Vlan-int10
Switch B
Vlan-int13
Loop0
Device
Switch A
Switch C
Area 0
Vlan-int11
Switch C
Vlan-int13
Interface
Vlan-int10
Vlan-int11
Loop0
Vlan-int11
Vlan-int13
IP address
10.1.0.102/24
11.1.1.1/24
121.1.1.1/32
11.1.1.2/24
13.1.1.2/24
Device
Switch B
172
Interface
Vlan-int10
Vlan-int13
Loop0
IP address
10.1.0.100/24
13.1.1.1/24
120.1.1.1/32
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure basic IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] quit
[SwitchA] interface loopback 0
[SwitchA-LoopBack0] isis enable
[SwitchA-LoopBack0] quit
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] isis enable
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 11
[SwitchA-Vlan-interface11] isis enable
[SwitchA-Vlan-interface11] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface loopback 0
[SwitchB-LoopBack0] isis enable
[SwitchB-LoopBack0] quit
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] isis enable
[SwitchB-Vlan-interface10] quit
[SwitchB] interface vlan-interface 13
[SwitchB-Vlan-interface13] isis enable
[SwitchB-Vlan-interface13] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 11
[SwitchC-Vlan-interface11] isis enable
[SwitchC-Vlan-interface11] quit
[SwitchC] interface vlan-interface 13
[SwitchC-Vlan-interface13] isis enable
[SwitchC-Vlan-interface13] quit
3. Configure BFD functions:
# Enable BFD and configure BFD parameters on Switch A.
[SwitchA] bfd session init-mode passive
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] isis bfd enable
173
[SwitchA-Vlan-interface10] bfd min-receive-interval 500
[SwitchA-Vlan-interface10] bfd min-transmit-interval 500
[SwitchA-Vlan-interface10] bfd detect-multiplier 7
# Enable BFD and configure BFD parameters on Switch B.
[SwitchB] bfd session init-mode active
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] isis bfd enable
[SwitchB-Vlan-interface10] bfd min-receive-interval 500
[SwitchB-Vlan-interface10] bfd min-transmit-interval 500
[SwitchB-Vlan-interface10] bfd detect-multiplier 8
[SwitchB-Vlan-interface10] return
Verifying the configuration
# Display the BFD session information on Switch A.
<SwitchA> 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 Vlan10
# Display routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 verbose
Summary Count : 1
Destination: 120.1.1.0/24
Protocol: ISIS Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
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
Tunnel ID: Invalid Interface: Vlan-interface10
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A and Switch B communicate through VLAN-interface 10. The link over VLAN-interface 10 fails.
# Display routes destined for 120.1.1.0/24 on Switch A.
<SwitchA> display ip routing-table 120.1.1.0 verbose
Summary Count : 1
174
Destination: 120.1.1.0/24
Protocol: ISIS Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 20 Preference: 10
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
Tunnel ID: Invalid Interface: Vlan-interface11
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch A and Switch B communicate through VLAN-interface 11.
IS-IS FRR configuration example
Network requirements
As shown in Figure 47 , Switch A, Switch B, and Switch C belong to the same IS-IS routing domain.
Configure IS-IS FRR so that when the Link A fails, traffic can be switched to Link B immediately.
Figure 47 Network diagram
Switch C
Vlan
-int
100
Link B
Vlan
-int
101
Vlan
-int
100
Link A
Vlan
-int
101
Loop0 Loop0
Switch A
Vlan-int200 Vlan-int200
Switch B
Device
Switch A
Switch C
Interface IP address
Vlan-int100 12.12.12.1/24
Vlan-int200 13.13.13.1/24
Loop0 1.1.1.1/32
Vlan-int100 12.12.12.2/24
Vlan-int101 24.24.24.2/24
Device
Switch B
Interface IP address
Vlan-int101 24.24.24.4/24
Vlan-int200 13.13.13.2/24
Loop0 4.4.4.4/32
Configuration procedure
1. Configure IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
2. Configure IS-IS on the switches to make sure Switch A, Switch B, and Switch C can communicate with each other at Layer 3. (Details not shown.)
3. Configure IS-IS FRR:
Enable IS-IS FRR to automatically calculate a backup next hop, or designate a backup next hop by using a referenced routing policy.
ï‚¡
(Method 1.) Enable IS-IS FRR to automatically calculate a backup next hop:
# Configure Switch A.
<SwitchA> system-view
175
ï‚¡
[SwitchA] bfd echo-source-ip 2.2.2.2
[SwitchA] isis 1
[SwitchA-isis-1] fast-reroute auto
[SwitchA-isis-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 3.3.3.3
[SwitchB] isis 1
[SwitchB-isis-1] fast-reroute auto
[SwitchB-isis-1] quit
(Method 2.) Enable IS-IS FRR to designate a backup next hop by using a referenced routing policy:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bfd echo-source-ip 2.2.2.2
[SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32
[SwitchA] route-policy frr permit node 10
[SwitchA-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchA-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
100 backup-nexthop 12.12.12.2
[SwitchA-route-policy-frr-10] quit
[SwitchA] isis 1
[SwitchA-isis-1] fast-reroute route-policy frr
[SwitchA-isis-1] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bfd echo-source-ip 3.3.3.3
[SwitchB] ip prefix-list abc index 10 permit 1.1.1.1 32
[SwitchB] route-policy frr permit node 10
[SwitchB-route-policy-frr-10] if-match ip address prefix-list abc
[SwitchB-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface
101 backup-nexthop 24.24.24.2
[SwitchB-route-policy-frr-10] quit
[SwitchB] isis 1
[SwitchB-isis-1] fast-reroute route-policy frr
[SwitchB-isis-1] quit
Verifying the configuration
# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.
[SwitchA] display ip routing-table 4.4.4.4 verbose
Summary Count : 1
Destination: 4.4.4.4/32
Protocol: ISIS Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
176
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface100
# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.
[SwitchB] display ip routing-table 1.1.1.1 verbose
Summary Count : 1
Destination: 1.1.1.1/32
Protocol: ISIS Process ID: 1
SubProtID: 0x1 Age: 04h20m37s
Cost: 10 Preference: 10
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
Tunnel ID: Invalid Interface: Vlan-interface200
BkTunnel ID: Invalid BkInterface: Vlan-interface101
177
Configuring 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 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.
BGP peers include the following types:
•
IBGP peers —Reside in the same AS as the local router.
•
EBGP peers —Reside in different ASs from 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 with 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 of a specified address family from a peer.
•
Notification —BGP sends a Notification message upon detecting an error and immediately closes the connection.
BGP path attributes
BGP uses the following path attributes in update messages for route filtering and selection:
•
ORIGIN
178
The ORIGIN attribute specifies the origin of BGP routes. This attribute has the following types:
ï‚¡
IGP —Has the highest priority. Routes generated in the local AS have the IGP attribute.
ï‚¡
EGP —Has the second highest priority. Routes obtained through EGP have the EGP attribute.
ï‚¡ 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:
ï‚¡
ï‚¡
AS_SEQUENCE
—Arranges AS numbers in sequence. As shown in Figure 48 , the number
of the AS closest to the receiver's AS is leftmost.
AS_SET —Arranges AS numbers randomly.
Figure 48 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:
ï‚¡
Avoid routing loops —A BGP router does not receive routes containing the local AS number to avoid routing loops.
ï‚¡
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 48 , 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 ."
ï‚¡
Filter routes —By using an AS path list, you can filter routes based on AS numbers contained in the AS_PATH attribute. For more information about AS path list, see
" Configuring routing policies ."
•
NEXT_HOP
The NEXT_HOP attribute may not be the IP address of a directly-connected router. Its value is determined as follows:
ï‚¡ 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.
179
ï‚¡
ï‚¡
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
Figure 49 NEXT_HOP attribute
D = 8.0.0.0
Next_hop = 1.1.1.1
AS 100
AS 200
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, it considers the route with the smallest MED value as the optimal route. As shown in
Figure 50 , traffic from AS 10 to AS 20 travels through Router B that is selected according to
MED.
Figure 50 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
AS 10
EBGP IBGP
3.1.1.1
MED = 100
Router C
AS 20
180
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 considers the route with the highest LOCAL_PREF value as the optimal route. As shown in
Figure 51 , traffic from AS 20 to AS 10 travels through Router C that is selected according to
LOCAL_PREF.
Figure 51 LOCAL_PREF attribute
Local_pref = 100
Router B
8.0.0.0
2.1.1.1
Router A
3.1.1.1
EBGP
EBGP
IBGP
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
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:
ï‚¡
INTERNET —By default, all routes belong to the Internet community. Routes with this attribute can be advertised to all BGP peers.
ï‚¡
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 ."
ï‚¡
ï‚¡
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.
181
•
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:
ï‚¡
Provides more attribute values by extending the attribute length to eight bytes.
ï‚¡ Allows for using different types of extended community attributes in different scenarios to enhance route filtering and control and simplify configuration and management.
Currently, the device supports the Route-Target attribute for VPN and Site of Origin (SoO) attribute. For more information, see MPLS Configuration Guide .
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 shortest AS_PATH.
5. The IGP, EGP, or INCOMPLETE route in turn.
6. The route with the lowest MED value.
7. The route learned from EBGP, confederation EBGP, confederation IBGP, or IBGP in turn.
8. The route with the smallest next hop metric.
9. The route with the shortest CLUSTER_LIST.
10. The route with the smallest ORIGINATOR_ID.
11. The route advertised by the router with the smallest router ID.
12. 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 follow 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.
•
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 with 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 implements load balancing through route recursion and route selection.
182
•
BGP load balancing through route recursion.
The next hop of a BGP route may not be directly connected. One of the reasons is next hops in routing information exchanged between IBGP peers are 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.
The system supports BGP load balancing based on 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 by the system rather than configured by using commands.
•
BGP load balancing through route selection.
IGP routing protocols, such as RIP and OSPF, compute the metrics of routes, and implement load balancing over the routes with the same metric and to the same destination. The route selection criterion is metric.
BGP has no route computation algorithm, so it cannot perform load balancing according to the metrics of routes. BGP implements load balancing over the routes that meet the following requirements:
ï‚¡ The routes have the same AS_PATH, ORIGIN, LOCAL_PREF, and MED attributes. (When the as-path-neglect keyword is specified in the balance command, BGP implements load balancing over routes with different AS_PATH attributes. Use the as-path-neglect keyword according to your network, and make sure a routing loop does not occur.)
ï‚¡ The routes are all reflected or not reflected by the route reflector.
BGP does not use the route selection rules described in " BGP route selection " for load
balancing.
Figure 52 Network diagram
Router A Router D
Router C
AS 200 AS 100
9.0.0.0/24
Router B Router E
As shown in Figure 52 , Router A and Router B are IBGP peers of Router C. 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 following conditions exist:
ï‚¡
Load balancing with a maximum number of two routes is configured on Router C.
ï‚¡ The two routes have the same AS_PATH, ORIGIN, LOCAL_PREF, and MED.
After that, Router C forwards to Router A and Router B a single route that has NEXT_HOP changed to Router C and other attributes changed to those of the optimal route.
NOTE:
BGP load balancing is applicable between EBGP peers, between IBGP peers, and between confederations.
183
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 frapping (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.
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 53 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
184
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.
must establish BGP sessions to the route reflector and other non-clients.
Figure 54 Network diagram for a route reflector
IBGP
Route reflector
IBGP
Non-client
Cluster
Client
IBGP
IBGP
IBGP
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 55 . The configured route reflectors must have
the same Cluster_ID to avoid routing loops.
Figure 55 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.
185
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 Figure 56 ,
intra-confederation EBGP connections are established between sub-ASs in AS 200.
Figure 56 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. It considers the confederation as one AS, and the confederation ID as 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
BGP-4 carries only IPv4 unicast routing information. IETF extended BGP-4 by introducing
Multiprotocol Extensions for BGP-4 (MP-BGP). MP-BGP can carry routing information for multiple address families, including IPv4 multicast, IPv6 unicast, IPv6 multicast, and VPNv4.
MP-BGP is backward compatible with BGP.
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.
•
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.
186
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.
The current MP-BGP implementation supports multiple protocol extensions, including VPN, IPv6, and multicast. For more information about VPN, see MPLS Configuration Guide .
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.
BGP configuration views
BGP uses different views to manage routing information for different address families and different
VPN instances. 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 14 describes different BGP configuration views.
Table 14 BGP configuration views
View names
BGP view
BGP IPv4 unicast address family view
BGP IPv6 unicast address family view
BGP VPNv4 address family view
BGP VPNv6 address family view
Ways to enter the views
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp]
Remarks
Configurations in this view apply to all address families of the public network and all VPN instances
(such as confederation, GR, and logging configurations), or apply to all address families of the public network.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family ipv4 unicast
[Sysname-bgp-ipv4]
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family ipv6 unicast
[Sysname-bgp-ipv6]
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family vpnv4
[Sysname-bgp-vpnv4]
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family vpnv6
[Sysname-bgp-vpnv6]
Configurations in this view apply to
IPv4 unicast routes and peers on the public network.
Configurations in this view apply to
IPv6 unicast routes and peers on the public network.
Configurations in this view apply to
VPNv4 routes and peers.
For more information about BGP
VPNv4 address family view, see
MPLS Configuration Guide .
Configurations in this view apply to
VPNv6 routes and peers.
For more information about BGP
VPNv6 address family view, see
MPLS Configuration Guide .
187
View names
BGP L2VPN address family view
BGP-VPN instance view
BGP-VPN IPv4 unicast address family view
BGP-VPN IPv6 unicast address family view
BGP-VPN VPNv4 address family view
Ways to enter the views
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family l2vpn
[Sysname-bgp-l2vpn]
Remarks
Configurations in this view apply to
L2VPN information and L2VPN peers.
For more information about BGP l2VPN address family view, see
MPLS Configuration Guide .
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
[Sysname-bgp-vpn1]
Configurations in this view apply to all address families in the specified
VPN instance.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
Configurations in this view apply to
IPv4 unicast routes and peers in the specified VPN instance.
[Sysname-bgp-vpn1] address-family ipv4 unicast
[Sysname-bgp-ipv4-vpn1]
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
Configurations in this view apply to
IPv6 unicast routes and peers in the specified VPN instance.
[Sysname-bgp-vpn1] address-family ipv6 unicast
[Sysname-bgp-ipv6-vpn1]
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
Configurations in this view apply to
VPNv4 routes and peers in the specified VPN instance.
[Sysname-bgp-vpn1] address-family vpnv4
[Sysname-bgp-vpnv4-vpn1]
For more information about
BGP-VPN VPNv4 address family view, see MPLS Configuration
Guide .
Protocols and standards
•
RFC 1700, ASSIGNED NUMBERS
•
RFC 1771, A Border Gateway Protocol 4 (BGP-4)
•
RFC 1997, BGP Communities Attribute
•
RFC 2439, BGP Route Flap Damping
•
RFC 2796, BGP Route Reflection
•
RFC 2858, Multiprotocol Extensions for BGP-4
•
RFC 2918, Route Refresh Capability for BGP-4
•
RFC 3065, Autonomous System Confederations for BGP
•
RFC 3392, Capabilities Advertisement with BGP-4
•
RFC 4271, A Border Gateway Protocol 4 (BGP-4)
•
RFC 4360, BGP Extended Communities Attribute
•
RFC 4724, Graceful Restart Mechanism for BGP
•
RFC 4760, Multiprotocol Extensions for BGP-4
188
•
RFC 5082, The Generalized TTL Security Mechanism (GTSM)
BGP configuration task list
In a basic BGP network, you only need to perform the following configurations:
•
Enable BGP.
•
Configure BGP peers or peer groups. If you configure a BGP setting at both the peer group and the peer level, the most recent configuration takes effect on the peer.
•
Control BGP route generation.
To control BGP route distribution and path selection, you must perform additional configuration tasks.
To configure BGP, perform the following tasks (IPv4):
Remarks Tasks at a glance
•
•
(Required.) Perform one of the following tasks:
ï‚¡
ï‚¡
ï‚¡
•
(Optional.) Specifying the source address of TCP connections
Generating BGP routes (perform at least one of the following tasks):
•
•
(Optional.) Controlling route distribution and reception :
•
Configuring BGP route summarization
•
Advertising optimal routes in the IP routing table
•
Advertising a default route to a peer or peer group
•
Limiting routes received from a peer or peer group
•
Configuring BGP route filtering policies
•
Configuring BGP route dampening
(Optional.) Controlling BGP path selection :
•
Specifying a preferred value for routes received
•
Configuring preferences for BGP routes
•
Configuring the default local preference
•
•
Configuring the NEXT_HOP attribute
•
Configuring the AS_PATH attribute
As a best practice, configure BGP peer groups on large scale
BGP networks for easy configuration and maintenance.
N/A
N/A
N/A
189
Tasks at a glance
(Optional.) Tuning and optimizing BGP networks :
•
Configuring the keepalive interval and hold time
•
Configuring the interval for sending updates for the same route
•
Enabling BGP to establish an EBGP session over multiple hops
Enabling immediate re-establishment of direct EBGP connections upon link failure
•
Enabling 4-byte AS number suppression
•
Enabling MD5 authentication for BGP peers
•
Configuring BGP load balancing
•
Configuring IPsec for IPv6 BGP
•
Disabling BGP to establish a session to a peer or peer group
•
•
•
Protecting an EBGP peer when memory usage reaches level 2 threshold
(Optional.) Configuring a large-scale BGP network :
•
•
Configuring BGP route reflection
•
Ignoring the ORIGINATOR_ID attribute
•
Configuring a BGP confederation
(Optional.) Configuring BGP GR
(Optional.) Configuring BGP NSR
(Optional.) Enabling SNMP notifications for BGP
(Optional.) Enabling logging of session state changes
(Optional.) Enabling logging for BGP route flapping
(Optional.) Configuring BFD for BGP
(Optional.) Configuring BGP FRR
To configure BGP, perform the following tasks (IPv6):
Tasks at a glance
•
•
(Required.) Perform one of the following tasks:
ï‚¡
ï‚¡
ï‚¡
•
(Optional.) Specifying the source address of TCP connections
Generating BGP routes (perform at least one of the following tasks):
•
•
Remarks
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Remarks
As a best practice, configure BGP peer groups on large scale
BGP networks for easy configuration and maintenance.
N/A
190
Tasks at a glance
(Optional.) Controlling route distribution and reception :
•
Configuring BGP route summarization
•
Advertising optimal routes in the IP routing table
•
Advertising a default route to a peer or peer group
•
Limiting routes received from a peer or peer group
•
Configuring BGP route filtering policies
•
Configuring BGP update sending delay
•
Configuring BGP route dampening
(Optional.) Controlling BGP path selection :
•
Specifying a preferred value for routes received
•
Configuring preferences for BGP routes
•
Configuring the default local preference
•
•
Configuring the NEXT_HOP attribute
•
Configuring the AS_PATH attribute
(Optional.) Tuning and optimizing BGP networks :
•
Configuring the keepalive interval and hold time
•
Configuring the interval for sending updates for the same route
•
Enabling BGP to establish an EBGP session over multiple hops
Enabling immediate re-establishment of direct EBGP connections upon link failure
•
Enabling 4-byte AS number suppression
•
Enabling MD5 authentication for BGP peers
•
Configuring BGP load balancing
•
Configuring IPsec for IPv6 BGP
•
•
•
Protecting an EBGP peer when memory usage reaches level 2 threshold
(Optional.) Configuring a large-scale BGP network :
•
•
Configuring BGP route reflection
•
Ignoring the ORIGINATOR_ID attribute
•
Configuring a BGP confederation
(Optional.) Configuring BGP GR
(Optional.) Enabling SNMP notifications for BGP
(Optional.) Enabling logging of session state changes
(Optional.) Enabling logging for BGP route flapping
(Optional.) Configuring BFD for BGP
(Optional.) Configuring BGP FRR
Remarks
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Configuring basic BGP
This section describes the basic settings required for a BGP network to run.
191
Enabling BGP
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 view the IP address of a local loopback interface as the router ID.
•
If no router ID is specified in BGP view, the global router ID is used.
•
To modify a non-zero router ID of BGP, use the router-id command in BGP view, rather than the router id command in system view.
•
If you specify a router ID in BGP 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 view.
To enable BGP:
Step
1. Enter system view.
Command system-view
2. Configure a global router ID. router id router-id
3. Enable BGP and enter BGP view or BGP-VPN instance view.
4. Configure the router ID.
•
Enable BGP and enter
BGP view: bgp as-number
•
Enable BGP and enter
BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
router-id { router-id | auto-select }
Remarks
N/A
By default, no global router ID is configured, and BGP uses the highest loopback interface IP address—if any—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.
By default, BGP is not enabled.
A router can reside in only one AS, so the router can run only one BGP process.
To enter BGP-VPN instance view, the specified VPN instance must already exist and have the route distinguisher (RD) configured. For more information, see MPLS
Configuration Guide .
By default, the global router ID is used.
The auto-select keyword is supported only in BGP-VPN instance view.
Configuring a BGP peer
Configuring an IPv4 BGP peer
Step
1. Enter system view.
Command system-view
Remarks
N/A
192
Step
2. Enter BGP view or BGP-VPN instance view.
3. Create an IPv4 BGP peer and specify its AS number.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name peer ip-address as-number as-number
4. (Optional.) Configure a description for a peer. peer ip-address description
description-text
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.
Configuring an IPv6 BGP peer
peer ip-address enable
Remarks
N/A
By default, no IPv4 BGP peer is created.
By default, no description is configured for a peer.
By default, the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family is not created.
By default, the router cannot exchange IPv4 unicast routing information with the peer.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
N/A
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
description-text
5. Create the BGP IPv6 unicast address family or BGP-VPN
IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
By default, no IPv6 BGP peer is created.
BGP can use an IPv6 link-local address to establish a peer relationship with a peer when the following conditions exist:
•
The IPv6 link-local address belongs to the interface directly connected to the local router.
•
The peer connect-interface command is configured on the peer to specify the interface as the source interface.
By default, no description is configured for a peer.
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
193
Step
6. Enable the router to exchange IPv6 unicast routing information with the specified peer.
Command
peer ipv6-address enable
Remarks
By default, the router cannot exchange IPv6 unicast routing information with the peer.
Configuring dynamic BGP peers
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.
Configuring dynamic BGP peers (IPv4 unicast address family)
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or
BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Specify devices in a network as dynamic BGP peers and specify an AS number for the peers.
4. (Optional.) Configure a description for dynamic
BGP peers.
peer ip-address
as-number as-number peer ip-address description mask-length
mask-length
description-text
5. Create the BGP IPv4 unicast address family or
BGP-VPN IPv4 unicast address family and enter its view.
6. Enable BGP to exchange
IPv4 unicast routing information with dynamic
BGP peers in the specified network. address-family ipv4 [ unicast ]
peer ip-address mask-length enable
Configuring dynamic BGP peers (IPv6 unicast address family)
N/A
By default, no dynamic BGP peer is specified.
By default, no description is configured for dynamic BGP peers.
By default, the BGP IPv4 unicast address family or
BGP-VPN IPv4 unicast address family is not created.
By default, BGP cannot exchange IPv4 unicast routing information with dynamic BGP peers.
Step
1. Enter system view.
Command system-view
Remarks
N/A
194
Step
2. Enter BGP view or
BGP-VPN instance view.
Command
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
3. Specify devices in a network as dynamic BGP peers and specify an AS number for the peers.
4. (Optional.) Configure a description for dynamic
BGP peers.
5. Create the BGP IPv6 unicast address family or
BGP-VPN IPv6 unicast address family and enter its view.
6. Enable BGP to exchange
IPv6 unicast routing information with dynamic
BGP peers in the specified network.
peer ipv6-address prefix-length as-number as-number peer ipv6-address prefix-length description description-text address-family ipv6 [ unicast ]
peer ipv6-address prefix-length enable
By default, no dynamic BGP peer is specified.
By default, no description is configured for dynamic BGP peers.
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
By default, BGP cannot exchange
IPv6 unicast routing information with dynamic BGP peers.
Configuring a BGP peer group
The peers in a peer group use the same route selection policy.
In a large-scale network, many peers can use the same route selection policy. You can configure a peer group and add these peers into this group. When you change the policy for the group, the modification also applies to the peers in the group.
A peer group is an IBGP peer group if peers in it belong to the local AS, and is an EBGP peer group if peers in it belong to different ASs.
Configuring an IBGP peer group
After you create an IBGP peer group and then add a peer into it, the system creates the peer in BGP view and specifies the local AS number for the peer.
To configure an IBGP peer group (IPv4):
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Create an IBGP peer group. group group-name [ internal ]
N/A
By default, no IBGP peer group is created.
195
Step
4. Add a peer into the IBGP peer group.
Command peer ip-address [ mask-length ] group group-name [ as-number as-number ]
5. (Optional.) Configure a description for a peer group. peer group-name description
description-text
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
To configure an IBGP peer group (IPv6):
Remarks
By default, no peer exists in the peer group.
To use the as-number as-number option, you must specify the local
AS number.
By default, no description is configured for the peer group.
By default, the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family is not created.
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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.
5. (Optional.) Configure a description for a peer group.
Remarks
N/A
N/A
By default, no IBGP peer group is created. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
By default, no peer exists in the peer group.
To use the as-number as-number option, you must specify the local
AS number.
BGP can use an IPv6 link-local address to establish a peer relationship with a peer when the following conditions exist:
•
The IPv6 link-local address belongs to the interface directly connected to the local router.
•
The peer connect-interface command is configured on the peer to specify the interface as the source interface.
peer group-name description
description-text
By default, no description is configured for the peer group.
196
Step
6. Create the BGP IPv6 unicast address family or BGP-VPN
IPv6 unicast address family and enter its view.
Command 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
Remarks
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Configuring an EBGP peer group
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.
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.
•
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 configure an EBGP peer group by using Method 1 (IPv4):
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Create an EBGP peer group. group group-name external
N/A
4. Specify the AS number for the group.
5. Add a peer into the EBGP peer group.
peer group-name as-number as-number peer ip-address [ mask-length ] group group-name [ as-number as-number ]
6. (Optional.) Configure a description for a peer group. peer group-name description
description-text
By default, no EBGP peer group is created.
By default, no AS number is specified.
If a peer group contains peers, you cannot remove or change its
AS number.
By default, no peer exists in the peer group.
The as-number as-number option, if used, must specify the same AS number as the peer
group-name as-number as-number command.
By default, no description is configured for the peer group.
197
Step
7. Create the BGP IPv4 unicast address family or BGP-VPN
IPv4 unicast address family and enter its view.
Command 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
To configure an EBGP peer group by using Method 1 (IPv6):
Remarks
By default, the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family is not created.
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3.
4.
Create an EBGP peer group.
Specify the AS number for the group.
group group-name
peer group-name as-number external as-number
By default, no EBGP peer group is created.
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 ]
By default, no peer exists in the peer group.
The as-number as-number option, if used, must specify the same AS number as the peer
group-name as-number as-number command.
BGP can use an IPv6 link-local address to establish a peer relationship with a peer when the following conditions exist:
•
The IPv6 link-local address belongs to the interface directly connected to the local router.
•
The peer connect-interface command is configured on the peer to specify the interface as the source interface.
6. (Optional.) Configure a description for a peer group. peer group-name description
description-text
7. Create the BGP IPv6 unicast address family or BGP-VPN
IPv6 unicast address family and enter its view. address-family ipv6 [ unicast ]
By default, no description is configured for the peer group.
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
198
Step
8. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
Command
peer group-name enable
To configure an EBGP peer group by using Method 2 (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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 ip-address [ mask-length ]
as-number as-number
Remarks
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Remarks
N/A
N/A
5. Add the peer into the EBGP peer group. peer ip-address [ mask-length ] group group-name [ as-number as-number ]
6. (Optional.) Configure a description for a peer group. peer group-name description
description-text
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
To configure an EBGP peer group by using Method 2 (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
By default, no EBGP peer group is created.
By default, no IPv4 BGP peer is created.
By default, no peer exists in the peer group.
The as-number as-number option, if used, must specify the same AS number as the peer
ip-address as-number as-number command.
By default, no description is configured for the peer group.
By default, the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family is not created.
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Remarks
N/A
N/A
199
Step Command
3. Create an EBGP peer group. group group-name external
Remarks
By default, no EBGP peer group is created.
4. Create an IPv6 BGP peer and specify its AS number. peer ipv6-address [ prefix-length ]
as-number as-number
By default, no IPv6 BGP peer is created.
5. Add the peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name [ as-number as-number ]
By default, no peer exists in the peer group.
The as-number as-number option, if used, must specify the same AS number as the peer ipv6-address [ prefix-length ]
as-number as-number command.
BGP can use an IPv6 link-local address to establish a peer relationship with a peer when the following conditions exist:
•
The IPv6 link-local address belongs to the interface directly connected to the local router.
•
The peer connect-interface command is configured on the peer to specify the interface as the source interface.
6. (Optional.) Configure a description for the peer group.
7. Create the BGP IPv6 unicast address family or BGP-VPN
IPv6 unicast address family and enter its view. peer group-name
description-text description address-family ipv6 [ unicast ]
By default, no description is configured for the peer group.
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
8. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group.
peer group-name enable
To configure an EBGP peer group by using Method 3 (IPv4):
By default, the router cannot exchange IPv6 unicast routing information with the peers.
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Create an EBGP peer group. group group-name external
N/A
By default, no EBGP peer group is created.
4. Add a peer into the EBGP peer group. peer ip-address [ mask-length ] group group-name as-number as-number
By default, no peer exists in the peer group.
200
Step
5. (Optional.) Configure a description for the peer group.
Command peer group-name description
description-text
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
To configure an EBGP peer group by using Method 3 (IPv6):
Remarks
By default, no description is configured for the peer group.
By default, the BGP IPv4 unicast address family or BGP-VPN IPv4 unicast address family is not created.
By default, the router cannot exchange IPv4 unicast routing information with the peers.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Create an EBGP peer group. group group-name external
By default, no EBGP peer group is created.
4. Add a peer into the EBGP peer group. peer ipv6-address [ prefix-length ] group group-name as-number as-number
By default, no peer exists in the peer group.
BGP can use an IPv6 link-local address to establish a peer relationship with a peer when the following conditions exist:
•
The IPv6 link-local address belongs to the interface directly connected to the local router.
•
The peer connect-interface command is configured on the peer to specify the interface as the source interface.
5. (Optional.) Configure a description for the peer group.
6. Create the BGP IPv6 unicast address family or BGP-VPN
IPv6 unicast address family and enter its view. peer group-name
description-text description address-family ipv6 [ unicast ]
By default, no description is configured for the peer group.
By default, the BGP IPv6 unicast address family or BGP-VPN IPv6 unicast address family is not created.
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.
201
Specifying the source address of TCP connections
By default, BGP uses the primary IPv4/IPv6 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.
Change the source address in the following scenarios:
•
If the peer's IPv4/IPv6 address belongs to an interface indirectly connected to the local router, specify that interface as the source interface for TCP connections on the peer. For example, interface A on the local end is directly connected to interface B on the peer. If you use the peer x.x.x.x as-number as-number command on the local end, and x.x.x.x is not the IPv4 address of interface B, you must do the following: a. Use the peer connect-interface command on the peer. b. Specify the interface whose IPv4 address is x.x.x.x as the source interface.
•
If the source interface fails on a BGP router that has multiple links to a peer, BGP must re-establish TCP connections. To avoid this problem, use a loopback interface as the source interface or use the IP address of a loopback interface as the source address.
•
If the BGP sessions use the IP addresses of different interfaces, specify a source address or source interface for each peer to establish multiple BGP sessions to a router. Specify a source address for each peer if the BGP sessions use the different addresses of the same interface.
Otherwise, the local BGP router might fail to establish a TCP connection to a peer when it uses the optimal route to determine the source address.
To specify the source address of TCP connections (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Specify the source IPv4 address of TCP connections to a peer or peer group.
4. Specify the source interface of TCP connections to a peer or peer group. peer ipv4-address [ mask-length ] source-address source-ipv4-address peer group-name source-address source-ipv4-address peer { group-name
[ mask-length ] }
| ip-address connect-interface interface-type interface-number
The peer source-address command is available in Release
1121 and later.
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.
To specify the source interface for TCP connections (IPv6):
Step
1. Enter system view.
Command system-view
Remarks
N/A
202
Step
2. Enter BGP view or BGP-VPN instance view.
3. Specify the source IPv6 address of TCP connections to a peer or peer group.
4. Specify the source interface for establishing TCP connections to a peer or peer group.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A peer ipv6-address
[ prefix-length source-ipv6-address peer
] source-address group-name source-address source-ipv6-address peer { group-name | ipv6-address
[ prefix-length ] } connect-interface interface-type interface-number
The peer source-address command is available in Release
1121 and later.
By default, BGP uses the primary
IPv6 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.
Generating BGP routes
BGP can generate routes in the following ways:
•
Advertise local networks.
•
Redistribute IGP routes.
Injecting a local network
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.
To inject a local network (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Inject a local network to the
BGP routing table. network ip-address [ mask | mask-length ] [ route-policy route-policy-name ]
By default, BGP does not advertise any local network.
203
To inject a local network (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Inject a local network to the
IPv6 BGP routing table. network ipv6-address prefix-length [ route-policy route-policy-name ]
By default, BGP does not advertise any local network.
Redistributing IGP routes
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.
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.
The ORIGIN attribute of BGP routes redistributed from IGPs is INCOMPLETE.
To configure BGP to redistribute IGP routes (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Enable route redistribution from the specified IGP into
BGP. import-route protocol
[ { process-id | all-processes }
[ allow-direct | med med-value |
route-policy route-policy-name ]
* ]
5. (Optional.) Enable default route redistribution into BGP. default-route imported
To configure BGP to redistribute IGP routes (IPv6):
By default, BGP does not redistribute IGP routes.
By default, BGP does not redistribute default routes.
204
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Enable route redistribution from the specified IGP into
BGP. import-route protocol
[ process-id [ allow-direct | med med-value | route-policy route-policy-name ] * ]
5. (Optional.) Enable default route redistribution into BGP. default-route imported
By default, BGP does not redistribute IGP routes.
By default, BGP does not redistribute default routes.
Controlling route distribution and reception
This section describes how to control route distribution and reception.
Configuring BGP route summarization
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.
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
Automatic route summarization enables BGP to summarize IGP subnet routes redistributed by the import-route command so BGP advertises only natural network routes.
To configure automatic route summarization (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
205
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Configure automatic route summarization. address-family ipv4 [ unicast ] N/A summary automatic
Remarks
N/A
By default, automatic route summarization is not configured.
Configuring manual route summarization
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.
To configure BGP manual route summarization (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Create a summary route in the BGP routing table. aggregate ip-address { mask | mask-length } [ as-set | attribute-policy route-policy-name | detail-suppressed | origin-policy route-policy-name | suppress-policy route-policy-name ] *
To configure BGP manual route summarization (IPv6):
By default, no summary route is configured.
Step
1. Enter system view.
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
206
Step
4. Create a summary route in the IPv6 BGP routing table.
Command aggregate ipv6-address prefix-length [ as-set | attribute-policy route-policy-name | detail-suppressed | origin-policy route-policy-name | suppress-policy route-policy-name ] *
Remarks
By default, no summary route is configured.
Advertising optimal routes in the IP routing table
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 to all BGP peers.
To enable BGP to advertise optimal routes in the IP routing table:
Step Command
1. Enter system view.
system-view
2. Enter BGP view.
3. Enable BGP to advertise optimal routes in the IP routing table. bgp as-number advertise-rib-active
Remarks
N/A
N/A
By default, BGP advertises optimal routes in the BGP routing table.
Advertising a default route to a peer or peer group
Perform this task to advertise a default BGP route with the next hop being the advertising router to a peer or peer group.
To advertise a default route to a peer or peer group (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Advertise a default route to a peer or peer group. peer { group-name | ip-address
[ mask-length ] } default-route-advertise
[ route-policy route-policy-name ]
To advertise a default route to a peer or peer group (IPv6):
By default, no default route is advertised.
207
Step
1. Enter system view.
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. 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.
Limiting routes received from a peer or peer group
This feature can prevent attacks that send a large number of BGP routes to the router.
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 specified 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.
To limit routes that a router can receive from a peer or peer group (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Specify the maximum number of routes that a router can receive from a peer or peer group. peer { group-name | ip-address
[ mask-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.
To limit routes that a router can receive from a peer or peer group (IPv6):
208
Step
1. Enter system view.
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
4. Specify the maximum number of routes that a router can receive from a peer or peer group.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A peer { group-name | 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 filtering policies
Configuration 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 ").
Configuring BGP route distribution filtering policies
To configure BGP route distribution filtering policies, use the following methods:
•
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.
If you configure multiple filtering policies, apply them in the following sequence:
1. filter-policy export
2. peer filter-policy export
3. peer as-path-acl export
4. peer prefix-list export
5. peer route-policy export
Only routes passing all the configured policies can be advertised.
To configure BGP route distribution filtering policies (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
209
Step
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Command Remarks address-family ipv4 [ unicast ] N/A
4. Configure BGP route distribution filtering policies.
•
Reference an ACL or IP prefix list to filter advertised
BGP routes: filter-policy { acl-number | prefix-list prefix-list-name } export [ direct | isis process-id | ospf process-id | rip process-id | static ]
•
Reference a routing policy to filter BGP routes advertised to a peer or peer group: peer { group-name | ip-address [ mask-length ] } route-policy route-policy-name export
•
Reference an ACL to filter
BGP routes advertised to a peer or peer group: peer { group-name | ip-address [ mask-length ] } filter-policy acl-number export
•
Reference an AS path list to filter BGP routes advertised to a peer or peer group: peer { group-name | ip-address [ mask-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 | ip-address [ mask-length ] } prefix-list prefix-list-name export
Use at least one method.
By default, no BGP distribution filtering policy is configured.
To configure BGP route distribution filtering policies (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
210
Step
4. Configure BGP route distribution filtering policies.
Command
•
Reference an ACL or IPv6 prefix list to filter advertised
BGP routes: filter-policy { acl6-number | prefix-list ipv6-prefix-name } export [ direct | isisv6 process-id | ospfv3 process-id | ripng process-id
| static ]
•
Reference a routing policy to filter BGP routes advertised to a peer or peer group: peer { group-name | 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 | ipv6-address
[ prefix-length ] } filter-policy acl6-number export
•
Reference an AS path list to filter BGP routes advertised to a peer or peer group: peer { group-name | 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 | ipv6-address
[ prefix-length ] } prefix-list ipv6-prefix-name export
Remarks
Use at least one method.
Not configured by default.
Configuring BGP route reception filtering policies
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.
If you configure multiple filtering policies, apply them in the following sequence:
1. filter-policy import
2. peer filter-policy import
3. peer as-path-acl import
4. peer prefix-list import
5. peer route-policy import
Only routes passing all the configured policies can be received.
To configure BGP route reception filtering policies (IPv4):
211
Step
1. Enter system view.
Command
2. Enter BGP view or BGP-VPN instance view. system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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. Configure BGP route reception filtering policies.
•
Reference an ACL or IP prefix list to filter BGP routes received from all peers: filter-policy { acl-number |
prefix-list prefix-list-name } import
•
Reference a routing policy to filter
BGP routes received from a peer or peer group: peer { group-name | ip-address
[ mask-length ] } route-policy route-policy-name import
•
Reference an ACL to filter BGP routes received from a peer or peer group: peer { group-name | ip-address
[ mask-length ] } filter-policy
acl-number import
•
Reference an AS path list to filter
BGP routes received from a peer or peer group: peer { group-name | ip-address
[ mask-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 | ip-address
[ mask-length ] } prefix-list
prefix-list-name import
To configure BGP route reception filtering policies (IPv6):
Remarks
N/A
N/A
N/A
Use at least one method.
By default, no route reception filtering is configured.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view. address-family ipv6 [ unicast ]
Remarks
N/A
N/A
N/A
212
Step
4. Configure BGP route reception filtering policies.
Command
•
Reference ACL or IPv6 prefix list to filter BGP routes received from all peers: filter-policy { acl6-number |
prefix-list ipv6-prefix-name } import
•
Reference a routing policy to filter
BGP routes received from a peer or peer group: peer { group-name | 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 | ipv6-address
[ prefix-length ] } filter-policy
acl6-number import
•
Reference an AS path list to filter
BGP routes received from a peer or peer group: peer { group-name | 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 | ipv6-address
[ prefix-length ] } prefix-list ipv6-prefix-name import
Remarks
Use at least one method.
By default, no route reception filtering is configured.
Configuring BGP update sending delay
Perform this task to configure BGP to delay sending updates on reboot. After this feature is configured, BGP redistributes all routes from other neighbors on reboot, and then advertises the optimal route. This configuration reduces traffic loss due to the reboot.
To configure BGP update sending delay:
Step
1. Enter system view.
system-view
2. Enter BGP view.
3. Configure BGP update sending delay.
4. Configure BGP to immediately send updates for routes that match a prefix list on reboot.
Command bgp as-number
bgp update-delay on-startup seconds bgp update-delay on-startup prefix-list
prefix-list-name
Remarks
N/A
N/A
By default, BGP immediately sends updates on reboot.
By default, BGP delays sending updates for all routes on reboot.
Use this command when updates for routes that match a prefix list must be sent immediately.
213
Configuring BGP route dampening
Route dampening enables BGP to not select unstable routes as optimal routes. This feature applies to EBGP routes but not to IBGP routes.
To configure BGP route dampening (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name address-family ipv4 [ unicast ]
4. Configure BGP route dampening. dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ] *
To configure BGP route dampening (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Configure IPv6 BGP route dampening. dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ] *
Remarks
N/A
N/A
N/A
By default, BGP route dampening is not configured.
Remarks
N/A
N/A
N/A
By default, IPv6 BGP route dampening is not configured.
Controlling BGP path selection
By configuring BGP path attributes, you can control BGP path selection.
Specifying a preferred value for routes received
Perform this task to set a preferred value for specific routes to control BGP path selection.
214
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.
To specify a preferred value for routes from a peer or peer group (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Specify a preferred value for routes received from a peer or peer group. peer { group-name | ip-address
[ mask-length ] } preferred-value value
The default preferred value is 0.
To specify a preferred value for routes from a peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Specify a preferred value for routes received from a peer or peer group. peer { group-name | ipv6-address
[ prefix-length ] } preferred-value value
The default preferred value is 0.
Configuring preferences for BGP routes
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 reference 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. You can use the network short-cut command to configure the EBGP route as a shortcut
215
route that has the same preference as the local BGP route. The EBGP route will more likely become the optimal route.
To configure preferences for BGP routes (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Configure preferences for
EBGP, IBGP, and local BGP routes. preference { external-preference internal-preference local-preference | route-policy route-policy-name }
5. Configure an EBGP route as a shortcut route. network ip-address [ mask | mask-length ] short-cut
To configure preferences for BGP routes (IPv6):
The default preferences for
EBGP, IBGP, and local BGP routes are 255, 255, and 130.
By default, an EBGP route has a preference of 255.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Configure preferences for
EBGP, IBGP, and local BGP routes.
5. Configure an EBGP route as a shortcut route. preference { external-preference internal-preference local-preference | route-policy route-policy-name } network ipv6-address
prefix-length short-cut
The default preferences for
EBGP, IBGP, and local BGP routes are 255, 255, and 130.
By default, an EBGP route has a preference of 255.
Configuring the default local preference
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 considers 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.
216
To specify the default local preference (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view. address-family ipv4 [ unicast ] N/A
4. Configure the default local preference. default local-preference value
To specify the default local preference (IPv6):
The default local preference is
100.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Configure the default local preference. default local-preference value
The default local preference is
100.
Configuring 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 considers the route with the smallest MED value as the optimal route if other conditions are the same.
Configuring the default MED value
To configure the default MED value (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
217
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Configure the default MED value. address-family ipv4 [ unicast ] N/A
default med med-value
Remarks
N/A
The default MED value is 0.
To configure the default MED value (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
4. Configure the default MED value. address-family ipv6 [ unicast ] N/A
default med med-value
Enabling MED comparison for routes from different ASs
The default MED value is 0.
This task enables BGP to compare the MEDs of routes from different ASs.
To enable MED comparison for routes from different ASs (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Enable MED comparison for routes from different ASs.
Remarks
N/A address-family ipv4 [ unicast ] N/A compare-different-as-med
N/A
By default, this feature is disabled.
218
To enable MED comparison for routes from different ASs (IPv6):
Step
1. Enter system view.
2. Enter BGP view.
Command system-view bgp as-number
Remarks
N/A
N/A
3. Enter BGP IPv6 unicast address family view.
4. Enable MED comparison for routes from different ASs. address-family ipv6 [ unicast ] N/A compare-different-as-med
Enabling MED comparison for routes on a per-AS basis
By default, this feature is disabled.
This task enables BGP to compare the MEDs of routes from an AS.
Figure 57 Route selection based on MED (in an IPv4 network)
AS 400
Router E
10.0.0.0
AS 200
Router ID : 3.3.3.3
Router A
Eth1/1
3.3.3.3/24
Router ID : 1.1.1.1
Router C
Eth1/1
1.1.1.1
Router ID : 2.2.2.2
AS 300
Router B
Eth1/1
2.2.2.2/24
AS 100
Router D
As shown in Figure 57 , Router D learns network 10.0.0.0 from both Router A and Router B. Because
Router B has a smaller router ID, the route learned from Router B is optimal.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0 2.2.2.2 50 0 300e
* i 3.3.3.3 50 0 200e
When Router D learns network 10.0.0.0 from Router C, it compares the route with the optimal route in its routing table. Because Router C and Router B reside in different ASs, BGP does not compare the MEDs of the two routes. Router C has a smaller router ID than Router B so the route from Router
C becomes optimal.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0 1.1.1.1 60 0 200e
* i 10.0.0.0 2.2.2.2 50 0 300e
* i 3.3.3.3 50 0 200e
However, Router C and Router A reside in the same AS, and Router C has a greater MED, so network 10.0.0.0 learned from Router 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 Router D. After that, Router D puts the routes received from each AS into a group, selects the route with the lowest MED from each group, and compares
219
routes from different groups. The following output shows the BGP routing table on Router D after this feature is enabled. Network 10.0.0.0 learned from Router B is the optimal route.
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0 2.2.2.2 50 0 300e
* i 3.3.3.3 50 0 200e
* i 1.1.1.1 60 0 200e
To enable MED comparison for routes on a per-AS basis (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Enable MED comparison for routes on a per-AS basis.
Remarks
N/A address-family ipv4 [ unicast ] N/A bestroute compare-med
N/A
By default, this feature is disabled.
To enable MED comparison for routes on a per-AS basis (IPv6):
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
4. Enable MED comparison for routes on a per-AS basis. bgp as-number address-family ipv6 [ unicast ] N/A bestroute compare-med
N/A
By default, this feature is disabled.
Enabling MED comparison for routes from confederation peers
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.
To enable MED comparison for routes from confederation peers (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
220
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Enable MED comparison for routes from confederation peers. address-family ipv4 [ unicast ] N/A bestroute med-confederation By default, this feature is disabled.
To enable MED comparison for routes from confederation peers (IPv6):
Step
1. Enter system view.
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
4. Enable MED comparison for routes from confederation peers.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A bestroute med-confederation By default, this feature is disabled.
Configuring the NEXT_HOP attribute
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 make sure the BGP peer can find the correct next hop.
For example, as shown in Figure 58 , 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 58 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 59 , 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.
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Figure 59 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
IMPORTANT:
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.
To configure the NEXT_HOP attribute (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Specify the router as the next hop for routes sent to a peer or peer group. peer { group-name | ip-address } 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.
To configure the NEXT_HOP attribute (IPv6):
Step
1. Enter system view.
2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Specify the router as the next hop for routes sent to a peer or peer group. peer { group-name | ipv6-address } 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.
222
Configuring the AS_PATH attribute
Permitting local AS number to appear in routes from a peer or peer group
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.
To permit the local AS number to appear in routes from a peer or peer group and specify the appearance times (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Permit the local AS number to appear in routes from a peer or peer group and specify the appearance times. address-family ipv4 [ unicast ] N/A peer { group-name | ip-address
[ mask-length ] } allow-as-loop
[ number ]
By default, the local AS number is not allowed in routes from a peer or peer group.
To permit the local AS number to appear in routes from a peer or peer group and specify the appearance times (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
4. Permit the local AS number to appear in routes from a peer or peer group and specify the appearance times.
Remarks
N/A address-family ipv6 [ unicast ] N/A peer { group-name | ipv6-address
[ prefix-length ] } allow-as-loop
[ number ]
N/A
By default, the local AS number is not allowed in routes from a peer or peer group.
223
Disabling BGP from considering AS_PATH during optimal route selection
To disable BGP from considering AS_PATH during optimal route selection (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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 ]
Remarks
N/A
N/A
N/A
4. Disable BGP from considering AS_PATH during optimal route selection. bestroute as-path-neglect
By default, BGP considers
AS_PATH during optimal route selection.
To disable BGP from considering AS_PATH during optimal route selection (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
4. Disable BGP from considering AS_PATH during optimal route selection. address-family ipv6 [ unicast bestroute as-path-neglect
]
Advertising a fake AS number to a peer or peer group
Remarks
N/A
N/A
N/A
By default, BGP considers
AS_PATH during optimal route selection.
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.
To advertise a fake AS number to a peer or peer group (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
224
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
3. Advertise a fake AS number to a peer or peer group. peer { group-name | ip-address
[ mask-length ] } fake-as
as-number
By default, no fake AS number is advertised to a peer or peer group.
This command applies only to
EBGP peers or EBGP peer groups.
To advertise a fake AS number to a peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Advertise a fake AS number to a peer or peer group.
Remarks
N/A
N/A 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.
This command applies only to
EBGP peers or EBGP peer groups.
Configuring AS number substitution
IMPORTANT:
Do not configure AS number substitution in normal circumstances. Otherwise, routing loops might occur.
To use BGP 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.
225
Figure 60 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
For example, as shown in Figure 60 , 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.
To configure AS number substitution for a peer or peer group (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Configure AS number substitution for a peer or peer group. peer { group-name | ip-address
[ mask-length ] } substitute-as
Remarks
N/A
N/A
By default, AS number substitution is not configured.
To configure AS number substitution for a peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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
Remarks
N/A
N/A
By default, AS number substitution is not configured.
Removing private AS numbers from updates sent to an EBGP peer or peer group
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.
To remove private AS numbers from updates sent to an EBGP peer or peer group (IPv4):
226
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Configure BGP to remove private AS numbers from the
AS_PATH attribute of updates sent to an EBGP peer or peer group. address-family ipv4 [ unicast ] N/A peer { group-name | ip-address
[ mask-length ] } public-as-only
By default, this feature is not configured.
This command is only applicable to EBGP peers or peer groups.
To remove private AS numbers from updates sent to an EBGP peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
4. Configure BGP to remove private AS numbers from the
AS_PATH attribute of updates sent to an EBGP peer or peer group. address-family ipv6 [ unicast ] N/A peer { group-name | ipv6-address
[ prefix-length ] } public-as-only
Ignoring the first AS number of EBGP route updates
By default, this feature is not configured.
This command is only applicable to EBGP peers or peer groups.
By default, BGP checks the first AS number of a received EBGP route update. If the first AS number is neither the AS number of the EBGP peer nor a private AS number, the BGP router disconnects the
BGP session to the peer.
To ignore the first AS number of EBGP route updates:
Step
1. Enter system view.
2. Enter BGP view.
3. Configure BGP to ignore the first AS number of EBGP route updates.
Command system-view bgp as-number ignore-first-as
Remarks
N/A
N/A
By default, BGP checks the first AS number of EBGP route updates.
227
Tuning and optimizing BGP networks
This section describes how to tune and optimize BGP networks.
Configuring the keepalive interval and hold time
BGP sends keepalive messages at a specific interval 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 specific 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 0 and the negotiated hold time is not 0, the actual keepalive interval equals 1/3 of the hold time. 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.
To configure the keepalive interval and hold time (IPv4):
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
N/A
3. Configure the keepalive interval and hold time.
•
Configure the global keepalive interval and hold time:
timer keepalive keepalive hold holdtime
•
Configure the keepalive interval and hold time for a peer or peer group: peer { group-name | ip-address [ mask-length ] } timer keepalive keepalive hold holdtime
Use at least one method.
By default, the keepalive interval is 60 seconds, and hold time is
180 seconds.
The timer command takes effect for new BGP sessions and does not affect existing sessions.
If you modify the timers with the peer timer command, BGP immediately closes the existing
BGP session and creates a new session to the peer by using the new settings.
The holdtime must be at least three times the keepalive interval.
To configure the keepalive interval and hold time (IPv6):
Step
1. Enter system view.
Command system-view
Remarks
N/A
228
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
3. Configure the keepalive interval and hold time.
•
Configure the global keepalive interval and hold time:
timer keepalive keepalive hold holdtime
•
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
Use at least one method.
By default, the keepalive interval is 60 seconds, and hold time is
180 seconds.
The timer command takes effect for new BGP sessions and does not affect existing sessions.
If you modify the timers with the peer timer command, BGP immediately closes the existing
BGP session and creates a new session to the peer by using the new settings.
The holdtime must be at least three times the keepalive interval.
Configuring the interval for sending updates for the same route
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.
To configure the interval for sending the same update to a peer or peer group (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Configure the interval for sending updates for the same route to a peer or peer group. peer { group-name | ip-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.
To configure the interval for sending the same update to a peer or peer group (IPv6):
Step
1. Enter system view.
Command system-view
Remarks
N/A
229
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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
Remarks
N/A
By default, the interval is 15 seconds for an IBGP peer and 30 seconds for an EBGP peer.
Enabling BGP to establish an EBGP session over multiple hops
IMPORTANT:
When GTSM is configured, the local device can establish an EBGP session with the peer after both devices pass GTSM check, regardless of whether the maximum number of hops is reached.
To establish an EBGP connection, two routers must have a direct physical link. 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.
If directly connected EBGP peers use loopback interfaces to establish a BGP session, you do not need to configure the peer ebgp-max-hop command.
To enable BGP to establish an indirect EBGP session (IPv4):
Remarks
N/A
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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 | ip-address
[ mask-length ] } ebgp-max-hop
[ hop-count ]
To enable BGP to establish an indirect EBGP session (IPv6):
Step
1. Enter system view.
Command system-view
N/A
By default, BGP cannot establish an EBGP session to an indirectly-connected peer or peer group.
Remarks
N/A
230
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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 ]
Remarks
N/A
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
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.
To enable immediate re-establishment of direct EBGP connections:
Step
1. Enter system view.
2. Enter BGP view.
Command system-view bgp as-number
3. Enable immediate re-establishment of direct EBGP connections upon link failure. ebgp-interface-sensitive
Remarks
N/A
N/A
By default, this feature is enabled.
Enabling 4-byte AS number suppression
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 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 function. 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.
If the peer device supports 4-byte AS numbers, do not enable the 4-byte AS number suppression function. Otherwise, the BGP session cannot be established.
To enable 4-byte AS number suppression (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
231
Step
2. Enter BGP view or BGP-VPN instance view.
3. Enable 4-byte AS number suppression.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name peer { group-name | ip-address
[ mask-length ] } capability-advertise suppress-4-byte-as
To enable 4-byte AS number suppression (IPv6):
Remarks
N/A
By default, 4-byte AS number suppression is not enabled.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable 4-byte AS number suppression.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name peer { group-name | ipv6-address
[ prefix-length ] } capability-advertise suppress-4-byte-as
Remarks
N/A
N/A
By default, 4-byte AS number suppression is not enabled.
Enabling MD5 authentication for BGP peers
MD5 authentication provides the following benefits:
•
Peer authentication makes sure that only BGP peers that have the same password can establish TCP connections.
•
Integrity check makes sure that BGP packets exchanged between peers are intact.
To enable MD5 authentication for BGP peers (IPv4):
Remarks
N/A
Step Command
1. Enter system view.
system-view
2. Enter BGP view or BGP-VPN instance view.
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number
3. Enable MD5 authentication for a BGP peer group or peer.
b. ip vpn-instance vpn-instance-name peer { group-name | ip-address
[ mask-length ] } password
{ cipher | simple } password
To enable MD5 authentication for BGP peers (IPv6):
N/A
By default, MD5 authentication is disabled.
232
Step Command
1. Enter system view.
system-view
2. Enter BGP view or BGP-VPN instance view.
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number
3. Enable MD5 authentication for a BGP peer group or peer.
b. ip vpn-instance vpn-instance-name peer { group-name | ipv6-address
[ prefix-length ] } password
{ cipher | simple } password
Remarks
N/A
N/A
By default, MD5 authentication is disabled.
Configuring BGP load balancing
Perform this task to specify the maximum number of BGP ECMP routes for load balancing.
To specify the maximum number of BGP ECMP routes for load balancing (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Specify the maximum number of BGP ECMP routes for load balancing. address-family ipv4 [ unicast ] N/A balance { [ ebgp | eibgp | ibgp ] number | as-path-neglect }
By default, load balancing is disabled.
To specify the maximum number of BGP ECMP routes for load balancing (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
233
Step
4. Specify the maximum number of BGP ECMP routes for load balancing.
Command balance { [ ebgp | eibgp | ibgp ] number | as-path-neglect }
Remarks
By default, load balancing is disabled.
With the as-path-neglect keyword specified, the balance command enables BGP to implement load balancing over routes with different AS_PATH attributes. Use the as-path-neglect keyword according to your network, and make sure a routing loop does not occur.
Configuring IPsec for IPv6 BGP
Perform this task to configure IPsec for IPv6 BGP. IPsec can provide privacy, integrity, and authentication for IPv6 BGP packets exchanged between BGP peers.
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.
To configure IPsec for IPv6 BGP packets:
Step Command
1. Enter system view.
system-view
2. Configure an IPsec transform set and a manual
IPsec profile.
See Security Configuration Guide .
3. Enter BGP view or BGP-VPN instance view.
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
By default, no IPsec transform set or manual IPsec profile exists.
N/A
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 any IPv6 BGP peer or peer group.
This command supports only
IPsec profiles in manual mode.
Disabling BGP to establish a session to a peer or peer group
This task enables you to temporarily tear down the BGP session to a specific peer or peer group.
Then you can perform network upgrade and maintenance without needing to delete and reconfigure the peer or peer group. To recover the session, execute the undo peer ignore command.
To disable BGP to establish a session to a peer or peer group (IPv4):
Step
1. Enter system view.
Command system-view
Remarks
N/A
234
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-numbe r b. ip vpn-instance
vpn-instance-name
3. Disable BGP to establish a session to a peer or peer group. peer { group-name | ip-address
[ mask-length ] } ignore
Remarks
N/A
By default, BGP can establish a session to a peer or peer group.
To disable BGP to establish a session to a peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Disable BGP to establish a session to a peer or peer group. peer { group-name | ipv6-address
[ prefix-length ] } ignore
Remarks
N/A
N/A
By default, BGP can establish a session to a peer.
Configuring GTSM for BGP
IMPORTANT:
•
When GTSM is configured, the local device can establish an EBGP session with 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.
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.
To configure GTSM for BGP (IPv4 unicast/multicast address family):
Step
1. Enter system view.
Command system-view
Remarks
N/A
235
Step
2. Enter BGP view or
BGP-VPN instance view.
Command
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Configure GTSM for the specified BGP peer or peer group. peer { group-name | ip-address
[ mask-length ] } ttl-security hops
hop-count
To configure GTSM for BGP (IPv6 unicast/multicast address family):
Step
1. Enter system view.
2. Enter BGP view or
BGP-VPN instance view.
3. Configure GTSM for the specified BGP peer or peer group.
Command system-view
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view:
a. bgp as-number b. ip vpn-instance
vpn-instance-name peer { group-name | ipv6-address
[ prefix-length ] } ttl-security hops
hop-count
Remarks
N/A
By default, GTSM is not configured.
Remarks
N/A
N/A
By default, GTSM is not configured.
Configuring 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:
•
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
To enable BGP route refresh for a peer or peer group (IPv4):
236
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable BGP route refresh for a peer or peer group.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
•
Enable BGP route refresh for the specified peer or peer group: peer { group-name | ip-address [ mask-length ] } capability-advertise route-refresh
•
Enable BGP route refresh and multi-protocol extension capability for the specified peer or peer group: undo peer { group-name | ip-address [ mask-length ] } capability-advertise conventional
To enable BGP route refresh for a peer or peer group (IPv6):
Remarks
N/A
N/A
By default, BGP route refresh and multi-protocol extension capability are enabled.
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable BGP route refresh for a peer or peer group.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
•
Enable BGP route refresh for the specified peer or peer group: peer { group-name | ipv6-address
[ prefix-length ] } capability-advertise route-refresh
•
Enable BGP route refresh and multi-protocol extension capability for the specified peer or peer group: undo peer { group-name | ipv6-address
[ prefix-length ] } capability-advertise conventional
Remarks
N/A
N/A
By default, BGP route refresh and multi-protocol extension capability are enabled.
Saving updates
To save all route updates from the specified peer or peer group (IPv4):
237
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Remarks
N/A
N/A address-family ipv4 [ unicast ] N/A
4. Save all route updates from the peer or peer group. peer { group-name | ip-address
[ mask-length ] } keep-all-routes
By default, the routes are not saved.
This command takes effect only for the routes received after this command is executed.
To save all route updates from the specified peer or peer group (IPv6):
Step
1. Enter system view.
2. Enter BGP view
3. Enter BGP IPv6 unicast address family view.
Command system-view bgp as-number
Remarks
N/A
N/A address-family ipv6 [ unicast ] N/A
4. Save all route updates from the peer or peer group. peer { group-name | ipv6-address
[ prefix-length ] } keep-all-routes
By default, the routes are not saved.
This command takes effect only for the routes received after this command is executed.
Configuring manual soft-reset
To configure manual soft-reset (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
238
Step
3. Enable BGP route refresh for a peer or peer group.
Command
•
Enable BGP route refresh for the specified peer or peer group: peer { group-name | ip-address [ mask-length ] } capability-advertise route-refresh
•
Enable BGP route refresh and multi-protocol extension capability for the specified peer or peer group: undo peer { group-name | ip-address [ mask-length ] } capability-advertise conventional
Remarks
By default, BGP route refresh and multi-protocol extension capability are enabled.
4. Return to user view. return N/A
5. Perform manual soft-reset. refresh bgp { ip-address
[ mask-length ] | all | external |
group group-name | internal }
{ export | import } ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ]
N/A
To configure manual soft-reset (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable BGP route refresh for a peer or peer group.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
•
Enable BGP route refresh for the specified peer or peer group: peer { group-name | ipv6-address
[ prefix-length ] } capability-advertise route-refresh
•
Enable BGP route refresh and multi-protocol extension capability for the specified peer or peer group: undo peer { group-name | ipv6-address
[ prefix-length ] } capability-advertise conventional
Remarks
N/A
N/A
By default, BGP route refresh and multi-protocol extension capability are enabled.
4. Return to user view. return N/A
239
Step
5. Perform manual soft-reset.
Command Remarks refresh bgp { ipv6-address
[ prefix-length ] | all | external |
group group-name | internal }
{ export | import } ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ]
N/A
Protecting an EBGP peer when memory usage reaches level
2 threshold
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 with a specific EBGP peer when the memory usage reaches the level 2 threshold.
For more information about memory usage thresholds, see Fundamentals Configuration Guide .
To configure BGP to protect an EBGP peer or peer group when the memory usage reaches level 2 threshold (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
Remarks
N/A
N/A
3. Configure BGP to protect an
EBGP peer or peer group when the memory usage reaches level 2 threshold. peer { group-name | ip-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.
To configure BGP to protect an EBGP peer or peer group when the memory usage reaches level 2 threshold (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. 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
Remarks
N/A
N/A
By default, BGP tears down an
EBGP session to release memory resources periodically when level
2 threshold is reached.
240
Configuring a large-scale BGP network
In a large network, the number of BGP connections is huge and BGP configuration and maintenance are complicated. To simply BGP configuration, you can use the peer group, community, route reflector, and confederation features as needed. For more information about configuring peer
groups, see " Configuring a BGP peer group ."
Configuring BGP community
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 reference 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 ."
To configure BGP community (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
N/A
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view. address-family ipv4 [ unicast ] N/A
4. Advertise the COMMUNITY or extended community attribute to a peer or peer group.
•
Advertise the COMMUNITY attribute to a peer or peer group: peer { group-name | ip-address [ mask-length ] } advertise-community
•
Advertise the extended community attribute to a peer or peer group: peer { group-name | ip-address [ mask-length ] } advertise-ext-community
5. (Optional.) Apply a routing policy to routes advertised to a peer or peer group. peer { group-name | ip-address
[ mask-length ] } route-policy route-policy-name export
To configure BGP community (IPv6):
By default, the COMMUNITY or extended community attribute is not advertised.
By default, no routing policy is applied.
Step
1. Enter system view.
Command system-view
Remarks
N/A
241
Step
2. Enter BGP view.
Command bgp as-number
Remarks
N/A
3. Enter BGP IPv6 unicast address family view. address-family ipv6 [ unicast ]
4. Advertise the COMMUNITY or extended community attribute to a peer or peer group.
•
Advertise the COMMUNITY attribute to a peer or peer group: peer { group-name | ipv6-address
[ prefix-length ] } advertise-community
•
Advertise the extended community attribute to a peer or peer group: peer { group-name | ipv6-address
[ prefix-length ] } advertise-ext-community
5. (Optional.) Apply a routing policy to routes advertised to a peer or peer group. peer { group-name | ipv6-address
[ prefix-length ] } route-policy route-policy-name export
N/A
By default, the COMMUNITY or extended community attribute is not advertised.
By default, no routing policy is applied.
Configuring BGP route reflection
Configuring a BGP route reflector
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.
To configure a BGP route reflector (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
4. Configure the router as a route reflector and specify a peer or peer group as its client.
Remarks
N/A address-family ipv4 [ unicast ] N/A peer { group-name | ip-address
[ mask-length ] } reflect-client
N/A
By default, no route reflector or client is configured.
5. Enable route reflection between clients. reflect between-clients
By default, route reflection between clients is enabled.
242
Step
6. (Optional.) Configure the cluster ID of the route reflector.
Command reflector cluster-id { cluster-id | ip-address }
To configure a BGP route reflector (IPv6):
Remarks
By default, a route reflector uses its own router ID as the cluster ID.
Step
1. Enter system view.
2. Enter BGP view.
Command system-view bgp as-number
Remarks
N/A
N/A
3. Enter BGP IPv6 unicast address family view.
4. Configure the router as a route reflector and specify a peer or peer group as its client.
5. Enable route reflection between clients. address-family ipv6 [ unicast ] N/A peer { group-name | ipv6-address
[ prefix-length ] } reflect-client
By default, no route reflector or client is configured. reflect between-clients
By default, route reflection between clients is enabled.
6. (Optional.) Configure the cluster ID of the route reflector.
Ignoring the ORIGINATOR_ID attribute reflector cluster-id { cluster-id | ip-address }
By default, a route reflector uses its own router ID as the cluster ID.
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.
To ignore the ORIGINATOR_ID attribute (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
Remarks
N/A
N/A
3. Ignore the ORIGINATOR_ID attribute. peer { group-name | ip-address
[ mask-length ] } ignore-originatorid
By default, BGP does not ignore the ORIGINATOR_ID attribute.
Make sure that this command does not result in a routing loop.
After you execute this command,
BGP also ignores the
CLUSTER_LIST attribute.
To ignore the ORIGINATOR_ID attribute (IPv6):
Step
1. Enter system view.
Command system-view
Remarks
N/A
243
Step
2. Enter BGP view or BGP-VPN instance view.
Command
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name
3. Ignore the ORIGINATOR_ID attribute.
Remarks
N/A peer { group-name | ipv6-address
[ prefix-length ] } ignore-originatorid
By default, BGP does not ignore the ORIGINATOR_ID attribute.
Make sure this command does not result in a routing loop.
After you execute this command,
BGP also ignores the
CLUSTER_LIST attribute.
Configuring a 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
After you split an AS into multiple sub-ASs, configure a router in a sub-AS as follows:
1.
Enable BGP and specify the AS number of the router. For more information, see " Enabling
2. Specify the confederation ID. From an outsider's perspective, the sub-ASs of the confederation is a single AS, which is identified by the confederation ID.
3. If the router needs to establish EBGP connections to other sub-ASs, you must specify the peering sub-ASs in the confederation.
A confederation can contain a maximum of 32 sub-ASs. The AS number of a sub-AS is effective only in the confederation.
To configure a BGP confederation:
Step
1. Enter system view.
2. Enter BGP view.
Command system-view bgp as-number
Remarks
N/A
N/A
3. Configure a confederation
ID.
confederation id as-number
4. Specify confederation peer sub-ASs in the confederation.
Configuring confederation compatibility confederation peer-as as-number-list
By default, no confederation ID is configured.
By default, no confederation peer sub-AS is specified.
If any routers in the confederation do not comply with RFC 3065, enable confederation compatibility to allow the router to work with those routers.
To configure confederation compatibility:
244
Step
1. Enter system view.
2. Enter BGP view.
3. Enable confederation compatibility.
Command system-view bgp as-number confederation nonstandard
Remarks
N/A
N/A
By default, confederation compatibility is disabled.
Configuring BGP GR
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 with the GR helper. If the BGP session fails to be established within the GR timer advertised by the GR restarter, the GR helper removes the stale routes.
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 timer 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 stale routes from the RIB. The GR helper removes the stale routes.
6. The GR restarter quits the GR process if route information exchange is not completed before the RIB purge timer expires. It updates the RIB with the BGP routes already learned, and removes the stale routes.
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.
Perform the following configuration on the GR restarter and GR helper.
To configure BGP GR:
Step
1. Enter system view.
Command system-view
Remarks
N/A
245
Step
2. Enter BGP view.
4. Configure the GR timer.
Command bgp as-number
3. Enable GR capability for BGP. graceful-restart graceful-restart timer restart timer
5. Configure the maximum time to wait for the End-of-RIB marker. graceful-restart timer wait-for-rib timer
6. Configure the RIB purge timer. graceful-restart timer
purge-time timer
Remarks
N/A
By default, GR capability is disabled for BGP.
The default setting is 150 seconds.
The time that a peer waits to re-establish a session must be less than the hold time.
The default setting is 180 seconds.
The default setting is 480 seconds.
Configuring BGP NSR
BGP nonstop routing (NSR) ensures continuous routing by synchronizing BGP state and data information from the active BGP process to the standby BGP process. The standby BGP process can seamlessly take over all services when the active process fails in one of the following situations:
•
The active BGP process restarts.
•
The member device that runs the active BGP process fails.
GR and NSR have the following differences:
•
To implement NSR, the IRF fabric must have at least two member devices because the active and standby BGP processes run on different member devices. To implement GR, the IRF fabric only needs to have one member device.
•
GR requires GR-capable neighbors to help restore routing information. NSR does not need help because the standby process has all the BGP state and data information of the active process.
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 configure BGP NSR:
Step
1. Enter system view.
system-view
2.
3.
Enter BGP view.
Enable BGP NSR.
Command bgp as-number non-stop-routing
Remarks
N/A
N/A
By default, BGP NSR is disabled.
Enabling SNMP notifications for BGP
This feature enables BGP to generate SNMP notifications. The generated SNMP notifications are sent to the SNMP module.
For more information about SNMP notifications, see Network Management and Monitoring
Configuration Guide .
To enable SNMP notifications for BGP:
246
Step
1. Enter system view.
2. Enable SNMP notifications for BGP.
Command system-view snmp-agent trap enable bgp
Remarks
N/A
By default, SNMP notifications for
BGP are enabled.
Enabling logging of session state changes
Perform this task to enable BGP to log BGP session establishment and disconnection events. To view 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 .
To enable the logging of session state changes:
Step
1. Enter system view.
2. Enter BGP view.
3. Enable the logging of session state changes globally.
Command system-view bgp as-number log-peer-change
Remarks
N/A
N/A
By default, logging of session state changes is enabled globally.
Enabling logging for BGP route flapping
IMPORTANT:
This feature is available in Release 1121 and later.
This feature enables BGP to generate logs for BGP route flappings 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 .
To enable logging for BGP route flapping (IPv4 unicast):
Step
1. Enter system view.
Command system-view
Remarks
N/A
247
Step
2. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view.
Command
•
Enter BGP IPv4 unicast address family view:
a. bgp as-number b. address-family ipv4
[ unicast ]
•
Enter BGP-VPN IPv4 unicast address family view:
c. bgp as-number d. ip vpn-instance vpn-instance-name e. 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 ] *
To enable logging for BGP route flapping (IPv6 unicast):
Remarks
N/A
By default, logging for BGP route flapping is disabled.
Step
1. Enter system view.
2. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view.
3. Enable logging for BGP route flapping.
Command system-view
•
Enter BGP IPv6 unicast address family view:
a. bgp as-number b. address-family ipv6
[ unicast ]
•
Enter BGP-VPN IPv6 unicast address family view:
c. bgp as-number d. ip vpn-instance vpn-instance-name e. address-family ipv6
[ unicast ] log-route-flap monitor-time monitor-count [ log-count-limit | route-policy route-policy-name ] *
Remarks
N/A
N/A
By default, logging for BGP route flapping is disabled.
Configuring BFD for BGP
IMPORTANT:
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.
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.
For more information about BFD, see High Availability Configuration Guide .
248
Before you can enable BFD for the BGP peer, establish a BGP session between the local router and the peer.
To enable BFD for a BGP peer (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable BFD to detect the link to the specified BGP peer.
To enable BFD for a BGP peer (IPv6):
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name peer ip-address [ mask-length ] bfd
[ multi-hop | single-hop ]
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN instance view.
3. Enable BFD to detect the link to the specified IPv6 BGP peer.
Command system-view
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name peer ipv6-address [ prefix-length ] bfd
[ multi-hop | single-hop ]
Remarks
N/A
N/A
By default, BFD is not enabled.
Remarks
N/A
N/A
By default, BFD is not enabled.
Configuring 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.
Figure 61 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 61 , BGP generates a backup next hop
Router C for the primary route. BGP uses ARP, echo-mode BFD (for IPv4), or ND (for IPv6) 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 after route selection.
You can use the following methods to configure BGP FRR:
249
•
Method 1 —Execute the pic command in BGP address family view. BGP calculates a backup next hop for a BGP route in the address family if there are two or more unequal-cost routes that reaches the destination.
•
Method 2 —Execute the fast-reroute route-policy command to reference a routing policy in which a backup next hop is specified by using the apply [ ipv6 ] fast-reroute backup-nexthop command. 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, but not for IPv4 and IPv6 multicast routes.
To configure BGP FRR (IPv4 unicast address family):
Step
1. Enter system view.
Command system-view
2. Configure the source address of echo packets.
3. Create a routing policy and enter routing policy view.
4. Set the backup next hop for
FRR. bfd echo-source-ip ip-address route-policy
route-policy-name permit
node node-number apply fast-reroute
backup-nexthop ip-address quit
bgp as-number
Remarks
N/A
By default, no source address is specified for echo packets.
This step is required when echo-mode BFD 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 High Availability
Command Reference .
By default, no routing policy is created.
This step is required when Method 2 is used to enable BGP FRR.
For more information about this command, see Layer 3—IP Routing
Command Reference .
By default, no backup next hop is set.
This step is required when Method 2 is used to enable BGP FRR.
For more information about this command, see Layer 3—IP Routing
Command Reference .
N/A
N/A
5. Return to system view.
6. Enter BGP view.
7. (Optional.) Use echo-mode
BFD to detect the connectivity to the next hop of the primary route.
8. (Optional.) Enter BGP-VPN instance view.
9. Enter BGP IPv4 unicast address family view or
BGP-VPN IPv4 unicast address family view. primary-path-detect bfd echo ip vpn-instance
vpn-instance-name address-family ipv4
[ unicast ]
By default, ARP is used to detect the connectivity to the next hop.
N/A
N/A
250
Step Command Remarks
10. Enable BGP FRR.
•
(Method 1) Enable BGP
FRR for the address family: pic
•
(Method 2) Reference a routing policy to specify a backup next hop for the address family: fast-reroute route-policy
route-policy-name
By default, BGP FRR is disabled.
Method 1 might result in routing loops.
Use it with caution.
By default, no routing policy is referenced.
The apply fast-reroute backup-nexthop and apply ipv6 fast-reroute backup-nexthop commands can take effect in the referenced routing policy. Other apply commands do not take effect.
To configure BGP FRR (IPv6 unicast address family):
Step
1. Enter system view.
2. Create a routing policy and enter routing policy view.
Command system-view route-policy
route-policy-name permit
node node-number
Remarks
N/A
By default, no routing policy is created.
This step is required when Method 2 is used to enable BGP FRR.
For more information about this command, see Layer 3—IP Routing
Command Reference .
3. Set the backup next hop for
FRR. apply ipv6 fast-reroute backup-nexthop
ipv6-address
4. Return to system view.
5. Enter BGP view or BGP-VPN instance view. quit
•
Enter BGP view: bgp as-number
•
Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance
vpn-instance-name
N/A
N/A
6. Enter BGP IPv6 unicast address family view or
BGP-VPN IPv6 unicast address family view. address-family ipv6
[ unicast ]
N/A
By default, no backup next hop is set.
This step is required when Method 2 is used to enable BGP FRR.
For more information about this command, see Layer 3—IP Routing
Command Reference .
7. Enable BGP FRR.
•
(Method 1) Enable BGP
FRR for the address family: pic
•
(Method 2) Reference a routing policy to specify a backup next hop for the address family: fast-reroute route-policy
route-policy-name
By default, BGP FRR is disabled.
Method 1 might result in routing loops.
Use it with caution.
By default, no routing policy is referenced.
The apply fast-reroute backup-nexthop and apply ipv6 fast-reroute backup-nexthop commands can take effect in the referenced routing policy. Other apply commands do not take effect.
251
Configuring 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 62 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 (Provider), see MPLS Configuration Guide .
For more information about GRE, see Layer 3—IP Services Configuration Guide .
Configuring basic 6PE
Before you configure 6PE, complete 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 describes only BGP configurations on 6PE devices.
To configure basic 6PE:
Step
1. Enter system view.
2. Enter BGP view.
Command system-view bgp as-number
3. Specify a 6PE peer or peer group and its AS number. peer { group-name | ip-address
[ mask-length ] } as-number as-number
Remarks
N/A
N/A
No 6PE peer is specified by default.
252
Step
4. Enter BGP IPv6 unicast address family view.
5. Enable BGP to exchange
IPv6 unicast routing information with the 6PE peer or peer group.
6. Enable BGP to exchange labeled IPv6 routes with the 6PE peer or peer group.
Command address-family ipv6 [ unicast ] peer { group-name | ip-address
[ mask-length ] } enable peer { group-name | ip-address
[ mask-length ] } label-route-capability
Configuring optional 6PE capabilities
Remarks
N/A
This function is disabled by default.
This function is disabled by default.
Step
1. Enter system view.
Command system-view bgp as-number 2. Enter BGP view.
3. Enter BGP IPv6 unicast address family view.
4. Advertise COMMUNITY attribute to the 6PE peer or peer group. address-family ipv6 [ unicast ] peer { group-name | ip-address
[ mask-length ] }
advertise-community
5. Advertise extended community attribute to the
6PE peer or peer group. peer { group-name | ip-address
[ mask-length ] }
advertise-ext-community
6. Allow the local AS number to appear in routes from the
6PE peer or peer group and specify the repeat times. peer { group-name | ip-address
[ mask-length ] } allow-as-loop
[ number ]
Remarks
N/A
N/A
N/A
By default, the COMMUNITY attribute is not advertised.
By default, the extended community attribute is not advertised.
By default, the local AS number is not allowed to appear in routes from the 6PE peer or peer group.
7. Specify an AS path list to filter routes advertised to or received from the 6PE peer or peer group.
8. Specify an IPv6 ACL to filter routes advertised to or received from the 6PE peer or peer group.
9. Specify an IPv6 prefix list to filter routes advertised to or received from the 6PE peer or peer group.
10. Specify a routing policy to filter routes advertised to or received from the 6PE peer or peer group. peer
[ mask-length ] } as-path-acl as-path-acl-number { export | import } peer
[ mask-length acl6-number peer
[ mask-length ] } prefix-list ipv6-prefix-name { export | import } peer
{
{
{
{ group-name group-name
{
] }
| filter-policy
export group-name
group-name
|
|
| ip-address ip-address
| import ip-address
ip-address
[ mask-length ] } route-policy
} route-policy-name { export | import }
11. Advertise a default route to the 6PE peer or peer group. peer { group-name | ip-address
[ mask-length ] } default-route-advertise
[ route-policy route-policy-name ]
12. Save all routes from the 6PE peer or peer group. peer { group-name | ip-address
[ mask-length ] } keep-all-routes
By default, no AS path list is specified.
By default, no ACL is specified.
By default, no IPv6 prefix list is specified.
By default, no routing policy is specified.
By default, no default route is advertised.
By default, routes from a peer or peer group are not saved.
253
Step
13. Configure BGP updates sent to the 6PE peer or peer group to carry only the public
AS number.
Command peer { group-name | ip-address
[ mask-length ] } public-as-only
Remarks
By default, this feature is not configured.
14. Specify the maximum number of routes that BGP can receive from the 6PE peer or peer group. peer { group-name | ip-address
[ mask-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 the 6PE peer or peer group is not limited.
15. Specify a preferred value for routes received from the 6PE peer or peer group. peer { group-name | ip-address
[ mask-length ] } preferred-value
value
16. Configure the device as a route reflector and the 6PE peer or peer group as a client. peer
[
{ group-name mask-length ] }
| ip-address
reflect-client
17. Return to user view. return
By default, the preferred value is 0.
By default, no route reflector or client is configured.
N/A
18. Display information about the
6PE peer or peer group. display bgp peer ipv6 [ unicast ]
[ group-name group-name log-info | ip-address { log-info | verbose } | verbose ]
Available in any view.
19. Display routing information advertised to or received from the 6PE peer or peer group. display bgp routing-table ipv6
[ unicast ] peer ip-address
{ advertised-routes | received-routes } [ network-address prefix-length | statistics ]
Available in any view.
20. Perform soft reset on the inbound or outbound BGP
6PE connection.
21. Reset a BGP 6PE connection. refresh bgp import } ipv6 ip-address
[ unicast
reset bgp ip-address
{
] ipv6 export
[
| unicast ]
Available in user view.
Available in user view.
Displaying and maintaining BGP
Execute display commands in any view and reset commands in user view (IPv4).
Task
Display BGP NSR status information.
Display BGP IPv4 unicast peer group information.
Display BGP IPv4 unicast peer or peer group information.
Display BGP IPv4 unicast routing information.
Display BGP IPv4 unicast route advertisement information.
Command display bgp non-stop-routing status display bgp group ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ group-name group-name ] display bgp peer ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ ip-address { log-info | verbose } |
group-name group-name log-info | verbose ] display bgp routing-table ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address [ { mask | mask-length }
[ longest-match ] ] ]
display bgp routing-table ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] network-address [ mask | mask-length ] advertise-info
254
Task
Display BGP IPv4 unicast routing information sent to/received from the specified BGP peer.
Command display bgp routing-table ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] peer ip-address { advertised-routes | received-routes } [ network-address [ mask | mask-length ] | statistic ]
display bgp routing-table ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] statistic
Display BGP IPv4 unicast routing statistics.
Display BGP IPv4 unicast routing information matching the specified AS path list. display bgp routing-table ipv4 vpn-instance-name ]
[ unicast ] [ vpn-instance
as-path-acl as-path-acl-number
Display BGP IPv4 unicast routing information matching the specified BGP community list.
display bgp routing-table ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] community-list
{ { basic-community-list-number | comm-list-name }
[ whole-match ] | adv-community-list-number } display bgp routing-table dampened ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ]
Display dampened BGP IPv4 unicast routing information.
Display BGP dampening parameter information.
Display BGP IPv4 unicast routing flap statistics. display bgp dampening parameter ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] display bgp routing-table flap-info ipv4 [ unicast ]
[ vpn-instance vpn-instance-name ] [ network-address [ { mask
| mask-length } [ longest-match ] ] | as-path-acl as-path-acl-number ]
Display information about routes advertised by the network command and shortcut routes configured by the network short-cut command. display bgp network ipv4 [ unicast ] [ vpn-instance vpn-instance-name ]
Display BGP path attribute information. display bgp paths [ as-regular-expression ]
Display BGP IPv4 unicast address family update group information. display bgp update-group ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ ip-address ]
Reset all BGP sessions.
Reset IPv4 unicast BGP sessions. reset bgp all reset bgp { as-number | ip-address | all | external | group group-name | internal } ipv4 [ unicast ] [ vpn-instance vpn-instance-name ]
Clear dampened BGP IPv4 unicast routing information and release suppressed routes. reset bgp dampening ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address [ mask | mask-length ] ]
Clear BGP IPv4 unicast route flap information. reset bgp flap-info ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address [ mask | mask-length ] |
as-path-acl as-path-acl-number | peer peer-address ]
Execute display commands in any view and reset commands in user view (IPv6).
Task
Display BGP NSR status information.
Display BGP IPv6 unicast peer group information.
Command display bgp non-stop-routing status display bgp group ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ group-name group-name ]
255
Task
Display BGP IPv6 unicast peer or peer group information.
Display BGP IPv6 unicast routing information.
Command display bgp peer ipv6 [ unicast ] [ group-name group-name log-info | ip-address { log-info | verbose } | ipv6-address
{ log-info | verbose } | verbose ] display bgp peer ipv6 [ unicast ] vpn-instance vpn-instance-name [ group-name group-name log-info | ipv6-address { log-info | verbose } | verbose ]
display bgp routing-table ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address prefix-length
[ advertise-info ] ]
Display BGP IPv6 unicast routing information sent to/received from the specified BGP peer. display bgp routing-table ipv6 [ unicast ] peer { ip-address | ipv6-address } { advertised-routes | received-routes }
[ network-address prefix-length | statistics ] display bgp routing-table ipv6 [ unicast ] vpn-instance
vpn-instance-name peer ipv6-address { advertised-routes | received-routes } [ network-address prefix-length | statistics ] display bgp routing-table ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] statistics
Display BGP IPv6 unicast routing statistics.
Display BGP IPv6 unicast routing information matching the specified AS path list. display bgp routing-table ipv6 vpn-instance-name ]
[ unicast ] [ vpn-instance
as-path-acl as-path-acl-number
Display BGP IPv6 unicast routing information matching the specified BGP community list.
Display dampened BGP IPv6 unicast routing information.
Display BGP dampening parameter information.
Display BGP IPv6 unicast routing flap statistics.
display bgp routing-table ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] community-list
{ { basic-community-list-number | comm-list-name }
[ whole-match ] | adv-community-list-number } display bgp routing-table dampened ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] display bgp dampening parameter ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] display bgp routing-table flap-info ipv6 [ unicast ]
[ vpn-instance vpn-instance-name ] [ network-address
prefix-length | as-path-acl as-path-acl-number ]
Display the incoming label of BGP IPv6 unicast routing information.
Display the outgoing label of BGP IPv6 unicast routing information. display bgp routing-table ipv6 display bgp routing-table ipv6
[
[
unicast
unicast
]
] inlabel outlabel
Display information about routes advertised by the network command and shortcut routes configured by the network short-cut command. display bgp network ipv6 [ unicast ] [ vpn-instance vpn-instance-name ]
Display BGP path attribute information. display bgp paths [ as-regular-expression ]
Display BGP IPv6 unicast address family update group information.
Reset IPv6 unicast BGP sessions. display bgp update-group ipv6 [ unicast ] [ ip-address | ipv6-address ] display bgp update-group ipv6 [ unicast ] vpn-instance vpn-instance-name [ ipv6-address ] reset bgp { as-number | ipv6-address | all | external | group group-name | internal } ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] reset bgp ip-address ipv6 [ unicast ]
256
Task
Clear dampened BGP IPv6 unicast routing information and release suppressed routes.
Clear BGP IPv6 unicast route flap information.
Command reset bgp dampening ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address prefix-length ] reset bgp flap-info ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address prefix-length |
as-path-acl as-path-acl-number | peer ipv6-address ]
IPv4 BGP configuration examples
Basic BGP configuration example
Network requirements
As shown in Figure 63 , all switches run BGP. Run EBGP between Switch A and Switch B, and run
IBGP between Switch B and Switch C to allow Switch C to access network 8.1.1.0/24 connected to
Switch A.
Figure 63 Network diagram
Loop0
1.1.1.1/32
AS 65008 AS 65009
Loop0
2.2.2.2/32
Loop0
3.3.3.3/32
Vlan-int100
8.1.1.1/24
Vlan-int200
Switch A
3.1.1.2/24
EBGP
Vlan-int200
3.1.1.1/24
Switch B
Vlan-int300
9.1.1.1/24
IBGP
Vlan-int300
9.1.1.2/24
Switch C
Requirements analysis
To prevent route flapping caused by port state changes, this example uses loopback interfaces to establish IBGP connections. Because loopback interfaces are virtual interfaces, 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 make sure that Switch B can communicate with Switch C through loopback interfaces.
The EBGP peers, Switch A and Switch B (usually belong to different carriers), 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 Switch C to access the network
8.1.1.0/24 connected directly to Switch A, inject network 8.1.1.0/24 to the BGP routing table of
Switch A.
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IBGP:
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 3.3.3.3 as-number 65009
[SwitchB-bgp] peer 3.3.3.3 connect-interface loopback 0
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 3.3.3.3 enable
257
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
[SwitchB] ospf 1
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[SwitchB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 65009
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 2.2.2.2 as-number 65009
[SwitchC-bgp] peer 2.2.2.2 connect-interface loopback 0
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 2.2.2.2 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
[SwitchC] ospf 1
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 3.3.3.3 0.0.0.0
[SwitchC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
[SwitchC] display bgp peer ipv4
BGP local router ID : 3.3.3.3
Local AS number : 65009
Total number of peers : 1 Peers in established state : 1
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
2.2.2.2 65009 2 2 0 0 00:00:13 Established
The output shows that Switch C has established an IBGP peer relationship with Switch B.
3. Configure EBGP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 3.1.1.1 as-number 65009
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 3.1.1.1 enable
[SwitchA-bgp-ipv4] network 8.1.1.0 24
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
[SwitchB] bgp 65009
[SwitchB-bgp] peer 3.1.1.2 as-number 65008
258
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 3.1.1.2 enable
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Display BGP peer information on Switch B.
[SwitchB] 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
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
3.3.3.3 65009 4 4 0 0 00:02:49 Established
3.1.1.2 65008 2 2 0 0 00:00:05 Established
The output shows that Switch B has established an IBGP peer relationship with Switch C and an EBGP peer relationship with Switch A.
# Display the BGP routing table on Switch A.
[SwitchA] 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
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 Switch B.
[SwitchB] 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
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 Switch C.
[SwitchC] display bgp routing-table ipv4
Total number of routes: 1
259
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
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 Switch A has learned no route to AS 65009, and Switch 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 Switch B, so that Switch A can obtain the route to
9.1.1.0/24, and Switch C can obtain the route to 3.1.1.0/24.
# Configure Switch B.
[SwitchB] bgp 65009
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] import-route direct
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Display the BGP routing table on Switch A.
[SwitchA] 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
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 Switch A's routing table.
# Display the BGP routing table on Switch C.
[SwitchC] 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
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
260
* >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 becomes valid with the next hop as Switch A.
Verifying the configuration
# Ping 8.1.1.1 from Switch C.
[SwitchC] 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=254 time=10.000 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=4.000 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 = 3.000/4.800/10.000/2.638 ms
BGP and IGP route redistribution configuration example
Network requirements
As shown in Figure 64 , 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 Switch A to access network 9.1.2.0/24 in AS
65009, and Switch C to access network 8.1.1.0/24 in AS 65008.
Figure 64 Network diagram
Loop0
1.1.1.1/32
AS 65008 AS 65009
Loop0
2.2.2.2/32
Loop0
3.3.3.3/32
Vlan-int100
8.1.1.1/24
Vlan-int200
Switch A
3.1.1.2/24
EBGP
Vlan-int200
3.1.1.1/24
Switch B
Vlan-int300
9.1.1.1/24
OSPF
Vlan-int300
9.1.1.2/24
Switch C
Vlan-int400
9.1.2.1/24
Requirements analysis
Configure BGP to redistribute routes from OSPF on Switch B, so Switch A can obtain the route to
9.1.2.0/24. Configure OSPF to redistribute routes from BGP on Switch B, so Switch C can obtain the route to 8.1.1.0/24.
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF:
Enable OSPF in AS 65009, so Switch B can obtain the route to 9.1.2.0/24.
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ospf 1
[SwitchB-ospf-1] area 0
261
[SwitchB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[SwitchB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf 1
[SwitchC-ospf-1] import-route direct
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-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
Switch A, so that Switch B can obtain the route to 8.1.1.0/24.
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 3.1.1.1 as-number 65009
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 3.1.1.1 enable
[SwitchA-bgp-ipv4] network 8.1.1.0 24
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 3.1.1.2 as-number 65008
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 3.1.1.2 enable
4. Configure BGP and IGP route redistribution:
# Configure route redistribution between BGP and OSPF on Switch B.
[SwitchB-bgp-ipv4] import-route ospf 1
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
[SwitchB] ospf 1
[SwitchB-ospf-1] import-route bgp
[SwitchB-ospf-1] quit
# Display the BGP routing table on Switch A.
[SwitchA] 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
Origin: i - IGP, e - EGP, ? - incomplete
262
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?
# Display the OSPF routing table on Switch C.
[SwitchC] 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.
[SwitchA] 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
[SwitchC] 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
263
BGP route summarization configuration example
Network requirements
As shown in Figure 65 , run EBGP between Switch C and Switch 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:
ï‚¡
ï‚¡
Configure static routing between Switch A and Switch B.
Configure OSPF between Switch B and Switch C.
ï‚¡
Configure OSPF to redistribute static routes.
•
Configure route summarization on Switch 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
Switch D.
Figure 65 Network diagram
Internal network
AS 65106
Switch B
Core layer device
Vlan-int110
192.168.212.1/24
Vlan-int100
172.17.100.1/24
External network
AS 64631
Switch A
Distribution layer device
Loop0
1.1.1.1/32
Loop0
2.2.2.2/32
Vlan-int110
192.168.212.161/24
Vlan-int100
172.17.100.2/24
Loop0
3.3.3.3/32
Vlan-int200
10.220.2.16/24
Switch C
Boundary device
Loop0
4.4.4.4/32
Vlan-int200
10.220.2.217/24
Switch D
External network device
192.168.64.0/24 192.168.74.0/24 192.168.99.0/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure static routing between Switch A and Switch B:
# Configure a default route with the next hop 192.168.212.1 on Switch A.
<SwitchA> system-view
[SwitchA] 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 Switch B.
<SwitchB> system-view
[SwitchB] ip route-static 192.168.64.0 24 192.168.212.161
[SwitchB] ip route-static 192.168.74.0 24 192.168.212.161
[SwitchB] ip route-static 192.168.99.0 24 192.168.212.161
3. Configure OSPF between Switch B and Switch C and configure OSPF on Switch B to redistribute static routes:
# Configure OSPF to advertise the local network and enable OSPF to redistribute static routes on Switch B.
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
264
[SwitchB-ospf-1] import-route static
[SwitchB-ospf-1] quit
# Configure OSPF to advertise the local networks on Switch C.
[SwitchC] ospf
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 10.220.2.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
# Display the IP routing table on Switch C.
[SwitchC] 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 OSPF 150 1 172.17.100.1 Vlan100
192.168.74.0/24 OSPF 150 1 172.17.100.1 Vlan100
192.168.99.0/24 OSPF 150 1 172.17.100.1 Vlan100
OSPF Routing table Status : <Inactive>
Summary Count : 2
Destination/Mask Proto Pre Cost NextHop Interface
10.220.2.0/24 OSPF 10 1 10.220.2.16 Vlan200
172.17.100.0/24 OSPF 10 1 172.17.100.2 Vlan100
The output shows that Switch C has learned routes to 192.168.64.0/24, 192.168.99.0/24, and
192.168.64.0/18 through OSPF.
4. Configure BGP between Switch C and Switch D and configure BGP on Switch C to redistribute
OSPF routes:
# On Switch C, enable BGP, specify Switch D as an EBGP peer, and configure BGP to redistribute OSPF routes.
[SwitchC] bgp 65106
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 10.220.2.217 as-number 64631
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 10.220.2.217 enable
[SwitchC-bgp-ipv4] import-route ospf
# Enable BGP, and configure Switch C as an EBGP peer on Switch D.
[SwitchD] bgp 64631
[SwitchD-bgp] router-id 4.4.4.4
[SwitchD-bgp] peer 10.220.2.16 as-number 65106
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] peer 10.220.2.16 enable
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
265
# Display the IP routing table on Switch D.
[SwitchD] 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 Vlan200
192.168.74.0/24 BGP 255 1 10.220.2.16 Vlan200
192.168.99.0/24 BGP 255 1 10.220.2.16 Vlan200
BGP Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch D has learned routes to 192.168.64.0/24, 192.168.74.0/24, and
192.168.99.0/24 through BGP.
# Verify that Switch D can ping hosts on networks 192.168.74.0/24, 192.168.99.0/24, and
192.168.64.0/18. (Details not shown.)
5. Configure route summarization on Switch 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 on Switch C, and disable advertisement of specific routes.
[SwitchC-bgp-ipv4] aggregate 192.168.64.0 18 detail-suppressed
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
Verifying the configuration
# Display IP routing table on Switch C.
[SwitchC] 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 OSPF 150 1 172.17.100.1 Vlan100
192.168.74.0/24 OSPF 150 1 172.17.100.1 Vlan100
192.168.99.0/24 OSPF 150 1 172.17.100.1 Vlan100
The output shows that Switch C has a summary route 192.168.64.0/18 with the output interface
Null0.
# Display IP routing table on Switch D.
[SwitchD] display ip routing-table protocol bgp
Summary Count : 1
BGP Routing table Status : <Active>
Summary Count : 1
Destination/Mask Proto Pre Cost NextHop Interface
192.168.64.0/18 BGP 255 0 10.220.2.16 Vlan200
BGP Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch D has only one route 192.168.64.0/18 to AS 65106.
266
# Verify that Switch D can ping the hosts on networks 192.168.64.0/24, 192.168.74.0/24 and
192.168.99.0/24. (Details not shown.)
BGP load balancing configuration example
Network requirements
As shown in Figure 66 , run EBGP between Switch A and Switch B, and between Switch A and Switch
C. Run IBGP between Switch B and Switch C. Configure load balancing over the two EBGP links on
Switch A.
Figure 66 Network diagram
AS 65009
Loop0
2.2.2.2/32
Vlan-int100
8.1.1.1/24
AS 65008
Loop0
1.1.1.1/32
Vlan-int200
3.1.1.2/24
EBGP
Switch A
Vlan-int300
3.1.2.2/24 EBGP
Vlan-int200
3.1.1.1/24
Switch B
IBGP
Vlan-int400
9.1.1.1/24
Vlan-int400
9.1.1.2/24
Intranet
Vlan-int300
3.1.2.1/32
Switch C
Loop0
3.3.3.3/24
Requirements analysis
On Switch A:
•
Establish EBGP connections with Switch B and Switch C.
•
Configure BGP to advertise network 8.1.1.0/24 to Switch B and Switch C, so that Switch B and
Switch C can access the internal network connected to Switch A.
On Switch B:
•
Establish an EBGP connection with Switch A and an IBGP connection with Switch C.
•
Configure BGP to advertise network 9.1.1.0/24 to Switch A, so that Switch A can access the intranet through Switch B.
•
Configure a static route to interface loopback 0 on Switch C (or use a routing protocol like
OSPF) to establish the IBGP connection.
On Switch C:
•
Establish an EBGP connection with Switch A and an IBGP connection with Switch B.
•
Configure BGP to advertise network 9.1.1.0/24 to Switch A, so that Switch A can access the intranet through Switch C.
•
Configure a static route to interface loopback 0 on Switch B (or use another protocol like OSPF) to establish the IBGP connection.
Configure load balancing on Switch A.
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure BGP connections:
267
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 3.1.1.1 as-number 65009
[SwitchA-bgp] peer 3.1.2.1 as-number 65009
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 3.1.1.1 enable
[SwitchA-bgp-ipv4] peer 3.1.2.1 enable
[SwitchA-bgp-ipv4] network 8.1.1.0 24
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 3.1.1.2 as-number 65008
[SwitchB-bgp] peer 3.3.3.3 as-number 65009
[SwitchB-bgp] peer 3.3.3.3 connect-interface loopback 0
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 3.1.1.2 enable
[SwitchB-bgp-ipv4] peer 3.3.3.3 enable
[SwitchB-bgp-ipv4] network 9.1.1.0 24
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
[SwitchB] ip route-static 3.3.3.3 32 9.1.1.2
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 65009
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 3.1.2.2 as-number 65008
[SwitchC-bgp] peer 2.2.2.2 as-number 65009
[SwitchC-bgp] peer 2.2.2.2 connect-interface loopback 0
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 3.1.2.2 enable
[SwitchC-bgp-ipv4] peer 2.2.2.2 enable
[SwitchC-bgp-ipv4] network 9.1.1.0 24
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
[SwitchC] ip route-static 2.2.2.2 32 9.1.1.1
# Display the BGP routing table on Switch A.
[SwitchA] 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
268
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
ï‚¡ 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 it is the optimal route (because the ID of
Switch B is smaller). The route with next hop 3.1.2.1 is marked with an asterisk (*), indicating it is a valid route, but not the optimal route.
ï‚¡ By using the display ip routing-table command, you can find only one route to 9.1.1.0/24 with next hop 3.1.1.1 and output interface VLAN-interface 200.
3. Configure loading balancing:
Because Switch A has two routes to reach AS 65009, configuring load balancing over the two
BGP routes on Switch A can improve link usage.
# Configure Switch A.
[SwitchA] bgp 65008
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] balance 2
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
Verifying the configuration
# Display the BGP routing table on Switch A.
[SwitchA] 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
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 the route 9.1.1.0/24 has two next hops, 3.1.1.1 and 3.1.2.1, both of which are marked with a greater-than sign (>), indicating that they are the optimal routes.
The display ip routing-table command output shows two routes to 9.1.1.0/24. One has next hop
3.1.1.1 and output interface VLAN-interface 200, and the other has next hop 3.1.2.1 and output interface VLAN-interface 300.
269
BGP community configuration example
Network requirements
As shown in Figure 67 , Switch B establishes EBGP connections with Switch A and Switch C.
Configure NO_EXPORT community attribute on Switch A to make routes from AS 10 not advertised by AS 20 to any other AS.
Figure 67 Network diagram
Loop0
1.1.1.1/32
Vlan-int100
9.1.1.1/24
Vlan-int200
200.1.2.1/24
Switch A
AS 10
EBGP
Loop0
2.2.2.2/32
Vlan-int200
200.1.2.2/24
AS 20
Vlan-int300
Switch B
200.1.3.1/24
EBGP
Vlan-int300
200.1.3.2/24
Loop0
3.3.3.3/32
Switch C
AS 30
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure EBGP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 10
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 200.1.2.2 as-number 20
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 200.1.2.2 enable
[SwitchA-bgp-ipv4] network 9.1.1.0 255.255.255.0
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 20
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 200.1.2.1 as-number 10
[SwitchB-bgp] peer 200.1.3.2 as-number 30
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 200.1.2.1 enable
[SwitchB-bgp-ipv4] peer 200.1.3.2 enable
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 30
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 200.1.3.1 as-number 20
270
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 200.1.3.1 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Display the BGP routing table on Switch B.
[SwitchB] 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)
Relay nexthop : 200.1.2.1
Original nexthop: 200.1.2.1
OutLabel : NULL
AS-path : 10
Origin : igp
Attribute value : pref-val 0
State : valid, external, best,
# Display advertisement information of network 9.1.1.0 on Switch B.
[SwitchB] 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):
200.1.3.2
The output shows that Switch B can advertise the route with the destination 9.1.1.0/24 to other
ASs through BGP.
# Display the BGP routing table on Switch C.
[SwitchC] 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
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
The output shows that Switch C has learned route 9.1.1.0/24 from Switch B.
271
3. Configure BGP community:
# Configure a routing policy.
[SwitchA] route-policy comm_policy permit node 0
[SwitchA-route-policy-comm_policy-0] apply community no-export
[SwitchA-route-policy-comm_policy-0] quit
# Apply the routing policy.
[SwitchA] bgp 10
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 200.1.2.2 route-policy comm_policy export
[SwitchA-bgp-ipv4] peer 200.1.2.2 advertise-community
Verifying the configuration
# Display the routing table on Switch B.
[SwitchB] 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)
Relay nexthop : 200.1.2.1
Original nexthop: 200.1.2.1
OutLabel : NULL
Community : No-Export
AS-path : 10
Origin : igp
Attribute value : pref-val 0
State : valid, external, best,
# Display advertisement information for the route 9.1.1.0 on Switch B.
[SwitchB] 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 Switch C.
[SwitchC] display bgp routing-table ipv4
Total number of routes: 0
The output shows BGP has not learned any route.
272
BGP route reflector configuration example
Network requirements
As shown in Figure 68 , all switches run BGP. Run EBGP between Switch A and Switch B, and run
IBGP between Switch C and Switch B, and between Switch C and Switch D.
Configure Switch C as a route reflector with clients Switch B and Switch D to allow Switch D to learn route 20.0.0.0/8 from Switch C.
Figure 68 Network diagram
Vlan-int100
20.1.1.1/8
Loop0
1.1.1.1/32
Switch A
Vlan-int200
192.1.1.1/24
Loop0
3.3.3.3/32
Vlan-int300
193.1.1.1/24
Switch C
Route reflector
Vlan-int400
194.1.1.1/24
Vlan-int200
192.1.1.2/24
Loop0
2.2.2.2/32
Vlan-int300
193.1.1.2/24
Vlan-int400
194.1.1.2/24
Loop0
4.4.4.4/32
AS 100 Switch B AS 200 Switch D
Configuration procedure
1. Configure IP addresses for interfaces and configure OSPF in AS 200. (Details not shown.)
2. Configure BGP connections:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 100
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 192.1.1.2 as-number 200
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 192.1.1.2 enable
# Inject network 20.0.0.0/8 to the BGP routing table.
[SwitchA-bgp-ipv4] network 20.0.0.0
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 200
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 192.1.1.1 as-number 100
[SwitchB-bgp] peer 193.1.1.1 as-number 200
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 192.1.1.1 enable
[SwitchB-bgp-ipv4] peer 193.1.1.1 enable
[SwitchB-bgp-ipv4] peer 193.1.1.1 next-hop-local
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C.
273
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 193.1.1.2 as-number 200
[SwitchC-bgp] peer 194.1.1.2 as-number 200
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 193.1.1.2 enable
[SwitchC-bgp-ipv4] peer 194.1.1.2 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] bgp 200
[SwitchD-bgp] router-id 4.4.4.4
[SwitchD-bgp] peer 194.1.1.1 as-number 200
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] peer 194.1.1.1 enable
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
3. Configure Switch C as the route reflector.
[SwitchC] bgp 200
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 193.1.1.2 reflect-client
[SwitchC-bgp-ipv4] peer 194.1.1.2 reflect-client
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
Verifying the configuration
# Display the BGP routing table on Switch B.
[SwitchB] 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
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >e 20.0.0.0 192.1.1.1 0 0 100i
# Display the BGP routing table on Switch D.
[SwitchD] 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,
274
s - suppressed, S - stale, i - internal, e - external
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 20.0.0.0 193.1.1.2 0 100 0 100i
The output shows that Switch D has learned route 20.0.0.0/8 from Switch C.
BGP confederation configuration example
Network requirements
As shown in Figure 69 , split AS 200 into three sub-ASs (AS 65001, AS 65002, and AS 65003) to
reduce IBGP connections. Switches in AS65001 are fully meshed.
Figure 69 Network diagram
Switch F Switch B
Switch C
Vlan-int600
Vlan-int200
Vlan-int300
AS 65002
AS 65003
Vlan-int100
AS 100
-int
300
Switch D
Vlan-int100
Switch A
Vlan-int500
Vlan-int500
Vlan-int400
Vlan-int200
AS 65001
Vlan-int200
Switch E
AS 200
Table 15 Interface and IP address assignment
Device
Switch A
Switch B
Interface
Vlan-int100
Vlan-int200
Vlan-int300
Vlan-int400
Vlan-int500
Vlan-int200
IP address
200.1.1.1/24
10.1.1.1/24
10.1.2.1/24
10.1.3.1/24
10.1.4.1/24
10.1.1.2/24
Device
Switch D
Switch E
Switch F
Switch C
Configuration procedure
Vlan-int300 10.1.2.2/24
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure BGP confederation:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65001
[SwitchA-bgp] router-id 1.1.1.1
Interface
Vlan-int200
Vlan-int400
Vlan-int200
Vlan-int500
Vlan-int100
Vlan-int600
IP address
10.1.5.1/24
10.1.3.2/24
10.1.5.2/24
10.1.4.2/24
200.1.1.2/24
9.1.1.1/24
275
[SwitchA-bgp] confederation id 200
[SwitchA-bgp] confederation peer-as 65002 65003
[SwitchA-bgp] peer 10.1.1.2 as-number 65002
[SwitchA-bgp] peer 10.1.2.2 as-number 65003
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 10.1.1.2 enable
[SwitchA-bgp-ipv4] peer 10.1.2.2 enable
[SwitchA-bgp-ipv4] peer 10.1.1.2 next-hop-local
[SwitchA-bgp-ipv4] peer 10.1.2.2 next-hop-local
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65002
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] confederation id 200
[SwitchB-bgp] confederation peer-as 65001 65003
[SwitchB-bgp] peer 10.1.1.1 as-number 65001
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 10.1.1.1 enable
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 65003
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] confederation id 200
[SwitchC-bgp] confederation peer-as 65001 65002
[SwitchC-bgp] peer 10.1.2.1 as-number 65001
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 10.1.2.1 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
3. Configure IBGP connections in AS 65001:
# Configure Switch A.
[SwitchA] bgp 65001
[SwitchA-bgp] peer 10.1.3.2 as-number 65001
[SwitchA-bgp] peer 10.1.4.2 as-number 65001
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 10.1.3.2 enable
[SwitchA-bgp-ipv4] peer 10.1.4.2 enable
[SwitchA-bgp-ipv4] peer 10.1.3.2 next-hop-local
[SwitchA-bgp-ipv4] peer 10.1.4.2 next-hop-local
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] bgp 65001
276
[SwitchD-bgp] router-id 4.4.4.4
[SwitchD-bgp] confederation id 200
[SwitchD-bgp] peer 10.1.3.1 as-number 65001
[SwitchD-bgp] peer 10.1.5.2 as-number 65001
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] peer 10.1.3.1 enable
[SwitchD-bgp-ipv4] peer 10.1.5.2 enable
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
# Configure Switch E.
<SwitchE> system-view
[SwitchE] bgp 65001
[SwitchE-bgp] router-id 5.5.5.5
[SwitchE-bgp] confederation id 200
[SwitchE-bgp] peer 10.1.4.1 as-number 65001
[SwitchE-bgp] peer 10.1.5.1 as-number 65001
[SwitchE-bgp] address-family ipv4 unicast
[SwitchE-bgp-ipv4] peer 10.1.4.1 enable
[SwitchE-bgp-ipv4] peer 10.1.5.1 enable
[SwitchE-bgp-ipv4] quit
[SwitchE-bgp] quit
4. Configure the EBGP connection between AS 100 and AS 200:
# Configure Switch A.
[SwitchA] bgp 65001
[SwitchA-bgp] peer 200.1.1.2 as-number 100
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 200.1.1.2 enable
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch F.
<SwitchF> system-view
[SwitchF] bgp 100
[SwitchF-bgp] router-id 6.6.6.6
[SwitchF-bgp] peer 200.1.1.1 as-number 200
[SwitchF-bgp] address-family ipv4 unicast
[SwitchF-bgp-ipv4] peer 200.1.1.1 enable
[SwitchF-bgp-ipv4] network 9.1.1.0 255.255.255.0
[SwitchF-bgp-ipv4] quit
[SwitchF-bgp] quit
Verifying the configuration
# Display the routing table on Switch B.
[SwitchB] 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,
277
s - suppressed, S - stale, i - internal, e - external
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
[SwitchB] 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)
Relay nexthop : 10.1.1.1
Original nexthop: 10.1.1.1
OutLabel : NULL
AS-path : (65001) 100
Origin : igp
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State : valid, external-confed, best,
# Display the BGP routing table on Switch D.
[SwitchD] 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
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
[SwitchD] 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)
Relay nexthop : 10.1.3.1
Original nexthop: 10.1.3.1
OutLabel : NULL
278
AS-path : 100
Origin : igp
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State : valid, internal-confed, best,
The output shows the following:
•
Switch F can send route information to Switch B and Switch C through the confederation by establishing only an EBGP connection with Switch A.
•
Switch B and Switch D are in the same confederation, but belong to different sub-ASs. They obtain external route information from Switch A, and generate identical BGP route entries although they have no direct connection in between.
BGP path selection configuration example
Network requirements
As shown in Figure 70 , all switches run BGP.
•
EBGP runs between Switch A and Switch B, and between Switch A and Switch C.
•
IBGP runs between Switch B and Switch D, and between Switch D and Switch C. OSPF is the
IGP protocol in AS 200.
Configure routing policies, making Switch D use the route 1.0.0.0/8 from Switch C as the optimal.
Figure 70 Network diagram
AS 200
AS 100 Vlan-int100 Vlan-int300
Vlan-int101
Switch B
Vlan-int300
Vlan-int100
Vlan-int200
Switch A Vlan-int200
Switch C
Table 16 Interface and IP address assignment
Vlan-int400
Switch D
Vlan-int400
Device
Switch A
Switch B
Interface
Vlan-int101
Vlan-int100
Vlan-int200
Vlan-int100
IP address
1.0.0.1/8
192.1.1.1/24
193.1.1.1/24
192.1.1.2/24
Device
Switch D
Switch C
Vlan-int300 194.1.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF on Switch B, Switch C, and Switch D:
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ospf
Interface
Vlan-int400
Vlan-int300
Vlan-int400
Vlan-int200
279
IP address
195.1.1.1/24
194.1.1.1/24
195.1.1.2/24
193.1.1.2/24
[SwitchB-ospf] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 192.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] network 194.1.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ospf
[SwitchC-ospf] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 193.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] ospf
[SwitchD-ospf] area 0
[SwitchD-ospf-1-area-0.0.0.0] network 194.1.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] network 195.1.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] quit
[SwitchD-ospf-1] quit
3. Configure BGP connections:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 100
[SwitchA-bgp] peer 192.1.1.2 as-number 200
[SwitchA-bgp] peer 193.1.1.2 as-number 200
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 192.1.1.2 enable
[SwitchA-bgp-ipv4] peer 193.1.1.2 enable
# Inject network 1.0.0.0/8 to the BGP routing table on Switch A.
[SwitchA-bgp-ipv4] network 1.0.0.0 8
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch B.
[SwitchB] bgp 200
[SwitchB-bgp] peer 192.1.1.1 as-number 100
[SwitchB-bgp] peer 194.1.1.1 as-number 200
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 192.1.1.1 enable
[SwitchB-bgp-ipv4] peer 194.1.1.1 enable
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C.
[SwitchC] bgp 200
[SwitchC-bgp] peer 193.1.1.1 as-number 100
[SwitchC-bgp] peer 195.1.1.1 as-number 200
[SwitchC-bgp] address-family ipv4 unicast
280
[SwitchC-bgp-ipv4] peer 193.1.1.1 enable
[SwitchC-bgp-ipv4] peer 195.1.1.1 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Configure Switch D.
[SwitchD] bgp 200
[SwitchD-bgp] peer 194.1.1.2 as-number 200
[SwitchD-bgp] peer 195.1.1.2 as-number 200
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] peer 194.1.1.2 enable
[SwitchD-bgp-ipv4] peer 195.1.1.2 enable
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
4. Configure local preference for route 1.0.0.0/8, making Switch D give priority to the route learned from Switch C:
# Define an ACL numbered 2000 on Switch C, permitting route 1.0.0.0/8.
[SwitchC] acl number 2000
[SwitchC-acl-basic-2000] rule permit source 1.0.0.0 0.255.255.255
[SwitchC-acl-basic-2000] quit
# Configure a routing policy named localpref on Switch C, setting the local preference of route
1.0.0.0/8 to 200 (the default is 100).
[SwitchC] route-policy localpref permit node 10
[SwitchC-route-policy-localpref-10] if-match ip address acl 2000
[SwitchC-route-policy-localpref-10] apply local-preference 200
[SwitchC-route-policy-localpref-10] quit
# Apply routing policy localpref to routes from peer 193.1.1.1.
[SwitchC] bgp 200
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 193.1.1.1 route-policy localpref import
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Display the BGP routing table on Switch D.
[SwitchD] 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,
s - suppressed, S - stale, i - internal, e - external
Origin: i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
* >i 1.0.0.0 193.1.1.1 200 0 100i
* i 192.1.1.1 100 0 100i
The output shows that Route 1.0.0.0/8 learned from Switch C is the optimal.
281
BGP GR configuration example
Network requirements
As shown in Figure 71 , all switches run BGP. EBGP runs between Switch A and Switch B. IBGP runs
between Switch B and Switch C.
Enable GR capability for BGP so that the communication between Switch A and Switch C is not affected when an active/standby switchover occurs on Switch B.
Figure 71 Network diagram
AS 65008 AS 65009
Vlan-int100
8.1.1.1/8
Switch A
( GR helper )
Vlan-int200
200.1.1.2/24
Vlan-int200
200.1.1.1/24
Vlan-int400
9.1.1.1/24
Switch B
( GR restarter )
Vlan-int400
9.1.1.2/24
Switch C
( GR helper )
Configuration procedure
1. Configure Switch A:
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the EBGP connection.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 200.1.1.1 as-number 65009
# Enable GR capability for BGP.
[SwitchA-bgp] graceful-restart
# Inject network 8.0.0.0/8 to the BGP routing table.
[SwitchA-bgp] address-family ipv4
[SwitchA-bgp-ipv4] network 8.0.0.0
# Enable Switch A to exchange IPv4 unicast routing information with Switch B.
[SwitchA-bgp-ipv4] peer 200.1.1.1 enable
2. Configure Switch B:
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the EBGP connection.
<SwitchB> system-view
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 200.1.1.2 as-number 65008
# Configure the IBGP connection.
[SwitchB-bgp] peer 9.1.1.2 as-number 65009
# Enable GR capability for BGP.
[SwitchB-bgp] graceful-restart
# Inject networks 200.1.1.0/24 and 9.1.1.0/24 to the BGP routing table.
[SwitchB-bgp] address-family ipv4
[SwitchB-bgp-ipv4] network 200.1.1.0 24
[SwitchB-bgp-ipv4] network 9.1.1.0 24
# Enable Switch B to exchange IPv4 unicast routing information with Switch A and Switch C.
282
[SwitchB-bgp-ipv4] peer 200.1.1.2 enable
[SwitchB-bgp-ipv4] peer 9.1.1.2 enable
3. Configure Switch C:
# Configure IP addresses for interfaces. (Details not shown.)
# Configure the IBGP connection.
<SwitchC> system-view
[SwitchC] bgp 65009
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 9.1.1.1 as-number 65009
# Enable GR capability for BGP.
[SwitchC-bgp] graceful-restart
# Enable Switch C to exchange IPv4 unicast routing information with Switch B.
[SwitchC-bgp-ipv4] peer 9.1.1.1 enable
Verifying the configuration
Ping Switch C on Switch A. Meanwhile, perform an active/standby switchover on Switch B. The ping operation is successful during the whole switchover process.
BFD for BGP configuration example
Network requirements
As shown in Figure 72 , configure OSPF as the IGP in AS 200.
•
Establish two IBGP connections between Switch A and Switch C. When both paths operate correctly, Switch C uses the path Switch A<—>Switch B<—>Switch C to exchange packets 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 Switch A<—>Switch D<—>Switch C takes effect immediately.
Figure 72 Network diagram
AS 100 1.1.1.0/24
Switch B
Vlan-int100 Vlan-int101
Vlan-int100 Vlan-int101
Switch A
Vlan-int200
AS 200
Vlan-int201
Switch C
Vlan-int200
Switch D
Vlan-int201
AS 300
283
Table 17 Interface and IP address assignment
Device
Switch A
Switch B
Interface
Vlan-int100
Vlan-int200
Vlan-int100
IP address
3.0.1.1/24
2.0.1.1/24
3.0.1.2/24
Device
Switch C
Switch D
Interface
Vlan-int101
Vlan-int201
Vlan-int200
IP address
3.0.2.2/24
2.0.2.2/24
2.0.1.2/24
Vlan-int101 3.0.2.1/24 Vlan-int201 2.0.2.1/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF to make sure that Switch A and Switch C are reachable to each other. (Details not shown.)
3. Configure BGP on Switch A:
# Establish two IBGP connections to Switch C.
<SwitchA> system-view
[SwitchA] bgp 200
[SwitchA-bgp] peer 3.0.2.2 as-number 200
[SwitchA-bgp] peer 2.0.2.2 as-number 200
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 3.0.2.2 enable
[SwitchA-bgp-ipv4] peer 2.0.2.2 enable
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Create ACL 2000 to permit 1.1.1.0/24 to pass.
[SwitchA] acl number 2000
[SwitchA-acl-basic-2000] rule permit source 1.1.1.0 0.0.0.255
[SwitchA-acl-basic-2000] quit
# Create two route policies, apply_med_50 and apply_med_100 . Policy apply_med_50 sets the MED for route 1.1.1.0/24 to 50. Policy apply_med_100 sets that to 100.
[SwitchA] route-policy apply_med_50 permit node 10
[SwitchA-route-policy-apply_med_50-10] if-match ip address acl 2000
[SwitchA-route-policy-apply_med_50-10] apply cost 50
[SwitchA-route-policy-apply_med_50-10] quit
[SwitchA] route-policy apply_med_100 permit node 10
[SwitchA-route-policy-apply_med_100-10] if-match ip address acl 2000
[SwitchA-route-policy-apply_med_100-10] apply cost 100
[SwitchA-route-policy-apply_med_100-10] quit
# 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.
[SwitchA] bgp 200
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 3.0.2.2 route-policy apply_med_50 export
[SwitchA-bgp-ipv4] peer 2.0.2.2 route-policy apply_med_100 export
[SwitchA-bgp-ipv4] quit
# Enable BFD for peer 3.0.2.2.
[SwitchA-bgp] peer 3.0.2.2 bfd
[SwitchA-bgp] quit
284
4. Configure BGP on Switch C:
# Establish two IBGP connections to Switch A.
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC-bgp] peer 3.0.1.1 as-number 200
[SwitchC-bgp] peer 2.0.1.1 as-number 200
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 3.0.1.1 enable
[SwitchC-bgp-ipv4] peer 2.0.1.1 enable
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Enable BFD for peer 3.0.1.1.
[SwitchC-bgp] peer 3.0.1.1 bfd
[SwitchC-bgp] quit
[SwitchC] quit
Verifying the configuration
# Display detailed BFD session information on Switch C.
<SwitchC> display bfd session verbose
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv4 Session Working Under Ctrl 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
Diag Info: No Diagnostic
The output shows that a BFD session has been established between Switch A and Switch C.
# Display BGP peer information on Switch C.
<SwitchC> display bgp peer ipv4
BGP local router ID: 3.3.3.3
Local AS number: 200
Total number of peers: 2 Peers in established state: 2
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
285
The output shows that Switch C has established two BGP connections with Switch A, and both connections are in Established state.
# Display route 1.1.1.0/24 on Switch C.
<SwitchC> 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
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NBRID: 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
Tunnel ID: Invalid Interface: Vlan-interface101
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch C communicates with network 1.1.1.0/24 through the path Switch
C<—>Switch B<—>Switch A.
# Break down the path Switch C<—>Switch B<—>Switch A and then display route 1.1.1.0/24 on
Switch C.
<SwitchC> 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
Cost: 100 Preference: 255
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 0
NBRID: 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
Tunnel ID: Invalid Interface: Vlan-interface201
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch C communicates with network 1.1.1.0/24 through the path Switch
C<—>Switch D<—>Switch A.
286
BGP FRR configuration example
Network requirements
As shown in Figure 73 , configure BGP FRR so that when Link B fails, BGP uses Link A to forward
traffic.
Figure 73 Network diagram
Loop0
2.2.2.2/32
Vlan-int 100
10.1.1.2/24
Vlan-int 101
20.1.1.2/24
AS 200
Switch A
Vlan-int 100
10.1.1.1/24
Switch B
Link B
Vlan-int 101
20.1.1.4/24
Switch D
AS 100 Vlan-int 200
30.1.1.1/24
Vlan-int 200
30.1.1.3/24
Link A
Switch C
Vlan-int 201
40.1.1.3/24
Vlan-int 201
40.1.1.4/24
Loop0
3.3.3.3/32
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF in AS 200 to ensure connectivity among Switch B, Switch C and Switch D.
(Details not shown.)
3. Configure BGP connections:
# Configure Switch A to establish EBGP sessions with Switch B and Switch C, and advertise network 1.1.1.1/32.
<SwitchA> system-view
[SwitchA] bgp 100
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 10.1.1.2 as-number 200
[SwitchA-bgp] peer 30.1.1.3 as-number 200
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] peer 10.1.1.2 enable
[SwitchA-bgp-ipv4] peer 30.1.1.3 enable
[SwitchA-bgp-ipv4] network 1.1.1.1 32
# Configure Switch B to establish an EBGP session with Switch A, and an IBGP session with
Switch D.
<SwitchB> system-view
[SwitchB] bgp 200
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 10.1.1.1 as-number 100
[SwitchB-bgp] peer 4.4.4.4 as-number 200
[SwitchB-bgp] peer 4.4.4.4 connect-interface loopback 0
[SwitchB-bgp] address-family ipv4 unicast
[SwitchB-bgp-ipv4] peer 10.1.1.1 enable
287
[SwitchB-bgp-ipv4] peer 4.4.4.4 enable
[SwitchB-bgp-ipv4] peer 4.4.4.4 next-hop-local
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
# Configure Switch C to establish an EBGP session with Switch A, and an IBGP session with
Switch D.
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 30.1.1.1 as-number 100
[SwitchC-bgp] peer 4.4.4.4 as-number 200
[SwitchC-bgp] peer 4.4.4.4 connect-interface loopback 0
[SwitchC-bgp] address-family ipv4 unicast
[SwitchC-bgp-ipv4] peer 30.1.1.1 enable
[SwitchC-bgp-ipv4] peer 4.4.4.4 enable
[SwitchC-bgp-ipv4] peer 4.4.4.4 next-hop-local
[SwitchC-bgp-ipv4] quit
[SwitchC-bgp] quit
# Configure Switch D to establish IBGP sessions with Switch B and Switch C, and advertise network 4.4.4.4/32.
<SwitchD> system-view
[SwitchD] bgp 200
[SwitchD-bgp] router-id 4.4.4.4
[SwitchD-bgp] peer 2.2.2.2 as-number 200
[SwitchD-bgp] peer 2.2.2.2 connect-interface loopback 0
[SwitchD-bgp] peer 3.3.3.3 as-number 200
[SwitchD-bgp] peer 3.3.3.3 connect-interface loopback 0
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] peer 2.2.2.2 enable
[SwitchD-bgp-ipv4] peer 3.3.3.3 enable
[SwitchD-bgp-ipv4] network 4.4.4.4 32
4. Configure preferred values so Link B is used to forward traffic between Switch A and Switch D:
# Configure Switch A to set the preferred value to 100 for routes received from Switch B.
[SwitchA-bgp-ipv4] peer 10.1.1.2 preferred-value 100
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# Configure Switch D to set the preferred value to 100 for routes received from Switch B.
[SwitchD-bgp-ipv4] peer 2.2.2.2 preferred-value 100
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
5. Configure BGP FRR:
# On Switch A, configure the source address of BFD echo packets as 11.1.1.1.
[SwitchA] bfd echo-source-ip 11.1.1.1
# Create routing policy frr to set a backup next hop 30.1.1.3 (Switch C) for the route destined for
4.4.4.4/32.
[SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32
[SwitchA] route-policy frr permit node 10
[SwitchA-route-policy] if-match ip address prefix-list abc
288
[SwitchA-route-policy] apply fast-reroute backup-nexthop 30.1.1.3
[SwitchA-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[SwitchA] bgp 100
[SwitchA-bgp] address-family ipv4 unicast
[SwitchA-bgp-ipv4] fast-reroute route-policy frr
[SwitchA-bgp-ipv4] quit
[SwitchA-bgp] quit
# On Switch D, configure the source address of BFD echo packets as 44.1.1.1.
[SwitchD] bfd echo-source-ip 44.1.1.1
# Create routing policy frr to set a backup next hop 3.3.3.3 (Switch C) for the route destined for
1.1.1.1/32.
[SwitchD] ip prefix-list abc index 10 permit 1.1.1.1 32
[SwitchD] route-policy frr permit node 10
[SwitchD-route-policy] if-match ip address prefix-list abc
[SwitchD-route-policy] apply fast-reroute backup-nexthop 3.3.3.3
[SwitchD-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[SwitchD] bgp 200
[SwitchD-bgp] address-family ipv4 unicast
[SwitchD-bgp-ipv4] fast-reroute route-policy frr
[SwitchD-bgp-ipv4] quit
[SwitchD-bgp] quit
Verifying the configuration
# Display detailed information about the route to 4.4.4.4/32 on Switch A. The output shows the backup next hop for the route.
[SwitchA] 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
Tunnel ID: Invalid Interface: Vlan-interface 100
BkTunnel ID: Invalid BkInterface: Vlan-interface 200
FtnIndex: 0x0
# Display detailed information about the route to 1.1.1.1/32 on Switch D. The output shows the backup next hop for the route.
289
[SwitchD] 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
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
Tunnel ID: Invalid Interface: Vlan-interface 101
BkTunnel ID: Invalid BkInterface: Vlan-interface 201
FtnIndex: 0x0
IPv6 BGP configuration examples
IPv6 BGP basic configuration example
Network requirements
As shown in Figure 74 , all switches run BGP. Run EBGP between Switch A and Switch B, and run
IBGP between Switch B and Switch C to allow Switch C to access network 50::/64 connected to
Switch A.
Figure 74 Network diagram
Vlan-int50
50::1/64
Loop0
1.1.1.1/32
AS 65008
EBGP
AS 65009
Loop0
2.2.2.2/32
Vlan-int10
Switch A
10::2/64
Vlan-int10
10::1/64
Switch B
Vlan-int9
9::1/64
IBGP
Loop0
3.3.3.3/32
Vlan-int9
9::2/64
Switch C
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure IBGP:
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 9::2 as-number 65009
[SwitchB-bgp] address-family ipv6
290
[SwitchB-bgp-ipv6] peer 9::2 enable
[SwitchB-bgp-ipv6] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 65009
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 9::1 as-number 65009
[SwitchC-bgp] address-family ipv6
[SwitchC-bgp-ipv6] peer 9::1 enable
3. Configure EBGP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 10::1 as-number 65009
[SwitchA-bgp] address-family ipv6
[SwitchA-bgp-ipv6] peer 10::1 enable
# Configure Switch B.
[SwitchB-bgp] peer 10::2 as-number 65008
[SwitchB-bgp] address-family ipv6
[SwitchB-bgp-ipv6] peer 10::2 enable
4. Inject network routes to the BGP routing table:
# Configure Switch A.
[SwitchA-bgp-ipv6] network 10:: 64
[SwitchA-bgp-ipv6] network 50:: 64
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# Configure Switch B.
[SwitchB-bgp-ipv6] network 10:: 64
[SwitchB-bgp-ipv6] network 9:: 64
[SwitchB-bgp-ipv6] quit
[SwitchB-bgp] quit
# Configure Switch C.
[SwitchC-bgp-ipv6] network 9:: 64
[SwitchC-bgp-ipv6] quit
[SwitchC-bgp] quit
Verifying the configuration
# Display IPv6 BGP peer information on Switch B.
[SwitchB] 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
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
9::2 65009 41 43 0 1 00:29:00 Established
291
10::2 65008 38 38 0 2 00:27:20 Established
The output shows that Switch A and Switch B have established an EBGP connection, and Switch B and Switch C have established an IBGP connection.
# Display IPv6 BGP routing table information on Switch A.
[SwitchA] display bgp routing-table ipv6
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
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 Switch A has learned routing information of AS 65009.
# Display IPv6 BGP routing table information on Switch C.
[SwitchC] 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
Origin: i - IGP, e - EGP, ? - incomplete
* > Network : 9:: PrefixLen : 64
292
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: i
* 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 Switch C has learned the route 50::/64.
# Verify that Switch C can ping hosts on network 50::/64. (Details not shown.)
IPv6 BGP route reflector configuration example
Network requirements
As shown in Figure 75 , run EBGP between Switch A and Switch B, run IBGP between Switch C and
Switch B, and between Switch C and Switch D.
Configure Switch C as a route reflector with clients Switch B and Switch D.
Figure 75 Network diagram
Loop0
1.1.1.1/32
Vlan-int10
1::1/64
Switch A
Vlan-int100
100::1/96
AS 100
Vlan-int101
101::1/96
Vlan-int100
100::2/96
Loop0
2.2.2.2/32
Vlan-int101
101::2/96
Loop0
3.3.3.3/32
Switch C
Vlan-int102
102::1/96
Vlan-int102
102::2/96
AS 200
Loop0
4.4.4.4/32
Switch B Switch D
Configuration procedure
1. Configure IPv6 addresses for interfaces and IPv4 addresses for loopback interfaces. (Details not shown.)
293
2. Configure IBGP and EBGP connections and advertise network routes through IPv6 BGP:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 100
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 100::2 as-number 200
[SwitchA-bgp] address-family ipv6
[SwitchA-bgp-ipv6] peer 100::2 enable
[SwitchA-bgp-ipv6] network 1:: 64
[SwitchA-bgp-ipv6] network 100:: 96
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# Configure Switch B
<SwitchB> system-view
[SwitchB] bgp 200
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 100::1 as-number 100
[SwitchB-bgp] peer 101::1 as-number 200
[SwitchB-bgp] address-family ipv6
[SwitchB-bgp-ipv6] peer 100::1 enable
[SwitchB-bgp-ipv6] peer 101::1 enable
[SwitchB-bgp-ipv6] peer 101::1 next-hop-local
[SwitchB-bgp-ipv6] network 100:: 96
[SwitchB-bgp-ipv6] network 101:: 96
[SwitchB-bgp-ipv6] quit
[SwitchB-bgp] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 101::2 as-number 200
[SwitchC-bgp] peer 102::2 as-number 200
[SwitchC-bgp] address-family ipv6
[SwitchC-bgp-ipv6] peer 101::2 enable
[SwitchC-bgp-ipv6] peer 102::2 enable
[SwitchC-bgp-ipv6] network 101:: 96
[SwitchC-bgp-ipv6] network 102:: 96
# Configure Switch D.
<SwitchD> system-view
[SwitchD] bgp 200
[SwitchD-bgp] router-id 4.4.4.4
[SwitchD-bgp] peer 102::1 as-number 200
[SwitchD-bgp] address-family ipv6
[SwitchD-bgp-ipv6] peer 102::1 enable
[SwitchD-bgp-ipv6] network 102:: 96
3. Configure Switch C as a route reflector, and configure Switch B and Switch D as its clients.
[SwitchC-bgp-ipv6] peer 101::2 reflect-client
[SwitchC-bgp-ipv6] peer 102::2 reflect-client
294
[SwitchC-bgp-ipv6] quit
[SwitchC-bgp] quit
Verifying the configuration
# Execute the display bgp routing-table ipv6 command on Switch D.
[SwitchD] display bgp routing-table ipv6
Total number of routes: 5
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
Origin: i - IGP, e - EGP, ? - incomplete
* >i Network : 1:: PrefixLen : 64
NextHop : 101::2 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: 100i
* >i Network : 100:: PrefixLen : 96
NextHop : 101::2 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: i
* >i Network : 101:: PrefixLen : 96
NextHop : 102::1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: i
* > Network : 102:: PrefixLen : 96
NextHop : :: LocPrf :
PrefVal : 32768 OutLabel : NULL
MED : 0
Path/Ogn: i
* i Network : 102:: PrefixLen : 96
NextHop : 102::1 LocPrf : 100
PrefVal : 0 OutLabel : NULL
MED : 0
Path/Ogn: i
The output shows that Switch D has learned the network 1::/64 from Switch C through route reflection.
295
6PE configuration example
Network requirements
As shown in Figure 76 , 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 76 Network diagram
Loop0
1::1/128
Vlan-int10
10::2/64
PE 1
Vlan-int10
10::1/64
CE 1
Loop0
2.2.2.2/32
Vlan-int30
1.1.1.1/16
AS 65100
Vlan-int30
1.1.1.2/16
Loop0
3.3.3.3/32
IBGP
IPv4/MPLS network
PE 2
Vlan-int20
20::2/64
Loop0
4::4/128
Vlan-int20
20::1/64
CE 2
IPv6 network IPv6 network
Configuration procedure
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
# Enable MPLS and LDP on VLAN-interface 30.
[PE1] interface vlan-interface 30
[PE1-Vlan-interface30] mpls enable
[PE1-Vlan-interface30] mpls ldp enable
[PE1-Vlan-interface30] quit
# Configure IBGP, enable the peer's 6PE capabilities, and redistribute IPv6 direct and static routes.
[PE1] bgp 65100
[PE1-bgp] router-id 2.2.2.2
[PE1-bgp] peer 3.3.3.3 as-number 65100
[PE1-bgp] peer 3.3.3.3 connect-interface loopback 0
[PE1-bgp] address-family ipv6
[PE1-bgp-ipv6] import-route direct
[PE1-bgp-ipv6] import-route static
296
[PE1-bgp-ipv6] peer 3.3.3.3 enable
[PE1-bgp-ipv6] peer 3.3.3.3 label-route-capability
[PE1-bgp-ipv6] quit
[PE1-bgp] quit
# Configure a 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 VLAN-interface 30.
[PE2] interface vlan-interface 30
[PE2-Vlan-interface30] mpls enable
[PE2-Vlan-interface30] mpls ldp enable
[PE2-Vlan-interface30] quit
# Configure IBGP, enable the peer's 6PE capabilities, and redistribute IPv6 direct and static routes.
[PE2] bgp 65100
[PE2-bgp] router-id 3.3.3.3
[PE2-bgp] peer 2.2.2.2 as-number 65100
[PE2-bgp] peer 2.2.2.2 connect-interface loopback 0
[PE2-bgp] address-family ipv6
[PE2-bgp-ipv6] import-route direct
[PE2-bgp-ipv6] import-route static
[PE2-bgp-ipv6] peer 2.2.2.2 enable
[PE2-bgp-ipv6] peer 2.2.2.2 label-route-capability
[PE2-bgp-ipv6] quit
[PE2-bgp] 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 on CE 1, with PE 1 as the default next hop.
297
<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, and the output shows that each of them has two IPv6 network routes.
# Display the IPv6 BGP routing table 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
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
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: ?
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# Verify that CE 1 can ping the IPv6 address 4::4 (loopback interface address) of CE 2. (Details not shown.)
BFD for IPv6 BGP configuration example
Network requirements
As shown in Figure 77 , configure OSPFv3 as the IGP in AS 200.
•
Establish two IBGP connections between Switch A and Switch C. When both paths operate correctly, Switch C uses the path Switch A<—>Switch B<—>Switch 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 Switch A<—>Switch D<—>Switch C takes effect immediately.
Figure 77 Network diagram
AS 100 1200::0/64
Switch B
Vlan-int100 Vlan-int101
Vlan-int100 Vlan-int101
Switch A
Vlan-int200
AS 200
Vlan-int201
Switch C
AS 300
Vlan-int200
Switch D
Vlan-int201
Table 18 Interface and IP address assignment
Device
Switch A
Switch B
Interface
Vlan-int100
Vlan-int200
Vlan-int100
IP address
3000::1/64
2000::1/64
3000::2/64
Device
Switch C
Switch D
Interface
Vlan-int101
Vlan-int201
Vlan-int200
IP address
3001::3/64
2001::3/64
2000::2/64
Vlan-int101 3001::2/64 Vlan-int201 2001::2/64
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 so that Switch A and Switch C can reach each other. (Details not shown.)
3. Configure IPv6 BGP on Switch A:
# Establish two IBGP connections to Switch C.
<SwitchA> system-view
[SwitchA] bgp 200
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 3001::3 as-number 200
299
[SwitchA-bgp] peer 2001::3 as-number 200
[SwitchA-bgp] address-family ipv6
[SwitchA-bgp-ipv6] peer 3001::3 enable
[SwitchA-bgp-ipv6] peer 2001::3 enable
[SwitchA-bgp-ipv6] quit
# Create IPv6 ACL 2000 to permit 1200::0/64 to pass.
[SwitchA] acl ipv6 number 2000
[SwitchA-acl6-basic-2000] rule permit source 1200:: 64
[SwitchA-acl6-basic-2000] quit
# Create two route policies, apply_med_50 and apply_med_100 . Policy apply_med_50 sets the MED for route 1200::0/64 to 50. Policy apply_med_100 sets that to 100.
[SwitchA] route-policy apply_med_50 permit node 10
[SwitchA-route-policy-apply_med_50-10] if-match ipv6 address acl 2000
[SwitchA-route-policy-apply_med_50-10] apply cost 50
[SwitchA-route-policy-apply_med_50-10] quit
[SwitchA] route-policy apply_med_100 permit node 10
[SwitchA-route-policy-apply_med_100-10] if-match ipv6 address acl 2000
[SwitchA-route-policy-apply_med_100-10] apply cost 100
[SwitchA-route-policy-apply_med_100-10] quit
# Apply routing policy apply_med_50 to routes outgoing to peer 3001::3, and apply routing policy apply_med_100 to routes outgoing to peer 2001::3.
[SwitchA] bgp 200
[SwitchA-bgp] address-family ipv6 unicast
[SwitchA-bgp-ipv6] peer 3001::3 route-policy apply_med_50 export
[SwitchA-bgp-ipv6] peer 2001::3 route-policy apply_med_100 export
[SwitchA-bgp-ipv6] quit
# Enable BFD for peer 3001::3.
[SwitchA-bgp] peer 3001::3 bfd
[SwitchA-bgp] quit
4. Configure IPv6 BGP on Switch C:
# Establish two IBGP connections to Switch A.
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] peer 3000::1 as-number 200
[SwitchC-bgp] peer 2000::1 as-number 200
[SwitchC-bgp] address-family ipv6
[SwitchC-bgp-ipv6] peer 3000::1 enable
[SwitchC-bgp-ipv6] peer 2000::1 enable
[SwitchC-bgp-ipv6] quit
# Enable BFD for peer 3001::1.
[SwitchC-bgp] peer 3000::1 bfd
[SwitchC-bgp] quit
[SwitchC] quit
Verifying the configuration
# Display detailed BFD session information on Switch C.
<SwitchC> display bfd session verbose
300
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 Session Working Under Ctrl Mode:
Local Discr: 513 Remote Discr: 513
Source IP: 3001::3
Destination IP: 3000::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: BGP6
Diag Info: No Diagnostic
The output shows that a BFD session has been established between Switch A and Switch C.
# Display BGP peer information on Switch C.
<SwitchC> 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
Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State
2000::1 200 8 8 0 0 00:04:45 Established
3000::1 200 5 4 0 0 00:01:53 Established
The output shows that Switch C has established two BGP connections with Switch A, and both connections are in Established state.
# Display route 1200::0/64 on Switch C.
<SwitchC> display ipv6 routing-table 1200::0 64 verbose
Summary Count : 1
Destination: 1200::/64
Protocol: BGP4+ Process ID: 0
SubProtID: 0x1 Age: 00h01m07s
Cost: 50 Preference: 255
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NBRID: 0x25000001 LastAs: 0
AttrID: 0x1 Neighbor: 3000::1
Flags: 0x10060 OrigNextHop: 3000::1
Label: NULL RealNextHop: FE80::20C:29FF:FE4A:3873
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface101
301
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch C communicates with network 1200::0/64 through the path Switch
C<—>Switch B<—>Switch A.
# Break down the path Switch C<—>Switch B<—>Switch A and then display route 1200::0/64 on
Switch C.
<SwitchC> 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
Tag: 0 State: Active Adv
OrigTblID: 0x1 OrigVrf: default-vrf
TableID: 0xa OrigAs: 0
NBRID: 0x25000000 LastAs: 0
AttrID: 0x0 Neighbor: 2000::1
Flags: 0x10060 OrigNextHop: 2000::1
Label: NULL RealNextHop: FE80::20C:29FF:FE40:715
BkLabel: NULL BkNextHop: N/A
Tunnel ID: Invalid Interface: Vlan-interface201
BkTunnel ID: Invalid BkInterface: N/A
The output shows that Switch C communicates with network 1200::0/64 through the path Switch
C<—>Switch D<—>Switch A.
IPv6 BGP FRR configuration example
Network requirements
As shown in Figure 78 , configuring BGP FRR so that when Link B fails, BGP uses Link A to forward
traffic.
Figure 78 Network diagram
Loop0
2.2.2.2/32
Vlan-int100
3001::2/64
Vlan-int101
3002::1/64
AS 200
Switch A
Vlan-int100
3001::1/64
Switch B
Link B
Vlan-int101
3002::2/64
Switch D
Vlan-int201
2002::2/64
AS 100 Vlan-int200
2001::1/64
Vlan-int200
2001::2/64
Link A
Switch C
Vlan-int201
2002::1/64
Loop0
3.3.3.3/32
302
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 in AS 200 to ensure connectivity among Switch B, Switch C and Switch D.
(Details not shown.)
3. Configure BGP connections:
# Configure Switch A to establish EBGP sessions with Switch B and Switch C, and advertise network 1::/64.
<SwitchA> system-view
[SwitchA] bgp 100
[SwitchA] router-id 1.1.1.1
[SwitchA-bgp] peer 3001::2 as-number 200
[SwitchA-bgp] peer 2001::2 as-number 200
[SwitchA-bgp] address-family ipv6 unicast
[SwitchA-bgp-ipv6] peer 3001::2 enable
[SwitchA-bgp-ipv6] peer 2001::2 enable
[SwitchA-bgp-ipv6] network 1:: 64
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# Configure Switch B to establish an EBGP session with Switch A, and an IBGP session with
Switch D.
<SwitchB> system-view
[SwitchB] bgp 200
[SwitchB] router-id 2.2.2.2
[SwitchB-bgp] peer 3001::1 as-number 100
[SwitchB-bgp] peer 3002::2 as-number 200
[SwitchB-bgp] address-family ipv6 unicast
[SwitchB-bgp-ipv6] peer 3001::1 enable
[SwitchB-bgp-ipv6] peer 3002::2 enable
[SwitchB-bgp-ipv6] peer 3002::2 next-hop-local
[SwitchB-bgp-ipv6] quit
[SwitchB-bgp] quit
# Configure Switch C to establish an EBGP session with Switch A, and an IBGP session with
Switch D.
<SwitchC> system-view
[SwitchC] bgp 200
[SwitchC] router-id 3.3.3.3
[SwitchC-bgp] peer 2001::1 as-number 100
[SwitchC-bgp] peer 2002::2 as-number 200
[SwitchC-bgp] address-family ipv6 unicast
[SwitchC-bgp-ipv6] peer 2001::1 enable
[SwitchC-bgp-ipv6] peer 2002::2 enable
[SwitchC-bgp-ipv6] peer 2002::2 next-hop-local
[SwitchC-bgp-ipv6] quit
[SwitchC-bgp] quit
# Configure Switch D to establish IBGP sessions with Switch B and Switch C, and advertise network 4::/64.
<SwitchD> system-view
[SwitchD] bgp 200
303
[SwitchD-bgp] peer 3002::1 as-number 200
[SwitchD-bgp] peer 2002::1 as-number 200
[SwitchD-bgp] address-family ipv6 unicast
[SwitchD-bgp-ipv6] peer 3002::1 enable
[SwitchD-bgp-ipv6] peer 2002::1 enable
[SwitchD-bgp-ipv6] network 4:: 64
[SwitchD-bgp-ipv6] quit
[SwitchD-bgp] quit
4. Configure preferred values so Link B is used to forward traffic between Switch A and Switch D:
# Configure Switch A to set the preferred value to 100 for routes received from Switch B.
[SwitchA-bgp-ipv6] peer 3001::2 preferred-value 100
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# Configure Switch D to set the preferred value to 100 for routes received from Switch B.
[SwitchD-bgp-ipv6] peer 3002::1 preferred-value 100
[SwitchD-bgp-ipv6] quit
[SwitchD-bgp] quit
5. Configure BGP FRR:
# On Switch A, create routing policy frr to set a backup next hop 2001::2 (Switch C) for the route destined for 4::/64.
<SwitchA> system-view
[SwitchA] ipv6 prefix-list abc index 10 permit 4:: 64
[SwitchA] route-policy frr permit node 10
[SwitchA-route-policy] if-match ipv6 address prefix-list abc
[SwitchA-route-policy] apply ipv6 fast-reroute backup-nexthop 2001::2
[SwitchA-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv6 unicast address family.
[SwitchA] bgp 100
[SwitchA-bgp] address-family ipv6 unicast
[SwitchA-bgp-ipv6] fast-reroute route-policy frr
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# On Switch D, create routing policy frr to set a backup next hop 2002::1 (Switch C) for the route destined for 1::/64.
<SwitchD> system-view
[SwitchD] ipv6 prefix-list abc index 10 permit 1:: 64
[SwitchD] route-policy frr permit node 10
[SwitchD-route-policy] if-match ipv6 address prefix-list abc
[SwitchD-route-policy] apply ipv6 fast-reroute backup-nexthop 2002::1
[SwitchD-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv6 unicast address family.
[SwitchD] bgp 200
[SwitchD-bgp] address-family ipv6 unicast
[SwitchD-bgp-ipv6] fast-reroute route-policy frr
[SwitchD-bgp-ipv6] quit
[SwitchD-bgp] quit
304
Verifying the configuration
# Display detailed information about the route to 4::/64 on Switch A. The output shows the backup next hop for the route.
[SwitchA] 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
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
Tunnel ID: Invalid Interface: Vlan-interface 100
BkTunnel ID: Invalid BkInterface: Vlan-interface 200
FtnIndex: 0x0
# Display detailed information about the route to 1::/64 on Switch D. The output shows the backup next hop for the route.
[SwitchD] 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
Tunnel ID: Invalid Interface: Vlan-interface 101
BkTunnel ID: Invalid BkInterface: Vlan-interface 201
FtnIndex: 0x0
305
IPsec for IPv6 BGP packets configuration example
Network requirements
As shown in Figure 79 , all switches run IPv6 BGP. Establish an IBGP connection between Switch A
and Switch B. Establish an EBGP connection between Switch B and Switch C.
To enhance security, configure IPsec to protect IPv6 BGP packets.
Figure 79 Network diagram
AS 65008 AS 65009
Switch A
Vlan-int100
1::1/64
Vlan-int100
1::2/64
Switch B
Vlan-int200
3::1/64
Vlan-int200
3::2/64
Switch C
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Establish an IBGP connection between Switch A and Switch B:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 65008
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] group ibgp internal
[SwitchA-bgp] peer 1::2 group ibgp
[SwitchA-bgp] address-family ipv6 unicast
[SwitchA-bgp-ipv6] peer ibgp enable
[SwitchA-bgp-ipv6] quit
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65008
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] group ibgp internal
[SwitchB-bgp] peer 1::1 group ibgp
[SwitchB-bgp] address-family ipv6 unicast
[SwitchB-bgp-ipv6] peer ibgp enable
[SwitchB-bgp-ipv6] quit
3. Establish an EBGP connection between Switch B and Switch C:
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 65009
[SwitchC-bgp] router-id 3.3.3.3
[SwitchC-bgp] group ebgp external
[SwitchC-bgp] peer 3::1 as-number 65008
[SwitchC-bgp] peer 3::1 group ebgp
[SwitchC-bgp] address-family ipv6 unicast
[SwitchC-bgp-ipv6] peer ebgp enable
[SwitchC-bgp-ipv6] quit
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[SwitchC-bgp] quit
# Configure Switch B.
[SwitchB-bgp] group ebgp external
[SwitchB-bgp] peer 3::2 as-number 65009
[SwitchB-bgp] peer 3::2 group ebgp
[SwitchB-bgp] address-family ipv6 unicast
[SwitchB-bgp-ipv6] peer ebgp enable
[SwitchB-bgp-ipv6] quit
[SwitchB-bgp] quit
4. Configure IPsec transform sets and IPsec profiles:
# On Switch A, create an IPsec transform set named tran1 .
[SwitchA] ipsec transform-set tran1
# Set the encapsulation mode to transport mode.
[SwitchA-ipsec-transform-set-tran1] encapsulation-mode transport
# Set the security protocol to ESP, the encryption algorithm to DES, and authentication algorithm to SHA1.
[SwitchA-ipsec-transform-set-tran1] esp encryption-algorithm des
[SwitchA-ipsec-transform-set-tran1] esp authentication-algorithm sha1
[SwitchA-ipsec-transform-set-tran1] quit
# Create an IPsec profile named policy001 , and specify the manual mode for it.
[SwitchA] ipsec profile policy001 manual
# Reference IPsec transform set tran1 .
[SwitchA-ipsec-profile-policy001-manual] transform-set tran1
# Set the SPIs of the inbound and outbound SAs to 12345 .
[SwitchA-ipsec-profile-policy001-manual] sa spi outbound esp 12345
[SwitchA-ipsec-profile-policy001-manual] sa spi inbound esp 12345
# Set the keys for the inbound and outbound SAs using ESP to abcdefg .
[SwitchA-ipsec-profile-policy001-manual] sa string-key outbound esp simple abcdefg
[SwitchA-ipsec-profile-policy001-manual] sa string-key inbound esp simple abcdefg
[SwitchA-ipsec-profile-policy001-manual] quit
# On Switch B, create an IPsec transform set named tran1 .
[SwitchB] ipsec transform-set tran1
# Set the encapsulation mode to transport mode.
[SwitchB-ipsec-transform-set-tran1] encapsulation-mode transport
# Set the security protocol to ESP, the encryption algorithm to DES, and authentication algorithm to SHA1.
[SwitchB-ipsec-transform-set-tran1] esp encryption-algorithm des
[SwitchB-ipsec-transform-set-tran1] esp authentication-algorithm sha1
[SwitchB-ipsec-transform-set-tran1] quit
# Create IPsec profile named policy001 , and specify the manual mode for it.
[SwitchB] ipsec profile policy001 manual
# Reference IPsec transform set tran1 .
[SwitchB-ipsec-profile-policy001-manual] transform-set tran1
# Set the SPIs of the inbound and outbound SAs to 12345 .
[SwitchB-ipsec-profile-policy001-manual] sa spi outbound esp 12345
[SwitchB-ipsec-profile-policy001-manual] sa spi inbound esp 12345
# Set the keys for the inbound and outbound SAs using ESP to abcdefg .
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[SwitchB-ipsec-profile-policy001-manual] sa string-key outbound esp simple abcdefg
[SwitchB-ipsec-profile-policy001-manual] sa string-key inbound esp simple abcdefg
[SwitchB-ipsec-profile-policy001-manual] quit
# Create an IPsec transform set named tran2 .
[SwitchB] ipsec transform-set tran2
# Set the encapsulation mode to transport mode.
[SwitchB-ipsec-transform-set-tran2] encapsulation-mode transport
# Set the security protocol to ESP, the encryption algorithm to DES, and authentication algorithm to SHA1.
[SwitchB-ipsec-transform-set-tran2] esp encryption-algorithm des
[SwitchB-ipsec-transform-set-tran2] esp authentication-algorithm sha1
[SwitchB-ipsec-transform-set-tran2] quit
# Create IPsec profile named policy002 , and specify the manual mode for it.
[SwitchB] ipsec profile policy002 manual
# Reference IPsec transform set tran2 .
[SwitchB-ipsec-profile-policy002-manual] transform-set tran2
# Set the SPIs of the inbound and outbound SAs to 54321 .
[SwitchB-ipsec-profile-policy002-manual] sa spi outbound esp 54321
[SwitchB-ipsec-profile-policy002-manual] sa spi inbound esp 54321
# Set the keys for the inbound and outbound SAs using ESP to gfedcba .
[SwitchB-ipsec-profile-policy002-manual] sa string-key outbound esp simple gfedcba
[SwitchB-ipsec-profile-policy002-manual] sa string-key inbound esp simple gfedcba
[SwitchB-ipsec-profile-policy002-manual] quit
# On Switch C, create an IPsec transform set named tran2 .
[SwitchC] ipsec transform-set tran2
# Set the encapsulation mode to transport mode.
[SwitchC-ipsec-transform-set-tran2] encapsulation-mode transport
# Set the security protocol to ESP, the encryption algorithm to DES, and authentication algorithm to SHA1.
[SwitchC-ipsec-transform-set-tran2] esp encryption-algorithm des
[SwitchC-ipsec-transform-set-tran2] esp authentication-algorithm sha1
[SwitchC-ipsec-transform-set-tran2] quit
# Create IPsec profile named policy002 , and specify the manual mode for it.
[SwitchC] ipsec profile policy002 manual
# Reference IPsec transform set tran2 .
[SwitchC-ipsec-profile-policy002-manual] transform-set tran2
# Set the SPIs of the inbound and outbound SAs to 54321 .
[SwitchC-ipsec-profile-policy002-manual] sa spi outbound esp 54321
[SwitchC-ipsec-profile-policy002-manual] sa spi inbound esp 54321
# Set the keys for the inbound and outbound SAs using ESP to gfedcba .
[SwitchC-ipsec-profile-policy002-manual] sa string-key outbound esp simple gfedcba
[SwitchC-ipsec-profile-policy002-manual] sa string-key inbound esp simple gfedcba
[SwitchC-ipsec-profile-policy002-manual] quit
5. Configure IPsec to protect IPv6 BGP packets between Switch A and Switch B:
# Configure Switch A.
[SwitchA] bgp 65008
[SwitchA-bgp] peer 1::2 ipsec-profile policy001
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[SwitchA-bgp] quit
# Configure Switch B.
[SwitchB] bgp 65008
[SwitchB-bgp] peer 1::1 ipsec-profile policy001
[SwitchB-bgp] quit
6. Configure IPsec to protect IPv6 BGP packets between Router B and Switch C:
# Configure Switch C.
[SwitchC] bgp 65009
[SwitchC-bgp] peer ebgp ipsec-profile policy002
[SwitchC-bgp] quit
# Configure Switch B.
[SwitchB] bgp 65008
[SwitchB-bgp] peer ebgp ipsec-profile policy002
[SwitchB-bgp] quit
Verifying the configuration
# Display detailed information about IPv6 BGP peers on Switch B.
[SwitchB] display bgp peer ipv6 verbose
Peer: 1::1 Local: 2.2.2.2
Type: IBGP link
BGP version 4, remote router ID 1.1.1.1
BGP current state: Established, Up for 00h05m54s
BGP current event: KATimerExpired
BGP last state: OpenConfirm
Port: Local - 24896 Remote - 179
Configured: Active Hold Time: 180 sec Keepalive Time: 60 sec
Received : Active Hold Time: 180 sec
Negotiated: Active Hold Time: 180 sec Keepalive Time: 60 sec
Peer optional capabilities:
Peer support BGP multi-protocol extended
Peer support BGP route refresh capability
Peer support BGP route AS4 capability
Address family IPv6 Unicast: advertised and received
Received: Total 9 messages, Update messages 1
Sent: Total 9 messages, Update messages 1
Maximum allowed prefix number: 4294967295
Threshold: 75%
Minimum time between advertisements is 15 seconds
Optional capabilities:
Multi-protocol extended capability has been enabled
Route refresh capability has been enabled
Peer preferred value: 0
IPsec profile name: policy001
Routing policy configured:
No routing policy is configured
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Peer: 3::2 Local: 2.2.2.2
Type: EBGP link
BGP version 4, remote router ID 3.3.3.3
BGP current state: Established, Up for 00h05m00s
BGP current event: KATimerExpired
BGP last state: OpenConfirm
Port: Local - 24897 Remote - 179
Configured: Active Hold Time: 180 sec Keepalive Time: 60 sec
Received : Active Hold Time: 180 sec
Negotiated: Active Hold Time: 180 sec Keepalive Time: 60 sec
Peer optional capabilities:
Peer support BGP multi-protocol extended
Peer support BGP route refresh capability
Peer support BGP route AS4 capability
Address family IPv6 Unicast: advertised and received
Received: Total 8 messages, Update messages 1
Sent: Total 8 messages, Update messages 1
Maximum allowed prefix number: 4294967295
Threshold: 75%
Minimum time between advertisements is 30 seconds
Optional capabilities:
Multi-protocol extended capability has been enabled
Route refresh capability has been enabled
Peer preferred value: 0
IPsec profile name: policy002
Routing policy configured:
No routing policy is configured
The output shows that IBGP and EBGP peers are established and both sent and received IPv6 BGP packets are encapsulated by IPsec.
Troubleshooting BGP
Symptom
Display BGP peer information by using the display bgp peer ipv4 unicast or display bgp peer ipv6 unicast command. The state of the connection to a peer cannot become established.
Analysis
To become BGP peers, any two routers must establish a TCP connection using port 179 and exchange Open messages successfully.
Solution
1. To resolve the problem:
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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 address/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. Verify that a valid route to the peer is available. f. Use the ping command to verify the connectivity to the peer. g. Use the display tcp verbose or display ipv6 tcp verbose command to verify the TCP connection. h. Verify that no ACL rule is applied to disable TCP port 179.
2. If the problem persists, contact Hewlett Packard Enterprise Support.
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Configuring PBR
Overview
Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop for packets that match specific criteria such as ACLs.
A device forwards received packets using the following process:
1. The device uses PBR to forward matching packets.
2. If the packets do not match the PBR policy or the PBR-based forwarding fails, the device uses the routing table, excluding the default route, to forward the packets.
3. If the routing table-based forwarding fails, the device uses the default next hop or default output interface defined in PBR to forward packets.
4. If the default next hop or default output interface-based forwarding fails, the device uses the default route to forward packets.
PBR includes local PBR and interface PBR.
•
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
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.
•
A node has a match mode of permit or deny .
A policy matches nodes in priority order against packets. 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, it is forwarded according to the routing table. if-match clause
PBR supports the if-match acl clause to set an ACL match criterion. You can specify only one if-match acl clause for a node. apply clause
PBR supports the apply next-hop clause to set next hops for packets.
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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
Permit
•
If the node is configured with an apply clause, PBR executes the apply clause on the node. It does not match the packet against the next node.
•
If the node is configured with no apply clause, the packet is forwarded according to the routing table.
Deny
The packet is forwarded according to the routing table.
No.
PBR matches the packet against the next node.
A node that has no if-match clauses matches any packet.
PBR matches the packet against the next node.
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 next hop.
•
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 .
PBR configuration task list
Tasks at a glance
(Required.) Configuring a policy :
•
•
Configuring match criteria for a node
•
Configuring actions for a node
•
•
Configuring a policy
Creating a node
Step
1. Enter system view.
2. Create a node for a policy, and enter policy node view.
Command system-view policy-based-route policy-name
[ deny | permit ] node node-number
Remarks
N/A
By default, no policy node is created.
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Configuring match criteria for a node
Step
1. Enter system view.
2. Enter policy node view.
3. Configure an
ACL match criterion.
Command system-view
Remarks
N/A policy-based-route policy-name [ deny | permit ] node node-number
N/A if-match acl acl-number { acl-number | name acl-name }
By default, no ACL match criterion is configured.
NOTE:
An ACL match criterion uses the specified ACL to match packets regardless of the permit or deny action and the time range of the ACL. If the specified ACL does not exist, no packet can match the criterion.
Configuring actions for a node
Step
1. Enter system view.
2. Enter policy node view.
Command system-view policy-based-route policy-name [ deny | permit ] node node-number
Remarks
N/A
3. Set next hops. apply next-hop [ vpn-instance
vpn-instance-name ] { ip-address [ direct ]
[ track track-entry-number ] }&<1n >
N/A
By default, no next hop is specified.
You can specify multiple next hops for backup by executing this command once or multiple times.
You can specify a maximum of two next hops for a node.
Configuring PBR
Configuring local PBR
Configure PBR by applying a policy locally. PBR uses the policy to guide the forwarding of locally generated packets. The specified policy must already exist. Otherwise, the local PBR configuration fails.
You can apply only one policy locally. Before you apply a new policy, you must first remove the current policy.
Local PBR might affect local services, such as ping and Telnet. Do not configure local PBR unless doing so is required.
To configure local PBR:
Step
1. Enter system view.
Command system-view
Remarks
N/A
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Step
2. Apply a policy locally.
Command ip local policy-based-route policy-name
Remarks
By default, no policy is locally applied.
Configuring interface PBR
Configure PBR by applying a policy to an interface. PBR uses the policy to guide the forwarding of packets received on the interface. The specified policy must already exist. Otherwise, the interface
PBR configuration fails.
You can apply only one policy to an interface. Before you apply a new policy, you must first remove the current policy from the interface.
You can apply a policy to multiple interfaces.
To configure interface PBR:
Step
1. Enter system view.
2. Enter interface view.
Command system-view
3. Apply a policy to the interface. ip policy-based-route policy-name
Remarks
N/A interface interface-type interface-number N/A
By default, no policy is applied to the interface.
Displaying and maintaining PBR
Execute display commands in any view and reset commands in user view.
Task
Display PBR policy information.
Command display ip policy-based-route [ policy policy-name ] display ip policy-based-route setup Display PBR configuration.
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-number [ slot slot-number ] interface-type
Clear PBR statistics. reset ip policy-based-route statistics [ policy policy-name ]
PBR configuration examples
Packet type-based local PBR configuration example
Network requirements
As shown in Figure 80 , configure PBR on Switch A to forward all TCP packets to the next hop
1.1.2.2. Switch A forwards other packets according to the routing table.
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Figure 80 Network diagram
Switch A
Vlan-int10
1.1.2.1/24
Vlan-int10
1.1.2.2/24
Switch B
Vlan-int20
1.1.3.1/24
Vlan-int20
1.1.3.2/24
Switch C
Configuration procedure
1. Configure Switch A:
# Create VLAN 10 and VLAN 20.
<SwitchA> system-view
[SwitchA] vlan 10
[SwitchA-vlan10] quit
[SwitchA] vlan 20
[SwitchA-vlan20] quit
# Configure the IP addresses of VLAN-interface 10 and VLAN-interface 20.
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ip address 1.1.2.1 24
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 20
[SwitchA-Vlan-interface20] ip address 1.1.3.1 24
[SwitchA-Vlan-interface20] quit
# Configure ACL 3101 to match TCP packets.
[SwitchA] acl number 3101
[SwitchA-acl-adv-3101] rule permit tcp
[SwitchA-acl-adv-3101] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1.1.2.2.
[SwitchA] policy-based-route aaa permit node 5
[SwitchA-pbr-aaa-5] if-match acl 3101
[SwitchA-pbr-aaa-5] apply next-hop 1.1.2.2
[SwitchA-pbr-aaa-5] quit
# Configure local PBR by applying policy aaa to Switch A.
[SwitchA] ip local policy-based-route aaa
2. Configure Switch B:
# Create VLAN 10.
<SwitchB> system-view
[SwitchB] vlan 10
[SwitchB-vlan10] quit
# Configure the IP address of VLAN-interface 10.
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ip address 1.1.2.2 24
3. Configure Switch C:
# Create VLAN 20.
<SwitchC> system-view
[SwitchC] vlan 20
[SwitchC-vlan20] quit
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# Configure the IP address of VLAN-interface 20.
[SwitchC] interface vlan-interface 20
[SwitchC-Vlan-interface20] ip address 1.1.3.2 24
Verifying the configuration
# Telnet to Switch B on Switch A. The operation succeeds.
# Telnet to Switch C on Switch A. The operation fails.
# Ping Switch C from Switch A. The operation succeeds.
Telnet uses TCP and ping uses ICMP. The results show the following:
•
All TCP packets sent from Switch A are forwarded to the next hop 1.1.2.2.
•
Other packets are forwarded through VLAN-interface 20.
•
The local PBR configuration is effective.
Packet type-based interface PBR configuration example
Network requirements
As shown in Figure 81 , configure PBR on Switch A to forward all TCP packets received on
VLAN-interface 11 to the next hop 1.1.2.2. Switch A forwards other packets according to the routing table.
Figure 81 Network diagram
Switch B Switch C
Vlan-int10
1.1.2.2/24
Vlan-int20
1.1.3.2/24
Vlan-int10
1.1.2.1/24
Vlan-int20
1.1.3.1/24
Switch A
Vlan-int11
10.110.0.10/24
Subnet
10.110.0.0/24
Host A
10.110.0.20/24
Gateway: 10.110.0.10
Configuration procedure
Host B
1. Configure Switch A:
# Create VLAN 10 and VLAN 20.
<SwitchA> system-view
[SwitchA] vlan 10
[SwitchA-vlan10] quit
[SwitchA] vlan 20
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[SwitchA-vlan20] quit
# Configure the IP addresses of VLAN-interface 10 and VLAN-interface 20.
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ip address 1.1.2.1 24
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 20
[SwitchA-Vlan-interface20] ip address 1.1.3.1 24
[SwitchA-Vlan-interface20] quit
# Configure ACL 3101 to match TCP packets.
[SwitchA] acl number 3101
[SwitchA-acl-adv-3101] rule permit tcp
[SwitchA-acl-adv-3101] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1.1.2.2.
[SwitchA] policy-based-route aaa permit node 5
[SwitchA-pbr-aaa-5] if-match acl 3101
[SwitchA-pbr-aaa-5] apply next-hop 1.1.2.2
[SwitchA-pbr-aaa-5] quit
# Configure interface PBR by applying policy aaa to VLAN-interface 11.
[SwitchA] interface vlan-interface 11
[SwitchA-Vlan-interface11] ip address 10.110.0.10 24
[SwitchA-Vlan-interface11] ip policy-based-route aaa
[SwitchA-Vlan-interface11] quit
2. Configure Switch B:
# Create VLAN 10.
<SwitchB> system-view
[SwitchB] vlan 10
[SwitchB-vlan10] quit
# Configure the IP address of VLAN-interface 10.
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ip address 1.1.2.2 24
[SwitchB-Vlan-interface10] quit
# Configure a static route to subnet 10.110.0.0/24.
[SwitchB] ip route-static 10.110.0.0 24 1.1.2.1
3. Configure Switch C:
# Create VLAN 20.
<SwitchC> system-view
[SwitchC] vlan 20
[SwitchC-vlan20] quit
# Configure the IP address of VLAN-interface 20.
[SwitchC] interface vlan-interface 20
[SwitchC-Vlan-interface20] ip address 1.1.3.2 24
[SwitchC-Vlan-interface20] quit
# Configure a static route to subnet 10.110.0.0/24.
[SwitchC] ip route-static 10.110.0.0 24 1.1.3.1
Verifying the configuration
# Configure the IP address 10.110.0.20/24 for Host A, and specify its gateway address as
10.110.0.10.
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# On Host A, Telnet to Switch B that is directly connected to Switch A. The operation succeeds.
# On Host A, Telnet to Switch C that is directly connected to Switch A. The operation fails.
# Ping Switch C from Host A. The operation succeeds.
Telnet uses TCP and ping uses ICMP. The results show the following:
•
All TCP packets arriving on VLAN-interface 11 of Switch A are forwarded to next hop 1.1.2.2.
•
Other packets are forwarded through VLAN-interface 20.
•
The interface PBR configuration is effective.
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Configuring 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
Before you configure an IPv6 static route, complete the following tasks:
•
Configure parameters for the related interfaces.
•
Configure link layer attributes for the related interfaces.
•
Make sure the neighboring nodes can reach each other.
To configure an IPv6 static route:
Step
1. Enter system view.
2. Configure an IPv6 static route.
Command system-view
•
Method 1: 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-value ] [ tag tag-value ]
[ description description-text ]
•
Method 2: 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-value ] [ tag tag-value ] [ description description-text ]
Remarks
N/A
By default, no IPv6 static route is configured.
3. (Optional.) Configure the default preference for
IPv6 static routes. ipv6 route-static default-preference
default-preference-value
The default setting is
60.
4. (Optional.) Delete all IPv6 static routes, including the default route. delete ipv6 [ vpn-instance vpn-instance-name ] static-routes all
The undo ipv6 route-static command deletes one IPv6 static route.
Configuring 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. For more information about BFD, see High Availability Configuration Guide .
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IMPORTANT:
Enabling BFD for a flapping route could worsen the situation.
Bidirectional control mode
To use BFD bidirectional control detection between two devices, enable BFD control mode for each device's static route destined to the peer.
To configure a static route and enable BFD control mode, use one of the following methods:
•
Specify an output interface and a direct next hop.
•
Specify an indirect next hop and a specific BFD packet source address for the static route.
To configure BFD control mode for an IPv6 static route (direct next hop):
Step Command
1. Enter system view. system-view
2. Configure BFD control mode for an
IPv6 static route.
•
Method 1: ipv6 route-static ipv6-address prefix-length interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ]
[ tag tag-value ] [ description description-text ]
•
Method 2: ipv6 route-static vpn-instance s-vpn-instance-name ipv6-address prefix-length interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ]
[ tag tag-value ] [ description description-text ]
To configure BFD control mode for an IPv6 static route (indirect next hop):
Remarks
N/A
By default, BFD control mode for an
IPv6 static route is not configured.
Step Command
1. Enter system view. system-view
2. Configure BFD control mode for an
IPv6 static route.
•
Method 1: ipv6 route-static ipv6-address prefix-length
{ next-hop-address bfd control-packet bfd-source ipv6-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ipv6-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ]
•
Method 2: ipv6 route-static vpn-instance s-vpn-instance-name ipv6-address prefix-length { next-hop-address bfd control-packet bfd-source ipv6-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ipv6-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ]
Remarks
N/A
By default,
BFD control mode for an
IPv6 static route is not configured.
Single-hop echo mode
With BFD echo 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.
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IMPORTANT:
Do not use BFD for a static route with the output interface in spoofing state.
To configure BFD echo mode for an IPv6 static route:
Step Command
1. Enter system view. system-view
2. Configure the source address of echo packets.
bfd echo-source-ipv6 ipv6-address
Remarks
N/A
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 mode for an IPv6 static route.
•
Method 1: ipv6 route-static ipv6-address prefix-length interface-type
interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ]
[ description description-text ]
•
Method 2: ipv6 route-static vpn-instance s-vpn-instance-name ipv6-address prefix-length interface-type
interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ]
[ description description-text ]
By default, BFD echo mode for an IPv6 static route is not configured.
The next hop IPv6 address must be a global unicast address.
Displaying and maintaining IPv6 static routes
Execute display commands in any view.
Task
Display IPv6 static route information.
Command display ipv6 routing-table protocol static [ inactive | verbose ]
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
Basic IPv6 static route configuration example
Network requirements
As shown in Figure 82 , configure IPv6 static routes so that hosts can reach one another.
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Figure 82 Network diagram
Host B 2::2/64
Vlan-int400
2::1/64
Vlan-int200
4::2/64
Switch B
Vlan-int300
5::2/64
Vlan-int200
4::1/64
Vlan-int300
5::1/64
Host A 1::2/64
Vlan-int100
1::1/64
Switch A
Vlan-int500
Switch C
3::1/64
Host C 3::2/64
Configuration procedure
1. Configure the IPv6 addresses for all VLAN interfaces. (Details not shown.)
2. Configure IPv6 static routes:
# Configure a default IPv6 static route on Switch A.
<SwitchA> system-view
[SwitchA] ipv6 route-static :: 0 4::2
# Configure two IPv6 static routes on Switch B.
<SwitchB> system-view
[SwitchB] ipv6 route-static 1:: 64 4::1
[SwitchB] ipv6 route-static 3:: 64 5::1
# Configure a default IPv6 static route on Switch C.
<SwitchC> system-view
[SwitchC] ipv6 route-static :: 0 5::2
3. Configure the IPv6 addresses for all the 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 Switch A.
[SwitchA] 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 : Vlan-interface200 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
# Display the IPv6 static route information on Switch B.
[SwitchB] display ipv6 routing-table protocol static
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Summary Count : 2
Static Routing table Status : <Active>
Summary Count : 2
Destination: 1::/64 Protocol : Static
NextHop : 4::1 Preference: 60
Interface : Vlan-interface200 Cost : 0
Destination: 3::/64 Protocol : Static
NextHop : 5::1 Preference: 60
Interface : Vlan-interface300 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
# Use the ping command to test the reachability.
[SwitchA] ping ipv6 3::1
Ping6(104=40+8+56 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
BFD for IPv6 static routes configuration example (direct next hop)
Network requirements
•
Configure an IPv6 static route to subnet 120::/64 on Switch A.
•
Configure an IPv6 static route to subnet 121::/64 on Switch 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
Switch C.
When the link between Switch A and Switch B through the Layer 2 switch fails, BFD can detect the failure immediately, and Switch A and Switch B can communicate through Switch C.
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Figure 83 Network diagram
121::/64
Switch A L2 Switch
Vlan-int10 Vlan-int10
Switch B
120::/64
Vlan-int11 Vlan-int13
BFD
Vlan-int11 Vlan-int13
Switch C
Table 19 Interface and IP address assignment
Device
Switch A
Switch A
Switch B
Switch B
Switch C
Interface
Vlan-int10
Vlan-int11
Vlan-int10
Vlan-int13
Vlan-int11
IPv6 address
12::1/64
10::102/64
12::2/64
13::1/64
10::100/64
Switch C
Configuration procedure
Vlan-int13 13::2/64
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 static routes and BFD:
# Configure IPv6 static routes on Switch A and enable BFD control mode for the static route that traverses the Layer 2 switch.
<SwitchA> system-view
[SwitchA] interface vlan-interface 10
[SwitchA-vlan-interface10] bfd min-transmit-interval 500
[SwitchA-vlan-interface10] bfd min-receive-interval 500
[SwitchA-vlan-interface10] bfd detect-multiplier 9
[SwitchA-vlan-interface10] quit
[SwitchA] ipv6 route-static 120:: 64 vlan-interface 10 FE80::2E0:FCFF:FE58:123E bfd control-packet
[SwitchA] ipv6 route-static 120:: 64 10::100 preference 65
[SwitchA] quit
# Configure IPv6 static routes on Switch B and enable BFD control mode for the static route that traverses the Layer 2 switch.
<SwitchB> system-view
[SwitchB] interface vlan-interface 10
[SwitchB-vlan-interface10] bfd min-transmit-interval 500
[SwitchB-vlan-interface10] bfd min-receive-interval 500
[SwitchB-vlan-interface10] bfd detect-multiplier 9
[SwitchB-vlan-interface10] quit
[SwitchB] ipv6 route-static 121:: 64 vlan-interface 10 FE80::2A0:FCFF:FE00:580A bfd control-packet
[SwitchB] ipv6 route-static 121:: 64 vlan-interface 13 13::2 preference 65
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[SwitchB] quit
# Configure IPv6 static routes on Switch C.
<SwitchC> system-view
[SwitchC] ipv6 route-static 120:: 64 13::1
[SwitchC] ipv6 route-static 121:: 64 10::102
Verifying the configuration
# Display the BFD sessions on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 Session Working Under Ctrl Mode:
Local Discr: 513 Remote Discr: 33
Source IP: FE80::2A0:FCFF:FE00:580A (link-local address of VLAN-interface 10 on
Switch A)
Destination IP: FE80::2E0:FCFF:FE58:123E (link-local address of VLAN-interface 10 on
Switch B)
Session State: Up Interface: Vlan10
Hold Time: 2012ms
The output shows that the BFD session has been created.
# Display IPv6 static routes on Switch A.
<SwitchA> 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 : Vlan10 Cost : 0
Direct Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 10. The link over VLAN-interface 10 fails.
# Display IPv6 static routes on Switch A again.
<SwitchA> 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
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Interface : Vlan11 Cost : 0
Static Routing table Status : < Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
BFD for IPv6 static routes configuration example (indirect next hop)
Network requirements
•
Switch A has a route to interface Loopback 1 (2::9/128) on Switch B, and the output interface is
VLAN-interface 10.
•
Switch B has a route to interface Loopback 1 (1::9/128) on Switch A, and the output interface is
VLAN-interface 12.
•
Switch D has a route to 1::9/128, and the output interface is VLAN-interface 10. It also has a route to 2::9/128, and the output interface is VLAN-interface 12.
Configure the following:
•
Configure an IPv6 static route to subnet 120::/64 on Switch A.
•
Configure an IPv6 static route to subnet 121::/64 on Switch 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 Switch C and Switch D.
When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately and Switch A and Switch B can communicate through Switch C.
Figure 84 Network diagram
121::/64
Loop1
1::9/128
Loop1
2::9/128
Switch D
Vlan-int10
Switch A
Vlan
-int
11
Vlan-int10
BFD
Vlan-int12
Vlan-int12
Vlan
-int
13
Switch B
120::/64
Vlan-int11 Vlan-int13
Switch C
Table 20 Interface and IP address assignment
Device
Switch A
Switch A
Switch A
Switch B
Switch B
Interface
Vlan-int10
Vlan-int11
Loop1
Vlan-int12
Vlan-int13
IPv6 address
12::1/64
10::102/64
1::9/128
11::2/64
13::1/64
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Device
Switch B
Switch C
Switch C
Switch D
Interface
Loop1
Vlan-int11
Vlan-int13
Vlan-int10
IPv6 address
2::9/128
10::100/64
13::2/64
12::2/64
Switch D Vlan-int12 11::1/64
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 static routes and BFD:
# Configure IPv6 static routes on Switch A and enable BFD control packet mode for the IPv6 static route that traverses Switch D.
<SwitchA> system-view
[SwitchA] bfd multi-hop min-transmit-interval 500
[SwitchA] bfd multi-hop min-receive-interval 500
[SwitchA] bfd multi-hop detect-multiplier 9
[SwitchA] ipv6 route-static 120:: 64 2::9 bfd control-packet bfd-source 1::9
[SwitchA] ipv6 route-static 120:: 64 10::100 preference 65
[SwitchA] quit
# Configure IPv6 static routes on Switch B and enable BFD control packet mode for the static route that traverses Switch D.
<SwitchB> system-view
[SwitchB] bfd multi-hop min-transmit-interval 500
[SwitchB] bfd multi-hop min-receive-interval 500
[SwitchB] bfd multi-hop detect-multiplier 9
[SwitchB] ipv6 route-static 121:: 64 1::9 bfd control-packet bfd-source 2::9
[SwitchB] ipv6 route-static 121:: 64 13::2 preference 65
[SwitchB] quit
# Configure IPv6 static routes on Switch C.
<SwitchC> system-view
[SwitchC] ipv6 route-static 120:: 64 13::1
[SwitchC] ipv6 route-static 121:: 64 10::102
# Configure IPv6 static routes on Switch D.
<SwitchD> system-view
[SwitchD] ipv6 route-static 120:: 64 11::2
[SwitchD] ipv6 route-static 121:: 64 12::1
Verifying the configuration
# Display the BFD sessions on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Up Session Num: 1 Init Mode: Active
IPv6 Session Working Under Ctrl Mode:
Local Discr: 513 Remote Discr: 33
Source IP: FE80::1:1B49 (link-local address of Loopback1 on Switch A)
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Destination IP: FE80::1:1B49 (link-local address of Loopback1 on Switch B)
Session State: Up Interface: N/A
Hold Time: 2012ms
The output shows that the BFD session has been created.
# Display the IPv6 static routes on Switch A.
<SwitchA> 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 : Vlan10 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates Switch B through VLAN-interface 10. The link over
VLAN-interface 10 fails.
# Display IPv6 static routes on Switch A again.
<SwitchA> 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 : Vlan11 Cost : 0
Static Routing table Status : <Inactive>
Summary Count : 0
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
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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 an IPv6 static route ."
•
Some dynamic routing protocols, such as OSPFv3, IPv6 IS-IS, and RIPng, 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.
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Configuring RIPng
Overview
RIP next generation (RIPng) is an extension of RIP-2 for support of IPv6. Most RIP concepts are applicable to RIPng.
RIPng is a distance vector routing protocol. It employs UDP to exchange route information through port 521. 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.
By default, the routing update is sent every 30 seconds. If the router receives no routing updates from a neighbor within 180 seconds, the routes learned from the neighbor are considered unreachable. If no routing update is received within another 240 seconds, the router removes these routes from the routing table.
RIPng for IPv6 has the following differences from RIP:
•
UDP port number —RIPng uses UDP port 521 to send and receive routing information.
•
Multicast address —RIPng uses FF02::9 as the link-local-router multicast address.
•
Destination Prefix —128-bit destination address prefix.
•
Next hop —128-bit IPv6 address.
•
Source address —RIPng uses FE80::/10 as the link-local source address.
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
RIPng uses request and response packets to exchange 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:
ï‚¡
Whether the source IPv6 address is the link-local address.
ï‚¡ Whether the port number is correct.
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4. A response packet that fails the check is discarded.
Protocols and standards
•
RFC 2080, RIPng for IPv6
•
RFC 2081, RIPng Protocol Applicability Statement
RIPng configuration task list
Tasks at a glance
(Required.) Configuring basic RIPng
(Optional.) Configuring RIPng route control :
•
Configuring an additional routing metric
•
Configuring RIPng route summarization
•
•
Configuring received/redistributed route filtering
•
Configuring a preference for RIPng
•
Configuring RIPng route redistribution
(Optional.) Tuning and optimizing the RIPng network :
•
•
Configuring split horizon and poison reverse
•
Configuring zero field check on RIPng packets
•
Configuring the maximum number of ECMP routes
(Optional.) Configuring RIPng GR
(Optional.) Applying an IPsec profile
Configuring basic RIPng
Before you configure basic RIPng, configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
To configure basic RIPng:
Step
1. Enter system view.
2. Create a RIPng process and enter its view.
3. Return to system view.
4. Enter interface view.
Command system-view ripng [ process-id ]
[ vpn-instance vpn-instance-name ] quit interface interface-type interface-number
Remarks
N/A
By default, the RIPng process is not created.
N/A
N/A
5. Enable RIPng on the interface.
ripng process-id enable
By default, RIPng is disabled.
If RIPng is not enabled on an interface, the interface does not send or receive any RIPng route.
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Configuring RIPng route control
Before you configure RIPng, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
•
Configure basic RIPng.
Configuring an additional routing metric
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.
To configure an inbound or outbound additional routing metric:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Specify an inbound additional routing metric.
4. Specify an outbound additional routing metric.
ripng metricin value ripng metricout value
The default setting is 0.
The default setting is 1.
Configuring RIPng route summarization
Configure route summarization on an interface, so 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.
To configure RIPng route summarization:
Step
1. Enter system view.
2. Enter interface view.
3. Advertise a summary IPv6 prefix.
Command system-view interface interface-type interface-number
ripng summary-address ipv6-address prefix-length
Remarks
N/A
N/A
By default, the summary IPv6 prefix is not configured.
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Advertising a default route
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
3. Configure RIPng to advertise a default route. ripng default-route { only |
originate } [ cost cost ]
Remarks
N/A
N/A
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 is available in the local IPv6 routing table.
Configuring received/redistributed route filtering
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.
To configure a RIPng route filtering policy:
Step
1. Enter system view.
2. Enter RIPng view.
3. Configure a filter policy to filter received routes.
4. Configure a filter policy to filter redistributed routes.
Command system-view
Remarks
N/A ripng [ process-id ] [ vpn-instance vpn-instance-name ] filter-policy { acl6-number | prefix-list prefix-list-name } import
N/A
By default, RIPng does not filter received routes. filter-policy { acl6-number | prefix-list prefix-list-name } export [ protocol
[ process-id ] ]
By default, RIPng does not filter redistributed routes.
Configuring a preference for RIPng
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.
To configure a preference for RIPng:
Step
1. Enter system view.
Remarks
N/A
2. Enter RIPng view.
3. Configure a preference for
RIPng.
Command system-view ripng [ process-id ]
[ vpn-instance vpn-instance-name ]
preference [ route-policy route-policy-name ] value
N/A
The default setting is 100.
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Configuring RIPng route redistribution
Step
1. Enter system view.
2. Enter RIPng view.
3. Redistribute routes from other routing protocols.
Command system-view
Remarks
N/A ripng [ process-id ]
[ vpn-instance vpn-instance-name ] import-route protocol
[ process-id ] [ allow-ibgp ] [ cost cost | route-policy route-policy-name ] *
N/A
By default, RIPng does not redistribute routes from other routing protocols.
default cost cost
The default metric of redistributed routes is 0.
4. (Optional.) Configure a default routing metric for redistributed routes.
Tuning and optimizing the RIPng network
This section describes how to tune and optimize the performance of the RIPng network as well as applications under special network environments.
Before you tune and optimize the RIPng network, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
•
Configure basic RIPng.
Configuring RIPng timers
You can adjust RIPng timers to optimize the performance of the RIPng network.
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.
To configure RIPng timers:
Step Command
1. Enter system view. system-view
2. Enter RIPng view.
3. Set RIPng timers.
Remarks
N/A ripng [ process-id ]
[ vpn-instance vpn-instance-name ]
N/A timers { garbage-collect garbage-collect-value |
suppress suppress-value |
timeout timeout-value | update update-value } *
By default:
•
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.
Configuring split horizon and poison reverse
If both split horizon and poison reverse are configured, only the poison reverse function takes effect.
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Configuring split horizon
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.
To configure split horizon:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Enable split horizon.
ripng split-horizon
By default, split horizon is enabled.
Configuring poison reverse
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.
To configure poison reverse:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Enable poison reverse.
ripng poison-reverse
By default, poison reverse is disabled.
Configuring zero field check on RIPng packets
Some fields in the RIPng packet header must be zero. These fields are called zero fields. You can enable zero field check on 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.
To configure RIPng zero field check:
Remarks
N/A
Step
1. Enter system view.
2. Enter RIPng view.
Command system-view ripng [ process-id ]
[ vpn-instance vpn-instance-name ]
3. Enable the zero field check on incoming RIPng packets. checkzero
N/A
By default, this feature is enabled.
Configuring the maximum number of ECMP routes
Step
1. Enter system view.
Command system-view
Remarks
N/A
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Step
2. Enter RIPng view.
3. Configure the maximum number of ECMP routes.
Command ripng [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A maximum load-balancing number
By default, the maximum number of RIPng ECMP routes equals the maximum number of ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of ECMP routes supported by the system.
For more information about the max-ecmp-num command, see
Layer 3—IP Routing Command
Reference.
Configuring RIPng 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.
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.
To configure GR on the GR restarter:
Remarks
N/A
Step
1. Enter system view.
2. Enable RIPng and enter
RIPng view.
Command system-view ripng [ process-id ]
[ vpn-instance vpn-instance-name ]
3. Enable the GR capability for
RIPng. graceful-restart
N/A
By default, RIPng GR is disabled.
Applying an IPsec profile
To protect routing information and prevent attacks, RIPng supports using an IPsec profile to authenticate protocol packets. For more information about IPsec profiles, see Security Configuration
Guide .
Outbound RIPng packets carry the Security Parameter Index (SPI) defined in the relevant IPsec profile. A device uses the SPI carried in a received packet to match against the configured IPsec
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profile. If they match, the device accepts the packet. If they do not match, the device discards the packet and does not establish a neighbor relationship with the sending device.
You can configure an IPsec profile for a RIPng process or interface. The IPsec profile configured for a process applies to all packets in the process. The IPsec profile configured for an interface applies to packets on the interface. If an interface and its process each have an IPsec profile configured, the interface uses its own IPsec profile.
To apply an IPsec profile to a process:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter RIPng view.
3. Apply an IPsec profile to the process. ripng [ process-id ] [ vpn-instance vpn-instance-name ]
N/A enable ipsec-profile profile-name
By default, no IPsec profile is applied.
To apply an IPsec profile to an interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Apply an IPsec profile to the interface. ripng ipsec-profile profile-name
By default, no IPsec profile is applied.
Displaying and maintaining RIPng
Execute display commands in any view and reset commands in user view.
Task
Display configuration information for a
RIPng process.
Command display ripng [ process-id ]
Display routes in the RIPng database.
Display routing information for a RIPng process.
Display RIPng interface information.
Reset a RIPng process.
Clear statistics for a RIPng process. display ripng process-id database [ ipv6-address prefix-length ] display ripng process-id route [ ipv6-address prefix-length
[ verbose ] | peer ipv6-address | statistics ]
display ripng process-id interface [ interface-type interface-number ] reset ripng process-id process reset ripng process-id statistics
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RIPng configuration examples
Basic RIPng configuration example
Network requirements
As shown in Figure 85 , Switch A, Switch B, and Switch C run RIPng. Configure Switch B to filter the
route 2::/64 learned from Switch A and to forward only the route 4::/64 to Switch A.
Figure 85 Network diagram
Vlan-int400
2::1/64
Switch A
Vlan-int100
1::1/64
Vlan-int100
1::2/64
Switch B
Vlan-int200
3::1/64
Vlan-int600
4::1/64
Vlan-int500
5::1/64
Vlan-int200
3::2/64
Switch C
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic RIPng:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ripng 1
[SwitchA-ripng-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ripng 1 enable
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 400
[SwitchA-Vlan-interface400] ripng 1 enable
[SwitchA-Vlan-interface400] quit
# Configure Switch B.
<SwitchA> system-view
[SwitchA] ripng 1
[SwitchA-ripng-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ripng 1 enable
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 400
[SwitchA-Vlan-interface400] ripng 1 enable
[SwitchA-Vlan-interface400] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ripng 1
[SwitchC-ripng-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] ripng 1 enable
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 500
[SwitchC-Vlan-interface500] ripng 1 enable
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[SwitchC-Vlan-interface500] quit
[SwitchC] interface vlan-interface 600
[SwitchC-Vlan-interface600] ripng 1 enable
[SwitchC-Vlan-interface600] quit
# Display the RIPng routing table on Switch B.
[SwitchB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::20F:E2FF:FE23:82F5 on Vlan-interface100
Destination 1::/64,
via FE80::20F:E2FF:FE23:82F5, cost 1, tag 0, AOF, 6 secs
Destination 2::/64,
via FE80::20F:E2FF:FE23:82F5, cost 1, tag 0, AOF, 6 secs
Peer FE80::20F:E2FF:FE00:100 on Vlan-interface200
Destination 3::/64,
via FE80::20F:E2FF:FE00:100, cost 1, tag 0, AOF, 11 secs
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
# Display the RIPng routing table on Switch A.
[SwitchA] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::200:2FF:FE64:8904 on Vlan-interface100
Destination 1::/64,
via FE80::200:2FF:FE64:8904, cost 1, tag 0, AOF, 31 secs
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
3. Configure route filtering:
# Use IPv6 prefix lists on Switch B to filter received and redistributed routes.
[SwitchB] ipv6 prefix-list aaa permit 4:: 64
[SwitchB] ipv6 prefix-list bbb deny 2:: 64
[SwitchB] ipv6 prefix-list bbb permit :: 0 less-equal 128
[SwitchB] ripng 1
[SwitchB-ripng-1] filter-policy prefix-list aaa export
[SwitchB-ripng-1] filter-policy prefix-list bbb import
[SwitchB-ripng-1] quit
# Display RIPng routing tables on Switch B and Switch A.
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[SwitchB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::1:100 on Vlan-interface100
Destination 1::/64,
via FE80::2:100, cost 1, tag 0, AOF, 6 secs
Peer FE80::3:200 on Vlan-interface200
Destination 3::/64,
via FE80::2:200, cost 1, tag 0, AOF, 11 secs
Destination 4::/64,
via FE80::2:200, cost 1, tag 0, AOF, 11 secs
Destination 5::/64,
via FE80::2:200, cost 1, tag 0, AOF, 11 secs
[SwitchA] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect
O - Optimal, F - Flush to RIB
----------------------------------------------------------------
Peer FE80::2:100 on Vlan-interface100
Destination 4::/64,
via FE80::1:100, cost 2, tag 0, AOF, 2 secs
RIPng route redistribution configuration example
Network requirements
As shown in Figure 86 , Switch B communicates with Switch A through RIPng 100 and with Switch C
through RIPng 200.
Configure route redistribution on Switch B, so the two RIPng processes can redistribute routes from each other.
Figure 86 Network diagram
RIPng 100 RIPng 200
Vlan-int200
2::1/64
Switch A
Vlan-int100
1::1/64
Vlan-int100
1::2/64
Switch B
Vlan-int300
3::1/64
Vlan-int300
3::2/64
Switch C
Vlan-int400
4::1/64
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic RIPng:
# Enable RIPng 100 on Switch A.
<SwitchA> system-view
[SwitchA] ripng 100
[SwitchA-ripng-100] quit
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[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ripng 100 enable
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ripng 100 enable
[SwitchA-Vlan-interface200] quit
# Enable RIPng 100 and RIPng 200 on Switch B.
<SwitchB> system-view
[SwitchB] ripng 100
[SwitchB-ripng-100] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ripng 100 enable
[SwitchB-Vlan-interface100] quit
[SwitchB] ripng 200
[SwitchB-ripng-200] quit
[SwitchB] interface vlan-interface 300
[SwitchB-Vlan-interface300] ripng 200 enable
[SwitchB-Vlan-interface300] quit
# Enable RIPng 200 on Switch C.
<SwitchC> system-view
[SwitchC] ripng 200
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] ripng 200 enable
[SwitchC-Vlan-interface300] quit
[SwitchC] interface vlan-interface 400
[SwitchC-Vlan-interface400] ripng 200 enable
[SwitchC-Vlan-interface400] quit
# Display the routing table on Switch A.
[SwitchA] 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 : 1::1 Preference: 0
Interface : Vlan100 Cost : 0
Destination: 1::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 2::/64 Protocol : Direct
NextHop : 2::1 Preference: 0
Interface : Vlan200 Cost : 0
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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 Switch B.
[SwitchB] ripng 100
[SwitchB-ripng-100] import-route ripng 200
[SwitchB-ripng-100] quit
[SwitchB] ripng 200
[SwitchB-ripng-200] import-route ripng 100
[SwitchB-ripng-200] quit
# Display the routing table on Switch A.
[SwitchA] 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 : 1::1 Preference: 0
Interface : Vlan100 Cost : 0
Destination: 1::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 2::/64 Protocol : Direct
NextHop : 2::1 Preference: 0
Interface : Vlan200 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 : Vlan100 Cost : 1
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Destination: FE80::/10 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
Destination: FF00::/8 Protocol : Direct
NextHop : :: Preference: 0
Interface : NULL0 Cost : 0
RIPng IPsec profile configuration example
Network requirements
As shown in Figure 87 , configure RIPng on the switches, and configure IPsec profiles on the
switches to authenticate and encrypt protocol packets.
Figure 87 Network diagram
Switch A
Vlan-int100
1::1/64
Vlan-int100
1::2/64
Switch B
Vlan-int200
3::1/64
Vlan-int200
3::2/64
Switch C
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure RIPng basic functions:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] ripng 1
[SwitchA-ripng-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ripng 1 enable
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] ripng 1
[SwitchB-ripng-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ripng 1 enable
[SwitchB-Vlan-interface200] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ripng 1 enable
[SwitchB-Vlan-interface100] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] ripng 1
[SwitchC-ripng-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] ripng 1 enable
[SwitchC-Vlan-interface200] quit
3. Configure RIPng IPsec profiles:
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On Switch A:
# Create an IPsec transform set named protrf1 .
[SwitchA] ipsec transform-set protrf1
# Specify the ESP encryption and authentication algorithms.
[SwitchA-ipsec-transform-set-protrf1] esp encryption-algorithm 3des-cbc
[SwitchA-ipsec-transform-set-protrf1] esp authentication-algorithm md5
# Specify the encapsulation mode as transport .
[SwitchA-ipsec-transform-set-protrf1] encapsulation-mode transport
[SwitchA-ipsec-transform-set-protrf1] quit
# Create a manual IPsec profile named profile001 .
[SwitchA] ipsec profile profile001 manual
# Reference IPsec transform set protrf1 .
[SwitchA-ipsec-profile-profile001-manual] transform-set protrf1
# Configure the inbound and outbound SPIs for ESP.
[SwitchA-ipsec-profile-profile001-manual] sa spi inbound esp 256
[SwitchA-ipsec-profile-profile001-manual] sa spi outbound esp 256
# Configure the inbound and outbound SA keys for ESP.
[SwitchA-ipsec-profile-profile001-manual] sa string-key inbound esp simple abc
[SwitchA-ipsec-profile-profile001-manual] sa string-key outbound esp simple abc
[SwitchA-ipsec-profile-profile001-manual] quit
On Switch B:
# Create an IPsec transform set named protrf1 .
[SwitchB] ipsec transform-set protrf1
# Specify the ESP encryption and authentication algorithms.
[SwitchB-ipsec-transform-set-protrf1] esp encryption-algorithm 3des-cbc
[SwitchB-ipsec-transform-set-protrf1] esp authentication-algorithm md5
# Specify the encapsulation mode as transport .
[SwitchB-ipsec-transform-set-protrf1] encapsulation-mode transport
[SwitchB-ipsec-transform-set-protrf1] quit
# Create a manual IPsec profile named profile001 .
[SwitchB] ipsec profile profile001 manual
# Reference IPsec transform set protrf1 .
[SwitchB-ipsec-profile-profile001-manual] transform-set protrf1
# Configure the inbound and outbound SPIs for ESP.
[SwitchB-ipsec-profile-profile001-manual] sa spi inbound esp 256
[SwitchB-ipsec-profile-profile001-manual] sa spi outbound esp 256
# Configure the inbound and outbound SA keys for ESP.
[SwitchB-ipsec-profile-profile001-manual] sa string-key inbound esp simple abc
[SwitchB-ipsec-profile-profile001-manual] sa string-key outbound esp simple abc
[SwitchB-ipsec-profile-profile001-manual] quit
On Switch C:
# Create an IPsec transform set named protrf1 .
[SwitchC] ipsec transform-set protrf1
# Specify the ESP encryption and authentication algorithms.
[SwitchC-ipsec-transform-set-protrf1] esp encryption-algorithm 3des-cbc
[SwitchC-ipsec-transform-set-protrf1] esp authentication-algorithm md5
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# Specify the encapsulation mode as transport .
[SwitchC-ipsec-transform-set-protrf1] encapsulation-mode transport
[SwitchC-ipsec-transform-set-protrf1] quit
# Create a manual IPsec profile named profile001 .
[SwitchC] ipsec profile profile001 manual
# Reference IPsec transform set protrf1 .
[SwitchC-ipsec-profile-profile001-manual] transform-set protrf1
# Configure the inbound and outbound SPIs for ESP.
[SwitchC-ipsec-profile-profile001-manual] sa spi inbound esp 256
[SwitchC-ipsec-profile-profile001-manual] sa spi outbound esp 256
# Configure the inbound and outbound SA keys for ESP.
[SwitchC-ipsec-profile-profile001-manual] sa string-key inbound esp simple abc
[SwitchC-ipsec-profile-profile001-manual] sa string-key outbound esp simple abc
[SwitchC-ipsec-profile-profile001-manual] quit
4. Apply the IPsec profiles to the RIPng process:
# Configure Switch A.
[SwitchA] ripng 1
[SwitchA-ripng-1] enable ipsec-profile profile001
[SwitchA-ripng-1] quit
# Configure Switch B.
[SwitchB] ripng 1
[SwitchB-ripng-1] enable ipsec-profile profile001
[SwitchB-ripng-1] quit
# Configure Switch C.
[SwitchC] ripng 1
[SwitchC-ripng-1] enable ipsec-profile profile001
[SwitchC-ripng-1] quit
Verifying the configuration
# Verify that RIPng packets between Switches A, B and C are protected by IPsec. (Details not shown.)
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Configuring OSPFv3
Overview
This chapter describes how to configure RFC 2740-compliant Open Shortest Path First version 3
(OSPFv3) for an IPv6 network. For more information about OSPFv2, see " Configuring OSPF ."
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.
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.
•
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.
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•
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 5340, OSPF for IPv6
•
RFC 2328, OSPF Version 2
•
RFC 3101, OSPF Not-So-Stubby Area (NSSA) Option
•
RFC 5187, OSPFv3 Graceful Restart
OSPFv3 configuration task list
Tasks at a glance
(Optional.) Configuring OSPFv3 area parameters :
•
•
•
Configuring an OSPFv3 virtual link
(Optional.) Configuring OSPFv3 network types :
•
Configuring the OSPFv3 network type for an interface
•
Configuring an NBMA or P2MP neighbor
(Optional.) Configuring OSPFv3 route control :
•
Configuring OSPFv3 route summarization
•
Configuring OSPFv3 received route filtering
•
Configuring Inter-Area-Prefix LSA filtering
•
Configuring an OSPFv3 cost for an interface
•
Configuring the maximum number of OSPFv3 ECMP routes
•
Configuring a preference for OSPFv3
•
Configuring OSPFv3 route redistribution
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Tasks at a glance
(Optional.) Tuning and optimizing OSPFv3 networks :
•
•
Specifying LSA transmission delay
•
Configuring a DR priority for an interface
•
Specifying SPF calculation interval
•
Specifying the LSA generation interval
•
Ignoring MTU check for DD packets
•
Disabling interfaces from receiving and sending OSPFv3 packets
•
Enabling the logging of neighbor state changes
•
Configuring OSPFv3 network management
•
Configuring the LSU transmit rate
•
•
Configuring prefix suppression
(Optional.) Configuring OSPFv3 GR :
•
•
•
(Optional.) Configuring OSPFv3 NSR
(Optional.) Configuring BFD for OSPFv3
(Optional.) Applying an IPsec profile
Enabling OSPFv3
Before you enable OSPFv3, configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
To enable an OSPFv3 process on a router:
•
Enable the OSPFv3 process globally.
•
Assign the OSPFv3 process a router ID.
•
Enable the OSPFv3 process on related interfaces.
The router ID uniquely identifies the router within an AS. If a router runs multiple OSPFv3 processes, you must specify a unique router ID for each process.
An OSPFv3 process ID has only local significance. Process 1 on a router can exchange packets with process 2 on another router.
To enable OSPFv3:
Step
1. Enter system view.
2. Enable an OSPFv3 process and enter its view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
By default, no OSPFv3 process is 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
N/A
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Step
5. Enable an OSPFv3 process on the interface.
Command
ospfv3 process-id area area-id
[ instance instance-id ]
Remarks
No OSPFv3 process is enabled on an interface by default.
Configuring OSPFv3 area parameters
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.
Configuration prerequisites
Before you configure OSPFv3 area parameters, enable OSPFv3.
Configuring a stub area
All the routers attached to a stub area must be configured with the stub command. The no-summary keyword is only available on the ABR of the stub area.
If you use the stub command with the no-summary keyword on an ABR, the ABR advertises a default route in an Inter-Area-Prefix LSA into the stub area. No AS External LSA, Inter-Area-Prefix
LSA, or other Inter-Area-Router LSA is advertised in the area. The stub area of this kind is called a totally stub area.
To configure an OSPFv3 stub area:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2.
3.
Enter OSPFv3 view.
Enter OSPFv3 area view.
4. Configure the area as a stub area. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
area area-id
N/A
N/A stub
[ default-route-advertise-always
| no-summary ] *
By default, no area is configured as a stub area.
5. (Optional.) Specify a cost for the default route advertised to the stub area. default-cost value The default setting is 1.
Configuring an NSSA area
To configure an NSSA area, configure the nssa command on all the routers attached to the area.
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To configure a totally NSSA area, configure the nssa no-summary command on the ABR. The ABR of a totally NSSA area does not advertise inter-area routes into the area.
To configure an NSSA area:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter OSPFv3 view.
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enter OSPFv3 area view.
area area-id
4.
5.
Configure the area as an
NSSA area.
(Optional.) Specify a cost for the default route advertised to the NSSA area.
default-cost cost
N/A
N/A nssa [ default-route-advertise
[ cost cost | 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.
The default setting is 1.
This command takes effect only on the ABR/ASBR of an NSSA or totally NSSA area.
Configuring an OSPFv3 virtual link
You can configure a virtual link to maintain connectivity between a non-backbone area and the backbone, or in the backbone itself.
IMPORTANT:
•
Both ends of a virtual link are ABRs that must be configured with the vlink-peer command.
•
Do not configure virtual links in the areas of a GR-capable process.
To configure a virtual link:
Step
1. Enter system view.
Command system-view
Remarks
N/A
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 | retransmit seconds | trans-delay seconds ] *
N/A
N/A
By default, no virtual link is configured.
Configuring OSPFv3 network types
OSPFv3 classifies networks into the following types by the link layer protocol:
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•
Broadcast — When the link layer protocol is Ethernet or FDDI, OSPFv3 considers the network type as broadcast by default.
•
NBMA — When the link layer protocol is ATM, Frame Relay, or X.25, OSPFv3 considers the network type as NBMA by default.
•
P2P — When the link layer protocol is PPP, LAPB, HDLC, or POS, OSPFv3 considers the network type as P2P by default.
Follow these guidelines when you change the network type of an OSPFv3 interface:
•
An NBMA network must be fully connected. Any two routers in the network must be directly reachable to each other through a virtual circuit. If no such direct link is available, you must change the network type through a command.
•
If direct connections are not available between some routers in an NBMA network, the type of interfaces associated must be configured as P2MP, or as P2P for interfaces with only one neighbor.
Configuration prerequisites
Before you configure OSPFv3 network types, enable OSPFv3.
Configuring the OSPFv3 network type for an interface
Step
1. Enter system view.
2. Enter interface view.
3. Configure a network type for the OSPFv3 interface.
Command system-view interface interface-type interface-number ospfv3 network-type
{ broadcast | nbma | p2mp
[ unicast ] | p2p } [ instance instance-id ]
Remarks
N/A
N/A
By default, the network type of an interface depends on the media type of the interface.
Configuring an NBMA or P2MP neighbor
For NBMA and P2MP interfaces (only when in unicast mode), you must specify the link-local IP addresses of their neighbors because these interfaces cannot find neighbors through broadcasting hello packets. For NBMA interfaces, you can also specify DR priorities for neighbors.
To configure an NBMA or P2MP (unicast) neighbor and its DR priority:
Step
1. Enter system view.
Remarks
N/A
2. Enter interface view.
3. Specify an NBMA or P2MP
(unicast) neighbor and its DR priority.
Command system-view interface interface-type interface-number ospfv3 peer ipv6-address [ cost value | dr-priority dr-priority ]
[ instance instance-id ]
N/A
By default, no link-local address is specified for the neighbor interface.
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Configuring OSPFv3 route control
Configuration prerequisites
Before you configure OSPFv3 route control, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
•
Enable OSPFv3.
Configuring OSPFv3 route summarization
Route summarization enables an ABR or ASBR to summarize contiguous networks into a single network and advertise it to other areas.
Configuring route summarization on an ABR
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.
To configure route summarization:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
N/A
3. Enter OSPFv3 area view.
area area-id N/A
4. Configure route summarization. abr-summary ipv6-address prefix-length [ not-advertise ] [ cost value ]
By default, route summarization is not configured on an ABR.
Configuring route summarization on an ASBR
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 by the ASBR (also an ABR) from Type-7 LSAs in an NSSA area.
If the ASBR (ABR) is not a translator, it cannot summarize routes in Type-5 LSAs translated from Type-7 LSAs.
To configure route summarization on an ASBR:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
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Step
3. Configure route summarization on an
ASBR.
Command asbr-summary ipv6-address prefix-length [ cost cost | not-advertise | nssa-only | tag tag ] *
Remarks
By default, route summarization is not configured on an ASBR.
Configuring OSPFv3 received route filtering
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure OSPFv3 to filter routes calculated using received LSAs. filter-policy { acl6-number [ gateway prefix-list-name ] | prefix-list prefix-list-name [ gateway prefix-list-name ] | gateway prefix-list-name | route-policy route-policy-name } import
Configuring Inter-Area-Prefix LSA filtering
Remarks
N/A
N/A
By default, OSPFv3 accepts all routes calculated 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.
Step
1. Enter system view.
Command 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 { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } { export | import }
Remarks
N/A
N/A
N/A
By default, OSPFv3 accepts all
Inter-Area-Prefix LSAs.
This command takes effect only on ABRs.
Configuring an OSPFv3 cost for an interface
You can configure an OSPFv3 cost for an interface with one of the following methods:
•
Configure the cost value in interface view.
•
Configure 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)
ï‚¡
If the calculated cost is greater than 65535, the value of 65535 is used.
ï‚¡
If the calculated cost is smaller than 1, the value of 1 is used.
•
If no cost is configured for an interface, OSPFv3 automatically computes the cost for the interface.
To configure an OSPFv3 cost for an interface:
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Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Configure an OSPFv3 cost for the interface.
ospfv3 cost value
[ instance instance-id ]
To configure a bandwidth reference value:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Configure a bandwidth reference value.
bandwidth-reference value
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.
Remarks
N/A
N/A
The default setting is 100 Mbps.
Configuring the maximum number of OSPFv3 ECMP routes
Perform this task to implement load sharing over ECMP routes.
To configure the maximum number of ECMP routes:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Specify the maximum number of ECMP routes. maximum load-balancing maximum
By default, the maximum number of OSPFv3 ECMP routes equals the maximum number of ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of ECMP routes supported by the system.
For more information about the max-ecmp-num command, see
Layer 3—IP Routing Command
Reference.
Configuring a preference for OSPFv3
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.
To configure a preference for OSPFv3:
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Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] * preference [ ase ]
[ route-policy route-policy-name ] preference
Remarks
N/A
N/A
By default, the preference of OSPFv3 internal routes is 10, and the priority of
OSPFv3 external routes is 150.
3. Configure a preference for OSPFv3.
Configuring OSPFv3 route redistribution
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.
Redistributing routes from another routing protocol
IMPORTANT:
The import-route bgp4+ command redistributes only EBGP routes. Because the import-route bgp4+ allow-ibgp command redistributes both EBGP and IBGP routes, and might cause routing loops, use it with caution.
To configure OSPFv3 route redistribution:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter OSPFv3 view.
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
N/A
3. Configure OSPFv3 to redistribute routes from other routing protocols. import-route protocol [ process-id |
all-processes | allow-ibgp ] [ cost cost | nssa-only | route-policy route-policy-name | tag tag | type type ]
*
By default, route redistribution is disabled.
4. (Optional.) Configure
OSPFv3 to filter redistributed routes. filter-policy { acl6-number | prefix-list prefix-list-name } export [ protocol
[ process-id ] ]
By default, OSPFv3 accepts all redistributed routes.
This command filters only routes redistributed with the import-route command. If the import-route command is not configured, executing this command does not take effect.
Redistributing a default route
The import-route command cannot redistribute a default external route. Perform this task to redistribute a default route.
To redistribute a default route:
Step
1. Enter system view.
Command system-view
Remarks
N/A
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Step
2. Enter OSPFv3 view.
Command ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
3. Redistribute a default route. default-route-advertise [ [ always | permit-calculate-other ] | cost cost | route-policy route-policy-name | tag tag
| type type ] *
Configuring tags for redistributed routes
By default, no default route is redistributed.
Perform this task to configure tags for redistributed routes to identify information about protocols. For example, when redistributing IPv6 BGP routes, OSPFv3 uses tags to identify AS IDs.
To configure a tag for redistributed routes:
Step
1. Enter system view.
2. Enter OSPFv3 view.
3. Configure a tag for redistributed routes.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
default tag tag
Remarks
N/A
N/A
By default, the tag of redistributed routes is 1.
Tuning and optimizing OSPFv3 networks
This section describes configurations of OSPFv3 timers, interface DR priority, and the logging of neighbor state changes.
Configuration prerequisites
Before you tune and optimize OSPFv3 networks, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
•
Enable OSPFv3.
Configuring OSPFv3 timers
Step
1. Enter system view.
2. Enter interface view.
3. Set the hello interval.
4. Set the dead interval.
Command system-view
interface interface-type interface-number ospfv3 timer hello seconds
[ instance instance-id ]
Remarks
N/A
N/A ospfv3 timer dead seconds
[ instance instance-id ]
By default, the hello interval on P2P and broadcast interfaces is 10 seconds.
By default, the dead interval on P2P and broadcast interfaces is 40 seconds.
The dead interval set on neighboring interfaces cannot be too short.
Otherwise, a neighbor is easily considered down.
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Step
5. Set the poll interval.
Command ospfv3 timer poll seconds
[ instance instance-id ]
6. Set the LSA retransmission interval. ospfv3 timer retransmit interval [ instance instance-id ]
Remarks
By default, the poll interval is 120 seconds.
The default setting is 5 seconds.
The LSA retransmission interval cannot be too short. Otherwise, unnecessary retransmissions will occur.
Specifying LSA transmission delay
Each LSA in the LSDB has an age that is incremented 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.
To specify the LSA transmission delay on an interface:
Remarks
N/A
Step
1. Enter system view.
Command system-view
2. Enter interface view.
interface interface-type interface-number
3. Specify the LSA transmission delay.
ospfv3 trans-delay seconds
[ instance instance-id ]
N/A
By default, the LSA transmission delay is 1 second.
Specifying SPF calculation interval
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 is incremented 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.
To configure SPF calculation interval:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Specify 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.
•
The incremental interval is
200 milliseconds.
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Specifying the LSA generation interval
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 is incremented 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.
To configure the LSA generation interval:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Configure 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.
Configuring a DR priority for an interface
The router priority is used for DR election. Interfaces having the priority 0 cannot become a DR or
BDR.
To configure a DR priority for an interface:
Step
1. Enter system view.
2. Enter interface view.
3. Configure a router priority.
Command system-view
Remarks
N/A
interface interface-type interface-number N/A ospfv3 dr-priority priority [ instance instance-id ]
The default router priority is 1.
Ignoring MTU check for DD packets
When LSAs are few in DD packets, it is unnecessary to check the MTU in DD packets to improve efficiency.
To ignore MTU check for DD packets:
Step
1. Enter system view.
2. Enter interface view.
Command system-view
interface interface-type interface-number
Remarks
N/A
N/A
3. Ignore MTU check for DD packets.
ospfv3 mtu-ignore [ instance instance-id ]
By default, OSPFv3 does not ignore MTU check for DD packets.
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Disabling interfaces from receiving and sending OSPFv3 packets
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.
To disable interfaces from receiving and sending OSPFv3 packets:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Disable interfaces from receiving and sending
OSPFv3 packets. silent-interface { interface-type interface-number | all }
By default, the interfaces are able to receive and send OSPFv3 packets.
This command disables only the interfaces associated with the current process. However, multiple OSPFv3 processes can disable the same interface from receiving and sending OSPFv3 packets.
Enabling the logging of neighbor state changes
With this feature enabled, the router delivers logs about neighbor state changes to its information center, which processes logs according to user-defined output rules (whether to output logs and where to output). For more information about the information center, see Network Management and
Monitoring Configuration Guide .
To enable the logging of neighbor state changes:
Step
1. Enter system view.
2. Enter OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
3. Enable the logging of neighbor state changes. log-peer-change By default, this feature is enabled.
Configuring OSPFv3 network management
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.
•
Configure the SNMP notification output interval and the maximum number of SNMP notifications that can be output at each interval.
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SNMP notifications are sent to the SNMP module, which outputs SNMP notifications according to the configured output rules. For more information about SNMP notifications, see Network Management and Monitoring Configuration Guide .
The standard OSPFv3 MIB provides only single-instance MIB objects. For SNMP to correctly identify
OSPFv3 management information in the standard OSPFv3 MIB, you must configure a unique context name for OSPFv3. If multiple OSPFv3 processes exist, you must assign a unique context to each 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.
To configure OSPFv3 network management:
Step
1. Enter system view.
Command system-view
2. Bind OSPFv3 MIB to an
OSPFv3 process.
ospfv3 mib-binding process-id
Remarks
N/A
By default, OSPFv3 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 | virtneighbor-state-change ]*
By default, SNMP notifications for OSPFv3 are enabled.
4. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
N/A
5. (Optional.) Configure an
SNMP context for
OSPFv3.
6. (Optional.) Configure the SNMP notification output interval and the maximum number of
SNMP notifications that can be output at each interval. snmp context-name context-name
By default, no SNMP context is configured for OSPFv3.
snmp trap rate-limit interval trap-interval
count trap-number
By default, OSPFv3 outputs a maximum of seven SNMP notifications within 10 seconds.
Configuring the LSU transmit rate
Sending large numbers of LSU packets affects router performance and consumes too much network bandwidth. You can configure the router to send LSU packets at a proper interval and limit the maximum number of LSU packets sent out of an OSPFv3 interface each time.
To configure the LSU transmit rate:
Step Command
1. Enter system view. system-view
2. Enter OSPFv3 view.
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
Remarks
N/A
N/A
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Step
3. Configure the LSU transmit rate.
Command transmit-pacing interval interval count count
Remarks
By default, an OSPFv3 interface sends a maximum of three LSU packets every 20 milliseconds.
Configuring stub routers
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.
To configure a router as a stub router:
Step
1. Enter system view.
2. Enter OSPFv3 view.
3. Configure the router as a stub router.
Command system-view
Remarks
N/A ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
•
Method 1: stub-router r-bit [ include-stub | on-startup { seconds | wait-for-bgp [ seconds ] } ] *
•
Method 2: stub-router max-metric
[ external-lsa [ max-metric-value ]
| summary-lsa
[ max-metric-value ] | include-stub | on-startup
{ seconds | wait-for-bgp
[ seconds ] } ] *
N/A
By default, the router is not configured as a stub router.
A stub router is not related to a stub area.
Configuring prefix suppression
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 function 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.
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IMPORTANT:
If you want to use prefix suppression, as a best practice, configure prefix suppression on all OSPFv3 routers.
Configuring prefix suppression for an OSPFv3 process
Enabling prefix suppression for an OSPFv3 process does not suppress the prefixes of loopback interfaces and passive interfaces.
To configure prefix suppression for an OSPFv3 process:
Remarks
N/A
Step Command
1. Enter system view. system-view
2. Enter OSPFv3 view.
ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
3. Enable prefix suppression for the
OSPFv3 process. prefix-suppression
Configuring prefix suppression for an interface
N/A
By default, prefix suppression is disabled for an OSPFv3 process.
Step Command
1. Enter system view. system-view
2. Enter interface view.
3. Enable prefix suppression for the interface. interface interface-type interface-number ospfv3 prefix-suppression [ disable ]
[ instance instance-id ]
Remarks
N/A
N/A
By default, prefix suppression is disabled on an interface.
Configuring 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 complete 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.
Configuring GR restarter
You can configure the GR restarter capability on a GR restarter.
363
IMPORTANT:
You cannot enable OSPFv3 NSR on a device that acts as GR restarter.
To configure GR restarter:
Step
1. Enter system view.
2. Enter OSPFv3 view.
3. Enable the GR capability.
4. (Optional.) Configure the GR interval.
Command system-view
Remarks
N/A ospfv3 [ process-id | vpn-instance vpn-instance-name ] *
N/A graceful-restart enable [ global | planned-only ] *
By default, OSPFv3 GR restarter capability is disabled. graceful-restart interval interval-value
By default, the GR interval is 120 seconds.
Configuring GR helper
You can configure the GR helper capability on a GR helper.
To configure GR helper:
Step
1. Enter system view.
2. Enter OSPFv3 view.
3. Enable the GR helper capability.
4. Enable strict LSA checking.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] * graceful-restart helper enable
[ planned-only ] graceful-restart helper strict-lsa-checking
Remarks
N/A
N/A
By default, the GR helper capability is enabled.
By default, strict LSA checking is disabled.
Triggering OSPFv3 GR
OSPFv3 GR is triggered by an active/standby switchover or when the following command is executed.
To trigger OSPFv3 GR, perform the following command in user view:
Task
Trigger OSPFv3 GR.
Command reset ospfv3 [ process id ] process graceful-restart
Configuring OSPFv3 NSR
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 is used more often than GR.
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To enable OSPFv3 NSR:
Step Command
1. Enter system view. system-view
2. Enter OSPFv3 view.
3. Enable OSPFv3
NSR. ospfv3 [ process-id | vpn-instance vpn-instance-name ] * non-stop-routing
Remarks
N/A
N/A
By default, OSPFv3 NSR is disabled.
Configuring BFD for OSPFv3
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.
To configure BFD for OSPFv3, you need to configure OSPFv3 first.
To configure BFD for OSPFv3:
Remarks
N/A
Step
1. Enter system view.
2. Enter OSPFv3 view.
3. Specify a router ID.
4. Quit the OSPFv3 view.
Command system-view ospfv3 [ process-id | vpn-instance vpn-instance-name ] * router-id router-id quit
5.
6.
Enter interface view.
Enable an OSPFv3 process on the interface. interface interface-type interface-number
ospfv3 process-id area area-id
[ instance instance-id ]
7. Enable BFD on the interface. ospfv3 bfd enable [ instance instance-id ]
N/A
N/A
N/A
N/A
N/A
By default, BFD on the interface is disabled.
Applying an IPsec profile
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 uses the SPI carried in a received packet to match against 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.
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.
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•
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 information about sham link, 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 each have an IPsec profile configured, the sham link uses its own
IPsec profile.
To apply an IPsec profile to an area:
Remarks
N/A
Step
1. Enter system view.
Command system-view
2. Enter OSPFv3 view.
3. Enter OSPFv3 area view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] * area area-id
4. Apply an IPsec profile to the area. enable ipsec-profile profile-name
To apply an IPsec profile to an interface:
N/A
N/A
By default, no IPsec profile is applied.
Step
1. Enter system view.
Command system-view
2. Enter interface view. interface interface-type interface-number
3. Apply an IPsec profile to the interface. ospfv3 ipsec-profile profile-name
To apply an IPsec profile to a virtual link:
Remarks
N/A
N/A
By default, no IPsec profile is applied.
Step
1. Enter system view.
Command 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.
vlink-peer router-id [ dead seconds |
hello seconds | instance instance-id |
retransmit seconds | trans-delay seconds | ipsec-profile profile-name ] *
To apply an IPsec profile to a sham link:
Step
1. Enter system view.
Command system-view
Remarks
N/A
N/A
N/A
By default, no IPsec profile is applied.
Remarks
N/A
366
Step Command
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.
Remarks
N/A
N/A
sham-link source-ipv6-address destination-ipv6-address [ cost cost |
dead dead-interval | hello hello-interval |
instance instance-id | ipsec-profile profile-name | retransmit retrans-interval
| trans-delay delay ] *
By default, no IPsec profile is applied.
Displaying and maintaining OSPFv3
Execute display commands in any view and reset commands in user view.
Purpose
Display information about the routes to OSPFv3 ABR and ASBR.
Command display ospfv3 [ process-id ] abr-asbr
Display summary route information on the OSPFv3 ABR. display ospfv3 [ process-id ] [ area area-id ] abr-summary
[ ipv6-address prefix-length ] [ verbose ]
Display summary route information on the OSPFv3 ASBR. display ospfv3 [ process-id ] asbr-summary [ ipv6-address prefix-length ] [ verbose ]
Display OSPFv3 process information. display ospfv3 [ process-id ] [ verbose ]
Display OSPFv3 GR information. display ospfv3 [ process-id ] graceful-restart [ verbose ]
Display OSPFv3 interface information.
Display OSPFv3 LSDB information. display ospfv3 [ interface-number process-id
| verbose
]
] interface [ interface-type 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 [ interface-number process-id
] [
] [ verbose ] | area area-id ] peer
peer-router-id |
[ [ interface-type statistics ]
Display OSPFv3 request list information. display ospfv3 [ process-id ] [ area area-id ] request-queue
[ interface-type interface-number ] [ neighbor-id ]
Display OSPFv3 retransmission list information. display ospfv3
[
[ process-id ] [ area interface-type interface-number ] [ area-id ] retrans-queue neighbor-id ]
Display OSPFv3 routing information. display ospfv3 [ process-id ] routing [ ipv6-address prefix-length ]
Display OSPFv3 topology information. display ospfv3 [ process-id ] [ area area-id ] spf-tree [ verbose ]
Display OSPFv3 statistics. display ospfv3 [ process-id ] statistics [ error ]
Display OSPFv3 virtual link information. display ospfv3 [ process-id ] vlink
Restart an OSPFv3 process. reset ospfv3 [ process-id ] process [ graceful-restart ]
Restart OSPFv3 route redistribution. reset ospfv3 [ process-id ] redistribution
Clear OSPFv3 statistics. reset ospfv3 [ process-id ] statistics
367
OSPFv3 configuration examples
OSPFv3 stub area configuration example
Network requirements
•
Enable OSPFv3 on all switches.
•
Split the AS into three areas.
•
Configure Switch B and Switch 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 88 Network diagram
OSPFv3
Switch B
Vlan-int100
Area 0
2001::1/64
Vlan-int100
2001::2/64
Vlan-int200
2001:1::1/64
Switch C
Vlan-int400
2001:2::1/64
OSPFv3
Area 1
Vlan-int200
2001:1::2/64
OSPFv3
Area 2
Vlan-int400
2001:2::2/64
Switch A
Vlan-int300
2001:3::1/64
Switch D
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Switch A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 300
[SwitchA-Vlan-interface300] ospfv3 1 area 1
[SwitchA-Vlan-interface300] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ospfv3 1 area 1
[SwitchA-Vlan-interface200] quit
# On Switch B, enable OSPFv3 and specify the router ID as 2.2.2.2.
<SwitchB> system-view
[SwitchB] ospfv3
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ospfv3 1 area 0
[SwitchB-Vlan-interface100] quit
368
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ospfv3 1 area 1
[SwitchB-Vlan-interface200] quit
# On Switch C, enable OSPFv3 and specify the router ID as 3.3.3.3.
<SwitchC> system-view
[SwitchC] ospfv3
[SwitchC-ospfv3-1] router-id 3.3.3.3
[SwitchC-ospfv3-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] ospfv3 1 area 0
[SwitchC-Vlan-interface100] quit
[SwitchC] interface vlan-interface 400
[SwitchC-Vlan-interface400] ospfv3 1 area 2
[SwitchC-Vlan-interface400] quit
# On Switch D, enable OSPFv3 and specify the router ID as 4.4.4.4.
<SwitchD> system-view
[SwitchD] ospfv3
[SwitchD-ospfv3-1] router-id 4.4.4.4
[SwitchD-ospfv3-1] quit
[SwitchD] interface vlan-interface 400
[SwitchD-Vlan-interface400] ospfv3 1 area 2
[SwitchD-Vlan-interface400] quit
# Display OSPFv3 neighbors on Switch B.
[SwitchB] 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 Vlan100
Area: 0.0.0.1
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
1.1.1.1 1 Full/DR 00:00:40 0 Vlan200
# Display OSPFv3 neighbors on Switch C.
[SwitchC] display ospfv3 peer
OSPFv3 Process 1 with Router ID 3.3.3.3
Area: 0.0.0.0
-------------------------------------------------------------------------
Router ID Pri State Dead-Time InstID Interface
2.2.2.2 1 Full/DR 00:00:40 0 Vlan100
Area: 0.0.0.2
-------------------------------------------------------------------------
369
Router ID Pri State Dead-Time InstID Interface
4.4.4.4 1 Full/BDR 00:00:40 0 Vlan400
# Display OSPFv3 routing table information on Switch D.
[SwitchD] 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 Cost : 2
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:1::/64
Type : IA Cost : 3
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:2::/64
Type : I Cost : 1
Nexthop : :: Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
*Destination: 2001:3::/64
Type : IA Cost : 4
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
Total: 4
Intra area: 1 Inter area: 3 ASE: 0 NSSA: 0
3. Configure Area 2 as a stub area:
# Configure Switch D.
[SwitchD] ospfv3
[SwitchD-ospfv3-1] area 2
[SwitchD-ospfv3-1-area-0.0.0.2] stub
# Configure Switch C, and specify the cost of the default route sent to the stub area as 10.
[SwitchC] ospfv3
[SwitchC-ospfv3-1] area 2
[SwitchC-ospfv3-1-area-0.0.0.2] stub
[SwitchC-ospfv3-1-area-0.0.0.2] default-cost 10
# Display OSPFv3 routing table information on Switch D.
370
[SwitchD] 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 Cost : 11
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
*Destination: 2001::/64
Type : IA Cost : 2
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:1::/64
Type : IA Cost : 3
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:2::/64
Type : I Cost : 1
Nexthop : :: Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
*Destination: 2001:3::/64
Type : IA Cost : 4
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
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:
# Configure Area 2 as a totally stub area on Switch C.
[SwitchC-ospfv3-1-area-0.0.0.2] stub no-summary
# Display OSPFv3 routing table information on Switch D.
[SwitchD] display ospfv3 routing
371
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 Cost : 11
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
*Destination: 2001:2::/64
Type : I Cost : 1
Nexthop : :: Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
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.
OSPFv3 NSSA area configuration example
Network requirements
•
Configure OSPFv3 on all switches and split the AS into three areas.
•
Configure Switch B and Switch C as ABRs to forward routing information between areas.
•
Configure Area 1 as an NSSA area and configure Switch A as an ASBR to redistribute static routes into the AS.
Figure 89 Network diagram
OSPFv3
Switch B
Vlan-int100
Area 0
2001::1/64
Vlan-int200
2001:1::1/64
Vlan-int100
2001::2/64
Switch C
Vlan-int400
2001:2::1/64
OSPFv3
Area 1
Vlan-int200
2001:1::2/64
OSPFv3
Area 2
Vlan-int400
2001:2::2/64
Switch A
Vlan-int300
2001:3::1/64
Switch D
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2.
Configure basic OSPFv3 (see " OSPFv3 stub area configuration example ").
372
3. Configure Area 1 as an NSSA area:
# Configure Switch A.
[SwitchA] ospfv3
[SwitchA-ospfv3-1] area 1
[SwitchA-ospfv3-1-area-0.0.0.1] nssa
[SwitchA-ospfv3-1-area-0.0.0.1] quit
[SwitchA-ospfv3-1] quit
# Configure Switch B.
[SwitchB] ospfv3
[SwitchB-ospfv3-1] area 1
[SwitchB-ospfv3-1-area-0.0.0.1] nssa
[SwitchB-ospfv3-1-area-0.0.0.1] quit
[SwitchB-ospfv3-1] quit
# Display OSPFv3 routing information on Switch A.
[SwitchA] display ospfv3 1 routing
OSPFv3 Process 1 with Router ID 1.1.1.1
-------------------------------------------------------------------------
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 Cost : 2
NextHop : FE80::20C:29FF:FE74:59C6 Interface: Vlan200
AdvRouter : 2.2.2.2 Area : 0.0.0.1
Preference : 10
*Destination: 2001:1::/64
Type : I Cost : 1
Nexthop : :: Interface: Vlan200
AdvRouter : 1.1.1.1 Area : 0.0.0.1
Preference : 10
*Destination: 2001:2::/64
Type : IA Cost : 3
NextHop : FE80::20C:29FF:FE74:59C6 Interface: Vlan200
AdvRouter : 2.2.2.2 Area : 0.0.0.1
Preference : 10
Total: 3
Intra area: 1 Inter area: 2 ASE: 0 NSSA: 0
4. Configure route redistribution:
# Configure an IPv6 static route, and configure OSPFv3 to redistribute the static route on
Switch A.
[SwitchA] ipv6 route-static 1234:: 64 null 0
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] import-route static
373
[SwitchA-ospfv3-1] quit
# Display OSPFv3 routing information on Switch D.
[SwitchD] 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 Cost : 2
NextHop : FE80::20C:29FF:FEB9:F2EF Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:1::/64
Type : IA Cost : 3
NextHop : FE80::20C:29FF:FEB9:F2EF Interface: Vlan400
AdvRouter : 3.3.3.3 Area : 0.0.0.2
Preference : 10
*Destination: 2001:2::/64
Type : I Cost : 1
NextHop : :: Interface: Vlan400
AdvRouter : 4.4.4.4 Area : 0.0.0.2
Preference : 10
*Destination: 1234::/64
Type : E2 Cost : 1
NextHop : FE80::20C:29FF:FEB9:F2EF Interface: Vlan400
AdvRouter : 2.2.2.2 Area : 0.0.0.2
Preference : 10
Total: 4
Intra area: 1 Inter area: 2 ASE: 1 NSSA: 0
The output shows an AS external route imported from the NSSA area exists on Switch D.
OSPFv3 DR election configuration example
Network requirements
•
Configure router priority 100 for Switch A, the highest priority on the network, so it will become the DR.
•
Configure router priority 2 for Switch C, the second highest priority on the network, so it will become the BDR.
•
Configure router priority 0 for Switch B, so it cannot become a DR or BDR.
•
Switch D uses the default router priority 1.
374
Figure 90 Network diagram
Switch A
Vlan-int100
2001::1/64
Switch B
Vlan-int200
2001::2/64
Vlan-int100
2001::3/64
Vlan-int200
2001::4/64
Switch C Switch D
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Switch A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 1 area 0
[SwitchA-Vlan-interface100] quit
# On Switch B, enable OSPFv3 and specify the router ID as 2.2.2.2.
<SwitchB> system-view
[SwitchB] ospfv3
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ospfv3 1 area 0
[SwitchB-Vlan-interface200] quit
# On Switch C, enable OSPFv3 and specify the router ID as 3.3.3.3.
<SwitchC> system-view
[SwitchC] ospfv3
[SwitchC-ospfv3-1] router-id 3.3.3.3
[SwitchC-ospfv3-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] ospfv3 1 area 0
[SwitchC-Vlan-interface100] quit
# On Switch D, enable OSPFv3 and specify the router ID as 4.4.4.4.
<SwitchD> system-view
[SwitchD] ospfv3
[SwitchD-ospfv3-1] router-id 4.4.4.4
[SwitchD-ospfv3-1] quit
[SwitchD] interface vlan-interface 200
[SwitchD-Vlan-interface200] ospfv3 1 area 0
375
[SwitchD-Vlan-interface200] quit
# Display neighbor information on Switch A. The switches have the same default DR priority 1, so Switch D (the switch with the highest router ID) is elected as the DR, and Switch C is the
BDR.
[SwitchA] 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 Vlan200
3.3.3.3 1 Full/BDR 00:00:35 0 Vlan100
4.4.4.4 1 Full/DR 00:00:33 0 Vlan200
# Display neighbor information on Switch D. The neighbor states are all full.
[SwitchD] 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 Vlan100
2.2.2.2 1 Full/DROther 00:00:37 0 Vlan200
3.3.3.3 1 Full/BDR 00:00:31 0 Vlan100
3. Configure router priorities for interfaces:
# Set the router priority of VLAN-interface 100 to 100 on Switch A.
[SwitchA] interface Vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 dr-priority 100
[SwitchA-Vlan-interface100] quit
# Set the router priority of VLAN-interface 200 to 0 on Switch B.
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ospfv3 dr-priority 0
[SwitchB-Vlan-interface200] quit
# Set the router priority of VLAN-interface 100 to 2 on Switch C.
[SwitchC] interface Vlan-interface 100
[SwitchC-Vlan-interface100] ospfv3 dr-priority 2
[SwitchC-Vlan-interface100] quit
# Display neighbor information on Switch A. Router priorities have been updated, but the DR and BDR are not changed.
[SwitchA] 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 Vlan200
376
3.3.3.3 2 Full/BDR 00:00:35 0 Vlan200
4.4.4.4 1 Full/DR 00:00:33 0 Vlan200
# Display neighbor information on Switch D. Switch D is still the DR.
[SwitchD] 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 Vlan100
2.2.2.2 0 Full/DROther 00:00:37 0 Vlan200
3.3.3.3 2 Full/BDR 00:00:31 0 Vlan100
4. Restart DR and BDR election:
# Use the shutdown and undo shutdown commands on interfaces to restart DR and BDR election. (Details not shown.)
# Display neighbor information on Switch A. The output shows that Switch C becomes the BDR.
[SwitchA] 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 Vlan200
3.3.3.3 2 Full/BDR 00:00:35 0 Vlan100
4.4.4.4 1 Full/DROther 00:00:33 0 Vlan200
# Display neighbor information on Switch D.
[SwitchD] 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 Vlan100
2.2.2.2 0 2-Way/DROther 00:00:37 0 Vlan200
3.3.3.3 2 Full/BDR 00:00:31 0 Vlan100
The output shows that Switch A becomes the DR.
OSPFv3 route redistribution configuration example
Network requirements
•
Switch A, Switch B, and Switch C are in Area 2.
•
OSPFv3 process 1 and OSPFv3 process 2 run on Switch B. Switch B communicates with
Switch A and Switch C through OSPFv3 process 1 and OSPFv3 process 2.
377
•
Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process
1 on Switch B, and set the default metric for redistributed routes to 3. Switch C can then learn the routes destined for 1::0/64 and 2::0/64, and Switch A cannot learn the routes destined for
3::0/64 or 4::0/64.
Figure 91 Network diagram
Vlan-int200
2::1/64 Vlan-int100
1::1/64
Vlan-int300
3::2/64
Vlan-int400
4::1/64
Switch A Switch C
Process 1
Area 2
Process 2
Area 2
Vlan-int100
1::2/64
Vlan-int300
3::1/64
Switch B
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# Enable OSPFv3 process 1 on Switch A.
<SwitchA> system-view
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 1 area 2
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ospfv3 1 area 2
[SwitchA-Vlan-interface200] quit
# Enable OSPFv3 process 1 and OSPFv3 process 2 on Switch B.
<SwitchB> system-view
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ospfv3 1 area 2
[SwitchB-Vlan-interface100] quit
[SwitchB] ospfv3 2
[SwitchB-ospfv3-2] router-id 3.3.3.3
[SwitchB-ospfv3-2] quit
[SwitchB] interface vlan-interface 300
[SwitchB-Vlan-interface300] ospfv3 2 area 2
[SwitchB-Vlan-interface300] quit
# Enable OSPFv3 process 2 on Switch C.
<SwitchC> system-view
[SwitchC] ospfv3 2
[SwitchC-ospfv3-2] router-id 4.4.4.4
[SwitchC-ospfv3-2] quit
378
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] ospfv3 2 area 2
[SwitchC-Vlan-interface300] quit
[SwitchC] interface vlan-interface 400
[SwitchC-Vlan-interface400] ospfv3 2 area 2
[SwitchC-Vlan-interface400] quit
# Display the routing table on Switch C.
[SwitchC] display ipv6 routing-table
Destinations : 7 Routes : 7
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
Interface : Vlan300 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 : Vlan400 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
3. Configure OSPFv3 route redistribution:
# Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process 1 on Switch B.
[SwitchB] ospfv3 2
[SwitchB-ospfv3-2] default cost 3
[SwitchB-ospfv3-2] import-route ospfv3 1
[SwitchB-ospfv3-2] import-route direct
[SwitchB-ospfv3-2] quit
# Display the routing table on Switch C.
[SwitchC] display ipv6 routing-table
379
Destinations : 9 Routes : 9
Destination: ::1/128 Protocol : Direct
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 1::/64 Protocol : OSPFv3
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 3
Destination: 2::/64 Protocol : OSPFv3
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 3
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
Interface : Vlan300 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 : Vlan400 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
OSPFv3 route summarization configuration example
Network requirements
•
Switch A, Switch B, and Switch C are in Area 2.
•
OSPFv3 process 1 and OSPFv3 process 2 run on Switch B. Switch B communicates with
Switch A and Switch C through OSPFv3 process 1 and OSPFv3 process 2, respectively.
•
On Switch A, configure IPv6 addresses 2:1:1::1/64, 2:1:2::1/64, and 2:1:3::1/64 for
VLAN-interface 200.
380
•
On Switch B, configure OSPFv3 process 2 to redistribute direct routes and the routes from
OSPFv3 process 1. Switch C can then learn the routes destined for 2::/64, 2:1:1::/64, 2:1:2::/64, and 2:1:3::/64.
•
On Switch B, configure route summarization to advertise only summary route 2::/16 to Switch
C.
Figure 92 Network diagram
Vlan-int200
2::1/64 Vlan-int100
1::1/64
Vlan-int300
3::2/64
Vlan-int400
4::1/64
Switch A Switch C
Process 1
Area 2
Process 2
Area 2
Vlan-int100
1::2/64
Vlan-int300
3::1/64
Switch B
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3:
# Enable OSPFv3 process 1 on Switch A.
<SwitchA> system-view
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 1 area 2
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ipv6 address 2:1:1::1 64
[SwitchA-Vlan-interface200] ipv6 address 2:1:2::1 64
[SwitchA-Vlan-interface200] ipv6 address 2:1:3::1 64
[SwitchA-Vlan-interface200] ospfv3 1 area 2
[SwitchA-Vlan-interface200] quit
# Enable OSPFv3 process 1 and OSPFv3 process 2 on Switch B.
<SwitchB> system-view
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ospfv3 1 area 2
[SwitchB-Vlan-interface100] quit
[SwitchB] ospfv3 2
[SwitchB-ospfv3-2] router-id 3.3.3.3
[SwitchB-ospfv3-2] quit
[SwitchB] interface vlan-interface 300
[SwitchB-Vlan-interface300] ospfv3 2 area 2
[SwitchB-Vlan-interface300] quit
# Enable OSPFv3 process 2 on Switch C.
381
<SwitchC> system-view
[SwitchC] ospfv3 2
[SwitchC-ospfv3-2] router-id 4.4.4.4
[SwitchC-ospfv3-2] quit
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] ospfv3 2 area 2
[SwitchC-Vlan-interface300] quit
[SwitchC] interface vlan-interface 400
[SwitchC-Vlan-interface400] ospfv3 2 area 2
[SwitchC-Vlan-interface400] quit
3. Configure OSPFv3 route redistribution:
# Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process 1 on Switch B.
[SwitchB] ospfv3 2
[SwitchB-ospfv3-2] import-route ospfv3 1
[SwitchB-ospfv3-2] import-route direct
[SwitchB-ospfv3-2] quit
# Display the routing table on Switch C.
[SwitchC] 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 : Vlan300 Cost : 1
Destination: 2::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 1
Destination: 2:1:1::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 1
Destination: 2:1:2::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 1
Destination: 2:1:3::/64 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 1
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
382
Interface : Vlan300 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 : Vlan400 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
4. Configure ASBR route summarization:
# On Switch B, configure OSPFv3 process 2 to advertise a single route 2::/16.
[SwitchB] ospfv3 2
[SwitchB-ospfv3-2] asbr-summary 2:: 16
[SwitchB-ospfv3-2] quit
# Display the routing table on Switch C.
[SwitchC] 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 : Vlan300 Cost : 1
Destination: 2::/16 Protocol : O_ASE2
NextHop : FE80::200:CFF:FE01:1C03 Preference: 150
Interface : Vlan300 Cost : 1
Destination: 3::/64 Protocol : Direct
NextHop : 3::2 Preference: 0
Interface : Vlan300 Cost : 0
Destination: 3::2/128 Protocol : Direct
383
NextHop : ::1 Preference: 0
Interface : InLoop0 Cost : 0
Destination: 4::/64 Protocol : Direct
NextHop : 4::1 Preference: 0
Interface : Vlan400 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
OSPFv3 GR configuration example
Network requirements
•
Switch A, Switch B, and Switch C that reside in the same AS and the same OSPFv3 routing domain are GR capable.
•
Switch A acts as the GR restarter. Switch B and Switch C act as the GR helpers, and synchronize their LSDBs with Switch A through GR.
Figure 93 Network diagram
Router ID: 1.1.1.1
GR restarter
Switch A
Vlan-int100
2000::1/24
Vlan-int100
2000::2/24
Switch B
Vlan-int100
2000::3/24
Switch C
GR helper
Router ID: 2.2.2.2
GR helper
Router ID: 3.3.3.3
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Switch A, enable OSPFv3 process 1, enable GR, and set the router ID to 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] graceful-restart enable
384
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 1 area 1
[SwitchA-Vlan-interface100] quit
# On Switch B, enable OSPFv3 and set the router ID to 2.2.2.2. (By default, GR helper is enabled on Switch B.)
<SwitchB> system-view
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ospfv3 1 area 1
[SwitchB-Vlan-interface100] quit
# On Switch C, enable OSPFv3 and set the router ID to 3.3.3.3. (By default, GR helper is enabled on Switch C.)
<SwitchC> system-view
[SwitchC] ospfv3 1
[SwitchC-ospfv3-1] router-id 3.3.3.3
[SwitchC-ospfv3-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] ospfv3 1 area 1
[SwitchC-Vlan-interface100] quit
Verifying the configuration
# Perform a master/backup switchover on Switch A to trigger an OSPFv3 GR operation. (Details not shown.)
# Restart OSPFv3 on Switch A to trigger an OSPFv3 GR operation. (Details not shown.)
OSPFv3 NSR configuration example
Network requirements
As shown in Figure 94 , Switch S, Switch A, and Switch B belong to the same AS and OSPFv3
routing domain. Enable OSPFv3 NSR on Switch S to ensure correct routing when an active/standby switchover occurs on Switch S.
Figure 94 Network diagram
Loop 0
2002::2/128
Switch A
Vlan-int100
1200:1::1/64
Vlan-int100
1200:1::2/64
Switch S
Vlan-int200
1400:1::2/64
Vlan-int200
1400:1::1/64
Switch B
Loop 0
4004::4/128
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3:
# On Switch A, enable OSPFv3, and set the router ID to 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] router-id 1.1.1.1
385
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ospfv3 1 area 1
[SwitchA-Vlan-interface100] quit
# On Switch B, enable OSPFv3, and set the router ID to 2.2.2.2.
<SwitchB> system-view
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ospfv3 1 area 1
[SwitchB-Vlan-interface200] quit
# On Switch S, enable OSPFv3, set the router ID to 3.3.3.3, and enable NSR.
<SwitchS> system-view
[SwitchS] ospfv3 1
[SwitchS-ospfv3-1] router-id 3.3.3.3
[SwitchS-ospfv3-1] non-stop-routing
[SwitchS-ospfv3-1] quit
[SwitchS] interface vlan-interface 100
[SwitchS-Vlan-interface100] ospfv3 1 area 1
[SwitchS-Vlan-interface100] quit
[SwitchS] interface vlan-interface 200
[SwitchS-Vlan-interface200] ospfv3 1 area 1
[SwitchS-Vlan-interface200] quit
Verifying the configuration
# Perform an active/standby switchover on Switch S, and verify that NSR can ensure continuous traffic forwarding between Switch A and Switch B. (Details not shown.)
BFD for OSPFv3 configuration example
Network requirements
•
Configure OSPFv3 on Switch A, Switch B and Switch C and configure BFD over the link Switch
A<—>L2 Switch<—>Switch B.
•
After the link Switch A<—>L2 Switch<—>Switch B fails, BFD can quickly detect the failure and notify OSPFv3 of the failure. Then Switch A and Switch B communicate through Switch C.
386
Figure 95 Network diagram
2001:1::/64
Switch A
Vlan-int10
Vlan-int11
BFD
L2 Switch
Vlan-int10
Switch B
2001:4::/64
Vlan-int13
Area 0
Vlan-int11 Vlan-int13
Switch C
Table 21 Interface and IP address assignment
Device
Switch A
Switch A
Switch B
Switch B
Interface
Vlan-int10
Vlan-int11
Vlan-int10
Vlan-int13
IPv6 address
2001::1/64
2001:2::1/64
2001::2/64
2001:3::2/64
Switch C Vlan-int11 2001:2::2/64
Switch C Vlan-int13 2001:3::1/64
Configuration procedure
1. Configure IPv6 addresses for the interfaces. (Details not shown.)
2. Configure basic OSPFv3:
# On Switch A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ospfv3 1 area 0
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 11
[SwitchA-Vlan-interface11] ospfv3 1 area 0
[SwitchA-Vlan-interface11] quit
# On Switch B, enable OSPFv3 and specify the router ID as 2.2.2.2.
<SwitchB> system-view
[SwitchB] ospfv3
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ospfv3 1 area 0
[SwitchB-Vlan-interface10] quit
[SwitchB] interface vlan-interface 13
[SwitchB-Vlan-interface13] ospfv3 1 area 0
387
[SwitchB-Vlan-interface13] quit
# On Switch C, enable OSPFv3 and configure the router ID as 3.3.3.3.
<SwitchC> system-view
[SwitchC] ospfv3
[SwitchC-ospfv3-1] router-id 3.3.3.3
[SwitchC-ospfv3-1] quit
[SwitchC] interface vlan-interface 11
[SwitchC-Vlan-interface11] ospfv3 1 area 0
[SwitchC-Vlan-interface11] quit
[SwitchC] interface vlan-interface 13
[SwitchC-Vlan-interface13] ospfv3 1 area 0
[SwitchC-Vlan-interface13] quit
3. Configure BFD:
# Enable BFD and configure BFD parameters on Switch A.
[SwitchA] bfd session init-mode active
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ospfv3 bfd enable
[SwitchA-Vlan-interface10] bfd min-transmit-interval 500
[SwitchA-Vlan-interface10] bfd min-receive-interval 500
[SwitchA-Vlan-interface10] bfd detect-multiplier 7
[SwitchA-Vlan-interface10] return
# Enable BFD and configure BFD parameters on Switch B.
[SwitchB] bfd session init-mode active
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ospfv3 bfd enable
[SwitchB-Vlan-interface10] bfd min-transmit-interval 500
[SwitchB-Vlan-interface10] bfd min-receive-interval 500
[SwitchB-Vlan-interface10] bfd detect-multiplier 6
Verifying the configuration
# Display the BFD information on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Init Mode: Active
IPv6 Session Working Under Ctrl Mode:
Local Discr: 1441 Remote Discr: 1450
Source IP: FE80::20F:FF:FE00:1202 (link-local address of VLAN-interface 10 on
Switch A)
Destination IP: FE80::20F:FF:FE00:1200 (link-local address of VLAN-interface 10 on
Switch B)
Session State: Up Interface: Vlan10
Hold Time: 2319ms
# Display routes destined for 2001:4::0/64 on Switch A.
<SwitchA> display ipv6 routing-table 2001:4::0 64
Summary Count : 1
388
Destination: 2001:4::/64 Protocol : O_INTRA
NextHop : FE80::20F:FF:FE00:1200 Preference: 10
Interface : Vlan10 Cost : 1
The output information shows that Switch A communicates with Switch B through VLAN-interface 10.
The link over VLAN-interface 10 fails.
# Display routes to 2001:4::0/64 on Switch A.
<SwitchA> 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 : Vlan11 Cost : 2
The output shows that Switch A communicates with Switch B through VLAN-interface 11.
OSPFv3 IPsec profile configuration example
Network requirements
As shown in Figure 96 , all switches run OSPFv3, and the AS is divided into two areas.
Configure IPsec profiles on the switches to authenticate and encrypt protocol packets.
Figure 96 Network diagram
OSPFv3
Switch B
Vlan-int100
Area 0
2001::1/64
Vlan-int200
2001:1::1/64
Vlan-int100
2001::2/64
Switch C
OSPFv3
Area 1
Vlan-int200
2001:1::2/64
Switch A
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure OSPFv3 basic functions:
# On Switch A, enable OSPFv3 and specify the router ID as 1.1.1.1.
<SwitchA> system-view
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] router-id 1.1.1.1
[SwitchA-ospfv3-1] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ospfv3 1 area 1
[SwitchA-Vlan-interface200] quit
# On Switch B, enable OSPFv3 and specify the router ID as 2.2.2.2.
389
<SwitchB> system-view
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] router-id 2.2.2.2
[SwitchB-ospfv3-1] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ospfv3 1 area 0
[SwitchB-Vlan-interface100] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] ospfv3 1 area 1
[SwitchB-Vlan-interface200] quit
# On Switch C, enable OSPFv3 and specify the router ID as 3.3.3.3.
<SwitchC> system-view
[SwitchC] ospfv3 1
[SwitchC-ospfv3-1] router-id 3.3.3.3
[SwitchC-ospfv3-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] ospfv3 1 area 0
[SwitchC-Vlan-interface100] quit
3. Configure OSPFv3 IPsec profiles:
ï‚¡
On Switch A:
# Create an IPsec transform set named trans .
[SwitchA] ipsec transform-set trans
# Specify the encapsulation mode as transport .
[SwitchA-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[SwitchA-ipsec-transform-set-trans] esp encryption-algorithm 3des-cbc
[SwitchA-ipsec-transform-set-trans] esp authentication-algorithm md5
# Specify the AH authentication algorithm.
[SwitchA-ipsec-transform-set-trans] ah authentication-algorithm md5
[SwitchA-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile001 .
[SwitchA] ipsec profile profile001 manual
# Reference IPsec transform set trans .
[SwitchA-ipsec-profile-profile001-manual] transform-set trans
# Configure the inbound and outbound SPIs for AH.
[SwitchA-ipsec-profile-profile001-manual] sa spi inbound ah 111111111
[SwitchA-ipsec-profile-profile001-manual] sa spi outbound ah 111111111
# Configure the inbound and outbound SPIs for ESP.
[SwitchA-ipsec-profile-profile001-manual] sa spi inbound esp 200000
[SwitchA-ipsec-profile-profile001-manual] sa spi outbound esp 200000
# Configure the inbound and outbound SA keys for AH.
[SwitchA-ipsec-profile-profile001-manual] sa string-key inbound ah simple abc
[SwitchA-ipsec-profile-profile001-manual] sa string-key outbound ah simple abc
# Configure the inbound and outbound SA keys for ESP.
[SwitchA-ipsec-profile-profile001-manual] sa string-key inbound esp simple 123
[SwitchA-ipsec-profile-profile001-manual] sa string-key outbound esp simple 123
[SwitchA-ipsec-profile-profile001-manual] quit
390
ï‚¡
ï‚¡
On Switch B:
# Create an IPsec transform set named trans .
[SwitchB] ipsec transform-set trans
# Specify the encapsulation mode as transport .
[SwitchB-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[SwitchB-ipsec-transform-set-trans] esp encryption-algorithm 3des-cbc
[SwitchB-ipsec-transform-set-trans] esp authentication-algorithm md5
# Specify the AH authentication algorithm.
[SwitchB-ipsec-transform-set-trans] ah authentication-algorithm md5
[SwitchB-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile001 .
[SwitchB] ipsec profile profile001 manual
# Reference IPsec transform set trans .
[SwitchB-ipsec-profile-profile001-manual] transform-set trans
# Configure the inbound and outbound SPIs for AH.
[SwitchB-ipsec-profile-profile001-manual] sa spi inbound ah 111111111
[SwitchB-ipsec-profile-profile001-manual] sa spi outbound ah 111111111
# Configure the inbound and outbound SPIs for ESP.
[SwitchB-ipsec-profile-profile001-manual] sa spi inbound esp 200000
[SwitchB-ipsec-profile-profile001-manual] sa spi outbound esp 200000
# Configure the inbound and outbound SA keys for AH.
[SwitchB-ipsec-profile-profile001-manual] sa string-key inbound ah simple abc
[SwitchB-ipsec-profile-profile001-manual] sa string-key outbound ah simple abc
# Configure the inbound and outbound SA keys for ESP.
[SwitchB-ipsec-profile-profile001-manual] sa string-key inbound esp simple 123
[SwitchB-ipsec-profile-profile001-manual] sa string-key outbound esp simple 123
[SwitchB-ipsec-profile-profile001-manual] quit
# Create a manual IPsec profile named profile002 .
[SwitchB] ipsec profile profile002 manual
# Reference IPsec transform set trans .
[SwitchB-ipsec-profile-profile002-manual] transform-set trans
# Configure the inbound and outbound SPIs for AH.
[SwitchB-ipsec-profile-profile002-manual] sa spi inbound ah 4294967295
[SwitchB-ipsec-profile-profile002-manual] sa spi outbound ah 4294967295
# Configure the inbound and outbound SPIs for ESP.
[SwitchB-ipsec-profile-profile002-manual] sa spi inbound esp 256
[SwitchB-ipsec-profile-profile002-manual] sa spi outbound esp 256
# Configure the inbound and outbound SA keys for AH.
[SwitchB-ipsec-profile-profile002-manual] sa string-key inbound ah simple hello
[SwitchB-ipsec-profile-profile002-manual] sa string-key outbound ah simple hello
# Configure the inbound and outbound SA keys for ESP.
[SwitchB-ipsec-profile-profile002-manual] sa string-key inbound esp simple byebye
[SwitchB-ipsec-profile-profile002-manual] sa string-key outbound esp simple byebye
[SwitchB-ipsec-profile-profile002-manual] quit
On Switch C:
391
# Create an IPsec transform set named trans .
[SwitchC] ipsec transform-set trans
# Specify the encapsulation mode as transport .
[SwitchC-ipsec-transform-set-trans] encapsulation-mode transport
# Specify the ESP encryption and authentication algorithms.
[SwitchC-ipsec-transform-set-trans] esp encryption-algorithm 3des-cbc
# Specify the AH authentication algorithm.
[SwitchC-ipsec-transform-set-trans] esp authentication-algorithm md5
[SwitchC-ipsec-transform-set-trans] ah authentication-algorithm md5
[SwitchC-ipsec-transform-set-trans] quit
# Create a manual IPsec profile named profile002 .
[SwitchC] ipsec profile profile002 manual
# Reference IPsec transform set trans .
[SwitchC-ipsec-profile-profile002-manual] transform-set trans
# Configure the inbound and outbound SPIs for AH.
[SwitchC-ipsec-profile-profile002-manual] sa spi inbound ah 4294967295
[SwitchC-ipsec-profile-profile002-manual] sa spi outbound ah 4294967295
# Configure the inbound and outbound SPIs for ESP.
[SwitchC-ipsec-profile-profile002-manual] sa spi inbound esp 256
[SwitchC-ipsec-profile-profile002-manual] sa spi outbound esp 256
# Configure the inbound and outbound SA keys for AH.
[SwitchC-ipsec-profile-profile002-manual] sa string-key inbound ah simple hello
[SwitchC-ipsec-profile-profile002-manual] sa string-key outbound ah simple hello
# Configure the inbound and outbound SA keys for ESP.
[SwitchC-ipsec-profile-profile002-manual] sa string-key inbound esp simple byebye
[SwitchC-ipsec-profile-profile002-manual] sa string-key outbound esp simple byebye
[SwitchC-ipsec-profile-profile002-manual] quit
4. Apply the IPsec profiles to areas:
# Configure Switch A.
[SwitchA] ospfv3 1
[SwitchA-ospfv3-1] area 1
[SwitchA-ospfv3-1-area-0.0.0.1] enable ipsec-profile profile001
[SwitchA-ospfv3-1-area-0.0.0.1] quit
[SwitchA-ospfv3-1] quit
# Configure Switch B.
[SwitchB] ospfv3 1
[SwitchB-ospfv3-1] area 0
[SwitchB-ospfv3-1-area-0.0.0.0] enable ipsec-profile profile002
[SwitchB-ospfv3-1-area-0.0.0.0] quit
[SwitchB-ospfv3-1] area 1
[SwitchB-ospfv3-1-area-0.0.0.1] enable ipsec-profile profile001
[SwitchB-ospfv3-1-area-0.0.0.1] quit
[SwitchB-ospfv3-1] quit
# Configure Switch C.
[SwitchC] ospfv3 1
[SwitchC-ospfv3-1] area 0
392
[SwitchC-ospfv3-1-area-0.0.0.0] enable ipsec-profile profile002
[SwitchC-ospfv3-1-area-0.0.0.0] quit
[SwitchC-ospfv3-1] quit
Verifying the configuration
# Verify that OSPFv3 packets between Switches A, B, and C are protected by IPsec. (Details not shown.)
393
Configuring IPv6 IS-IS
Overview
IPv6 IS-IS supports all IPv4 IS-IS features except that it advertises IPv6 routing information. This chapter describes only IPv6 IS-IS specific configuration tasks. For information about IS-IS, see
Intermediate System-to-Intermediate System (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), which must be carried in hello packets sent by IPv6 IS-IS.
Configuring basic IPv6 IS-IS
Before you configure basic IPv6 IS-IS, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IPv6 connectivity between neighboring nodes.
•
Enable IS-IS.
Basic IPv6 IS-IS configuration can implement the interconnection of IPv6 networks.
To configure basic IPv6 IS-IS:
Step
1. Enter system view.
Command system-view
2. Enable an IS-IS process and enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure the network entity title (NET) for the IS-IS process.
4. Enable IPv6 for the IS-IS process. network-entity ipv6 enable net
5. Return to system view. quit
6. Enter interface view.
interface interface-type interface-number
7. Enable IPv6 for IS-IS on the interface.
isis ipv6 enable [ process-id ]
Remarks
N/A
By default, no IS-IS process is enabled.
By default, no NET is configured.
The default setting is disabled.
N/A
N/A
By default, IPv6 is disabled for
IS-IS on an interface.
Configuring IPv6 IS-IS route control
Before you configure IPv6 IS-IS route control, complete basic IPv6 IS-IS configuration.
394
To configure IPv6 IS-IS route control:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Specify a preference for
IPv6 IS-IS routes.
4. Configure an IPv6 IS-IS summary route.
5. Generate an IPv6 IS-IS default route.
6. Configure IPv6 IS-IS to filter redistributed routes.
7. Configure IPv6 IS-IS to filter received routes.
8. Configure IPv6 IS-IS to redistribute routes from another routing protocol.
9. Configure the maximum number of redistributed
Level 1/Level 2 IPv6 routes.
10. Configure route advertisement from
Level-2 to Level-1.
11. Configure route advertisement from
Level-1 to Level-2.
12. Specify the maximum number of ECMP routes for load balancing.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ]
Remarks
N/A
N/A ipv6 preference { route-policy route-policy-name | preference } *
ipv6 summary ipv6-prefix prefix-length
[ avoid-feedback | generate_null0_route |
[ level-1 | level-1-2 | level-2 ] | tag tag ] * ipv6 default-route-advertise [ [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name ] *
By default, the default setting is 15.
By default, no IPv6 IS-IS summary route is configured.
By default, no IPv6 default route is generated. ipv6 filter-policy { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } export [ protocol
[ process-id ] ]
By default, IPv6 IS-IS does not filter redistributed routes.
This command is usually used together with the ipv6 import-route command. ipv6 filter-policy { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } import
By default, IPv6 IS-IS does not filter received routes.
ipv6 import-route protocol [ process-id ]
[ allow-ibgp ] [ cost cost | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *
By default, IPv6 IS-IS does not redistribute routes from any other routing protocol.
ipv6 import-route limit number
By default, the maximum number of redistributed
Level 1/Level 2 IPv6 routes is not configured. ipv6 import-route isisv6 level-2 into level-1 [ filter-policy { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] * ipv6 import-route isisv6 level-1 into level-2 [ filter-policy { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] *
By default, IPv6 IS-IS does not advertise routes from
Level-2 to Level-1.
By default, IPv6 IS-IS advertises routes from
Level-1 to Level-2.
ipv6 maximum load-balancing number
By default, the maximum number of IPv6 IS-IS
ECMP routes equals the maximum number of
ECMP routes supported by the system.
Use the max-ecmp-num command to configure the maximum number of
ECMP routes supported by the system. For more information about the max-ecmp-num command, see Layer 3—IP
Routing Command
Reference.
395
Tuning and optimizing IPv6 IS-IS networks
Configuration prerequisites
Before you tune and optimize IPv6 IS-IS networks, complete basic IPv6 IS-IS tasks.
Assigning a convergence priority to IPv6 IS-IS routes
A topology change causes IS-IS routing convergence. To improve convergence speed, you can assign convergence priorities to IPv6 IS-IS routes. Convergence priority levels are critical, high, medium, and low. The higher the convergence priority, the faster the convergence speed.
By default, IPv6 IS-IS host routes have medium convergence priority, and other IPv6 IS-IS routes have low convergence priority.
To assign a convergence priority to specific IPv6 IS-IS routes:
Step
1. Enter system view.
2. Enter IS-IS view.
3. Assign a convergence priority to specific IPv6 IS-IS routes.
Command system-view isis [ process-id ] [ vpn-instance vpn-instance-name ] ipv6 priority { critical | high | medium } { prefix-list prefix-list-name | tag tag-value }
Remarks
N/A
N/A
By default, IPv6 IS-IS routes, except IPv6 IS-IS host routes, have the low convergence priority.
Configuring BFD for IPv6 IS-IS
Bidirectional forwarding detection (BFD) can quickly detect faults between IPv6 IS-IS neighbors to improve the convergence speed of IPv6 IS-IS. For more information about BFD, see High Availability
Configuration Guide .
To configure BFD for IPv6 IS-IS:
Step
1. Enter system view.
Command system-view
2. Enable an IS-IS process and enter IS-IS view.
isis [ process-id ] [ vpn-instance vpn-instance-name ]
3. Configure the NET for the
IS-IS process. network-entity net
4. Enable IPv6 for the IS-IS process. ipv6 enable
5. Return to system view. quit
6. Enter interface view.
interface interface-type interface-number
7. Enable IPv6 for IS-IS on the interface.
isis ipv6 enable [ process-id ]
8. Enable BFD for IPv6 IS-IS. isis ipv6 bfd enable
Remarks
N/A
N/A
By default, no NET is configured.
By default, IPv6 for the IS-IS process is disabled.
N/A
N/A
By default, IPv6 is disabled for
IS-IS on an interface.
By default, BFD for IPv6 IS-IS is disabled.
396
Displaying and maintaining IPv6 IS-IS
Execute display commands in any view. For other display and reset
Task
Display information about routes redistributed by IPv6 IS-IS.
Display IPv6 IS-IS routing information.
Display IPv6 IS-IS topology information.
Command display isis redistribute ipv6 [ ipv6-address mask-length ]
[ level-1 | level-2 ] [ process-id ] display isis route ipv6 [ ipv6-address ] [ [ level-1 | level-2 ] | verbose ] * [ process-id ] display isis spf-tree ipv6 [ [ level-1 | level-2 ] | verbose ] *
[ process-id ]
IPv6 IS-IS configuration examples
IPv6 IS-IS basic configuration example
Network requirements
As shown in Figure 97 , Switch A, Switch B, Switch C, and Switch D, all enabled with IPv6, reside in
the same AS. Configure IPv6 IS-IS on the switches so that they can reach each other.
Switch A and Switch B are Level-1 switches, Switch D is a Level-2 switch, and Switch C is a
Level-1-2 switch.
Figure 97 Network diagram
Vlan-int100
2001:1::2/64
Switch A
L1
Vlan-int100
2001:1::1/64
Vlan-int200
2001:2::1/64
Switch C
L1/L2
Vlan-int300
2001:3::1/64
Vlan-int300
2001:3::2/64
Switch D
L2
Vlan-int301
2001:4::1/64
Vlan-int200
2001:2::2/64
Area 20
Switch B
L1
Area 10
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] is-level level-1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] ipv6 enable
[SwitchA-isis-1] quit
397
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] isis ipv6 enable 1
[SwitchA-Vlan-interface100] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis 1
[SwitchB-isis-1] is-level level-1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] ipv6 enable
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] isis ipv6 enable 1
[SwitchB-Vlan-interface200] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] ipv6 enable
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 100
[SwitchC-Vlan-interface100] isis ipv6 enable 1
[SwitchC-Vlan-interface100] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis ipv6 enable 1
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 300
[SwitchC-Vlan-interface300] isis ipv6 enable 1
[SwitchC-Vlan-interface300] quit
# Configure Switch D.
<SwitchD> system-view
[SwitchD] isis 1
[SwitchD-isis-1] is-level level-2
[SwitchD-isis-1] network-entity 20.0000.0000.0004.00
[SwitchD-isis-1] ipv6 enable
[SwitchD-isis-1] quit
[SwitchD] interface vlan-interface 300
[SwitchD-Vlan-interface300] isis ipv6 enable 1
[SwitchD-Vlan-interface300] quit
[SwitchD] interface vlan-interface 301
[SwitchD-Vlan-interface301] isis ipv6 enable 1
[SwitchD-Vlan-interface301] quit
Verifying the configuration
# Display the IPv6 IS-IS routing table on Switch A.
[SwitchA] display isis route ipv6
Route information for IS-IS(1)
------------------------------
398
Level-1 IPv6 Forwarding Table
-----------------------------
Destination : :: PrefixLen: 0
Flag : R/-/- Cost : 10
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan100
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100
Destination : 2001:3:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Switch B.
[SwitchB] 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: Vlan200
Destination : 2001:1:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan200
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : Direct Interface: Vlan200
Destination : 2001:3:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan200
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Switch C.
[SwitchC] display isis route ipv6
399
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: Vlan100
Destination : 2001:2:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan200
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan300
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
Next Hop : Direct Interface: Vlan100
Destination : 2001:2:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan200
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan300
Destination : 2001:4::1 PrefixLen: 128
Flag : R/-/- Cost : 10
Next Hop : FE80::20F:E2FF:FE3E:FA3D Interface: Vlan300
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display the IPv6 IS-IS routing table on Switch D.
[SwitchD] display isis route ipv6
Route information for IS-IS(1)
------------------------------
Level-2 IPv6 Forwarding Table
400
-----------------------------
Destination : 2001:1:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan300
Destination : 2001:2:: PrefixLen: 64
Flag : R/-/- Cost : 20
Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan300
Destination : 2001:3:: PrefixLen: 64
Flag : D/L/- Cost : 10
Next Hop : Direct Interface: Vlan300
Destination : 2001:4::1 PrefixLen: 128
Flag : D/L/- Cost : 0
Next Hop : Direct Interface: Loop1
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
BFD for IPv6 IS-IS configuration example
Network requirements
•
Configure IPv6 IS-IS on Switch A and Switch B so that they can reach other.
•
Enable BFD on VLAN-interface 10 of Switch A and Switch B.
After the link between Switch B and the Layer-2 switch fails, BFD can quickly detect the failure and notify IPv6 IS-IS of the failure. Then Switch A and Switch B communicate through Switch C.
Figure 98 Network diagram
2001:1::/64
Switch A
Vlan-int10
Vlan-int11
BFD
L2 Switch
Vlan-int10
Switch B
2001:4::/64
Vlan-int13
Area 0
Vlan-int11 Vlan-int13
Switch C
Table 22 Interface and IP address assignment
Device
Switch A
Switch A
Switch B
Interface
Vlan-int10
Vlan-int11
Vlan-int10
401
IPv6 address
2001::1/64
2001:2::1/64
2001::2/64
Device
Switch B
Switch C
Interface
Vlan-int13
Vlan-int11
IPv6 address
2001:3::2/64
2001:2::2/64
Switch C Vlan-int13
Configuration procedure
1. Configure IPv6 addresses for interfaces. (Details not shown.)
2. Configure IPv6 IS-IS:
# Configure Switch A.
<SwitchA> system-view
[SwitchA] isis 1
[SwitchA-isis-1] is-level level-1
[SwitchA-isis-1] network-entity 10.0000.0000.0001.00
[SwitchA-isis-1] ipv6 enable
[SwitchA-isis-1] quit
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] isis ipv6 enable 1
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 11
[SwitchA-Vlan-interface11] isis ipv6 enable 1
[SwitchA-Vlan-interface11] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis 1
[SwitchB-isis-1] is-level level-1
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] ipv6 enable
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] isis ipv6 enable 1
[SwitchB-Vlan-interface10] quit
[SwitchB] interface vlan-interface 13
[SwitchB-Vlan-interface13] isis ipv6 enable 1
[SwitchB-Vlan-interface13] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis 1
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00
[SwitchC-isis-1] ipv6 enable
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 11
[SwitchC-Vlan-interface11] isis ipv6 enable 1
[SwitchC-Vlan-interface11] quit
[SwitchC] interface vlan-interface 13
[SwitchC-Vlan-interface13] isis ipv6 enable 1
[SwitchC-Vlan-interface13] quit
3. Configure BFD functions:
2001:3::1/64
402
# Enable BFD and configure BFD parameters on Switch A.
[SwitchA] bfd session init-mode active
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] isis ipv6 bfd enable
[SwitchA-Vlan-interface10] bfd min-transmit-interval 500
[SwitchA-Vlan-interface10] bfd min-receive-interval 500
[SwitchA-Vlan-interface10] bfd detect-multiplier 7
[SwitchA-Vlan-interface10] return
# Enable BFD and configure BFD parameters on Switch B.
[SwitchB] bfd session init-mode active
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] isis ipv6 bfd enable
[SwitchB-Vlan-interface10] bfd min-transmit-interval 500
[SwitchB-Vlan-interface10] bfd min-receive-interval 500
[SwitchB-Vlan-interface10] bfd detect-multiplier 6
Verifying the configuration
# Display BFD session information on Switch A.
<SwitchA> display bfd session
Total Session Num: 1 Init Mode: Active
IPv6 Session Working Under Ctrl Mode:
Local Discr: 1441 Remote Discr: 1450
Source IP: FE80::20F:FF:FE00:1202 (link-local address of VLAN-interface 10 on
Switch A)
Destination IP: FE80::20F:FF:FE00:1200 (link-local address of VLAN-interface 10 on
Switch B)
Session State: Up Interface: Vlan10
Hold Time: 2319ms
# Display routes destined for 2001:4::0/64 on Switch A.
<SwitchA> display ipv6 routing-table 2001:4::0 64
Summary Count : 1
Destination: 2001:4::/64 Protocol : ISISv6
NextHop : FE80::20F:FF:FE00:1200 Preference: 15
Interface : Vlan10 Cost : 10
The output shows that Switch A and Switch B communicate through VLAN-interface 10. Then the link over VLAN-interface 10 fails.
# Display routes destined for 2001:4::0/64 on Switch A.
<SwitchA> display ipv6 routing-table 2001:4::0 64
Summary Count : 1
Destination: 2001:4::/64 Protocol : ISISv6
NextHop : FE80::BAAF:67FF:FE27:DCD0 Preference: 15
Interface : Vlan11 Cost : 20
403
The output shows that Switch A and Switch B communicate through VLAN-interface 11.
404
Configuring IPv6 PBR
Overview
Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop for packets that match specific criteria such as ACLs.
A device forwards received packets using the following process:
1. The device uses PBR to forward matching packets.
2. If the packets do not match the PBR policy or the PBR-based forwarding fails, the device uses the routing table, excluding the default route, to forward the packets.
3. If the routing table-based forwarding fails, the device uses the default next hop or default output interface defined in PBR to forward packets.
4. If the default next hop or default output interface-based forwarding fails, the device uses the default route to forward packets.
PBR includes local PBR and interface PBR.
•
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.
•
A node has a match mode of permit or deny .
An IPv6 policy matches nodes in priority order against packets. 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, it is forwarded according to the routing table. if-match clause
IPv6 PBR supports the if-match acl clause to set an ACL match criterion. You can specify only one if-match acl clause for a node. apply clause
IPv6 PBR supports the apply next-hop clause to set next hops for packets.
405
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 is configured with an apply clause, IPv6 PBR executes the apply clause on the node. It does not match the packet against the next node.
•
If the node is configured with no apply clause, the packet is forwarded according to the routing table.
In deny mode
The packet is forwarded according to the routing table.
No
IPv6 PBR matches the packet against the next node.
A node that has no if-match clauses matches any packet.
IPv6 PBR matches the packet against the next node.
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 next hop.
•
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 .
IPv6 PBR configuration task list
Tasks at a glance
(Required.) Configuring an IPv6 policy :
•
•
Configuring match criteria for an IPv6 node
•
Configuring actions for an IPv6 node
(Required.) Configuring IPv6 PBR :
•
•
Configuring IPv6 interface PBR
Configuring an IPv6 policy
Creating an IPv6 node
Step
1. Enter system view.
Command system-view
Remarks
N/A
406
Step
2. Create an IPv6 policy or policy node, and enter IPv6 policy node view.
Command ipv6 policy-based-route policy-name [ deny | permit ] node node-number
Configuring match criteria for an IPv6 node
Remarks
By default, no IPv6 policy node is created.
Step Command
1. Enter system view. system-view
2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number
Remarks
N/A
N/A
3. Configure an ACL match criterion. if-match acl { acl6-number | name acl6-name }
By default, no ACL match criterion is configured.
NOTE:
An ACL match criterion uses the specified ACL to match packets regardless of the permit or deny action and the time range of the ACL. If the specified ACL does not exist, no packet can match the criterion.
Configuring actions for an IPv6 node
Step
1. Enter system view.
2. Enter IPv6 policy node view.
Command system-view ipv6 policy-based-route policy-name
[ deny | permit ] node node-number
Remarks
N/A
3. Set next hops for permitted IPv6 packets. apply next-hop [ vpn-instance vpn-instance-name ] { ipv6-address
[ direct ] [ track track-entry-number ] }&<1n >
N/A
By default, no next hop is specified.
You can specify multiple next hops for backup by executing this command once or multiple times.
You can specify a maximum of two next hops for a node.
Configuring IPv6 PBR
Configuring IPv6 local PBR
Configure IPv6 PBR by applying a policy locally. IPv6 PBR uses the policy to guide the forwarding of locally generated packets. The specified policy must already exist. Otherwise, the IPv6 local PBR configuration fails.
You can apply only one policy locally. 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. Do not configure IPv6 local PBR unless doing so is required.
407
To configure IPv6 local PBR:
Step
1. Enter system view.
2. Apply a policy locally.
Command system-view ipv6 local policy-based-route policy-name
Remarks
N/A
By default, no policy is locally applied.
Configuring IPv6 interface PBR
Configure IPv6 PBR by applying an IPv6 policy to an interface. IPv6 PBR uses the policy to guide the forwarding of IPv6 packets received on the interface. The specified policy must already exist.
Otherwise, the IPv6 interface PBR configuration fails.
You can apply only one policy to an interface. Before you apply a new policy, you must first remove the current policy from the interface.
You can apply a policy to multiple interfaces.
To configure IPv6 interface PBR:
Step Command
1. Enter system view. system-view
2. Enter interface view.
Remarks
N/A interface interface-type interface-number N/A
3. Apply an IPv6 policy to the interface. ipv6 policy-based-route policy-name
By default, no IPv6 policy is applied to the interface.
Displaying and maintaining IPv6 PBR
Execute display commands in any view and reset commands in user view.
Task
Display IPv6 PBR policy information.
Display IPv6 PBR configuration.
Display IPv6 local PBR configuration and statistics.
Display IPv6 interface PBR configuration and statistics.
Clear IPv6 PBR statistics.
Command display ipv6 policy-based-route [ policy policy-name ] display ipv6 policy-based-route setup display ipv6 policy-based-route local [ slot slot-number ] display ipv6 policy-based-route interface interface-type interface-number [ slot slot-number ] reset ipv6 policy-based-route statistics [ policy
policy-name ]
408
IPv6 PBR configuration examples
Packet type-based IPv6 local PBR configuration example
Network requirements
As shown in Figure 99 , configure IPv6 PBR on Switch A to forward all TCP packets to the next hop
1::2. Switch A forwards other packets according to the routing table.
Figure 99 Network diagram
Switch A
Vlan-int10
1::1/64
Vlan-int10
1::2/64
Switch B
Vlan-int20
2::1/64
Vlan-int20
2::2/64
Switch C
Configuration procedure
1. Configure Switch A:
# Create VLAN 10 and VLAN 20.
<SwitchA> system-view
[SwitchA] vlan 10
[SwitchA-vlan10] quit
[SwitchA] vlan 20
[SwitchA-vlan20] quit
# Configure the IPv6 addresses of VLAN-interface 10 and VLAN-interface 20.
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ipv6 address 1::1 64
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 20
[SwitchA-Vlan-interface20] ipv6 address 2::1 64
[SwitchA-Vlan-interface20] quit
# Configure ACL 3001 to match TCP packets.
[SwitchA] acl ipv6 number 3001
[SwitchA-acl6-adv-3001] rule permit tcp
[SwitchA-acl6-adv-3001] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1::2.
[SwitchA] ipv6 policy-based-route aaa permit node 5
[SwitchA-pbr6-aaa-5] if-match acl 3001
[SwitchA-pbr6-aaa-5] apply next-hop 1::2
[SwitchA-pbr6-aaa-5] quit
# Configure IPv6 local PBR by applying policy aaa to Switch A.
[SwitchA] ipv6 local policy-based-route aaa
2. Configure Switch B:
# Create VLAN 10.
<SwitchB> system-view
[SwitchB] vlan 10
[SwitchB-vlan10] quit
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# Configure the IPv6 address of VLAN-interface 10.
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ipv6 address 1::2 64
3. Configure Switch C:
# Create VLAN 20.
<SwitchC> system-view
[SwitchC] vlan 20
[SwitchC-vlan20] quit
# Configure the IPv6 address of VLAN-interface 20.
[SwitchC] interface vlan-interface 20
[SwitchC-Vlan-interface20] ipv6 address 2::2 64
Verifying the configuration
# Telnet to Switch B on Switch A. The operation succeeds.
# Telnet to Switch C on Switch A. The operation fails.
# Ping Switch C from Switch A. The operation succeeds.
Telnet uses TCP, and ping uses ICMP. The results show the following:
•
All TCP packets sent from Switch A are forwarded to the next hop 1::2.
•
Other packets are forwarded through VLAN-interface 20.
•
The IPv6 local PBR configuration is effective.
Packet type-based IPv6 interface PBR configuration example
Network requirements
As shown in Figure 100 , configure IPv6 PBR on Switch A to forward all TCP packets received on
VLAN-interface 11 to the next hop 1::2. Switch A forwards other IPv6 packets according to the routing table.
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Figure 100 Network diagram
Switch B Switch C
Vlan-int10
1::2/64
Vlan-int20
2::2/64
Vlan-int10
1::1/64
Switch A
Vlan-int20
2::1/64
Vlan-int11
10::2/64
Subnet
10::1/64
Host A
10::3/64
Gateway: 10::2/64
Host B
Configuration procedure
1. Configure Switch A:
# Create VLAN 10 and VLAN 20.
<SwitchA> system-view
[SwitchA] vlan 10
[SwitchA-vlan10] quit
[SwitchA] vlan 20
[SwitchA-vlan20] quit
# Configure RIPng.
[SwitchA] ripng 1
[SwitchA-ripng-1] quit
[SwitchA] interface vlan-interface 10
[SwitchA-Vlan-interface10] ipv6 address 1::1 64
[SwitchA-Vlan-interface10] ripng 1 enable
[SwitchA-Vlan-interface10] quit
[SwitchA] interface vlan-interface 20
[SwitchA-Vlan-interface20] ipv6 address 2::1 64
[SwitchA-Vlan-interface20] ripng 1 enable
[SwitchA-Vlan-interface20] quit
# Configure ACL 3001 to match TCP packets.
[SwitchA] acl ipv6 number 3001
[SwitchA-acl6-adv-3001] rule permit tcp
[SwitchA-acl6-adv-3001] quit
# Configure Node 5 for policy aaa to forward TCP packets to next hop 1::2.
[SwitchA] ipv6 policy-based-route aaa permit node 5
[SwitchA-pbr6-aaa-5] if-match acl 3001
[SwitchA-pbr6-aaa-5] apply next-hop 1::2
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[SwitchA-pbr6-aaa-5] quit
# Configure IPv6 interface PBR by applying policy aaa to VLAN-interface 11.
[SwitchA] interface vlan-interface 11
[SwitchA-Vlan-interface11] ipv6 address 10::2 64
[SwitchA-Vlan-interface11] undo ipv6 nd ra halt
[SwitchA-Vlan-interface11] ripng 1 enable
[SwitchA-Vlan-interface11] ipv6 policy-based-route aaa
2. Configure Switch B:
# Create VLAN 10.
<SwitchB> system-view
[SwitchB] vlan 10
[SwitchB-vlan10] quit
# Configure RIPng.
[SwitchB] ripng 1
[SwitchB-ripng-1] quit
[SwitchB] interface vlan-interface 10
[SwitchB-Vlan-interface10] ipv6 address 1::2 64
[SwitchB-Vlan-interface10] ripng 1 enable
[SwitchB-Vlan-interface10] quit
3. Configure Switch C:
# Create VLAN 20.
<SwitchC> system-view
[SwitchC] vlan 20
[SwitchC-vlan20] quit
# Configure RIPng.
[SwitchC] ripng 1
[SwitchC-ripng-1] quit
[SwitchC] interface vlan-interface 20
[SwitchC-Vlan-interface20] ipv6 address 2::2 64
[SwitchC-Vlan-interface20] ripng 1 enable
[SwitchC-Vlan-interface20] quit
Verifying the configuration
# Enable IPv6 and configure the IPv6 address 10::3 for Host A.
C:\>ipv6 install
Installing...
Succeeded.
C:\>ipv6 adu 4/10::3
# On Host A, Telnet to Switch B that is directly connected to Switch A. The operation succeeds.
# On Host A, Telnet to Switch C that is directly connected to Switch A. The operation fails.
# Ping Switch C from Host A. The operation succeeds.
Telnet uses TCP, and ping uses ICMP. The results show the following:
•
All TCP packets arriving on VLAN-interface 11 of Switch A are forwarded to next hop 1::2.
•
Other packets are forwarded through VLAN-interface 20.
•
The IPv6 interface PBR configuration is effective.
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Configuring routing policies
Overview
Routing policies control routing paths by filtering and modifying routing information. This chapter describes both IPv4 and IPv6 routing policies.
Routing policies can filter advertised, received, and redistributed routes, and modify attributes for specific routes.
To configure a routing policy:
1. Configure filters based on route attributes, such as destination address and the advertising router's address.
2. Create a routing policy and apply filters to the routing policy.
Filters
Routing policies can use the following filters to match routes.
ACL
ACLs include IPv4 ACLs and IPv6 ACLs. 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
IP prefix lists include IPv4 prefix lists and IPv6 prefix lists.
An IP prefix list matches the destination address of routes. You can use the gateway option to receive routes only from specific routers. For more information about the gateway option, see
An IP prefix list, identified by name, can contain multiple items. Each item, identified by an index number, specifies a prefix range to match. An item with a smaller index number is matched first. A route that matches one item matches the IP prefix list.
AS path list
An AS path list matches the AS_PATH attribute of BGP routes.
For more information about AS path lists, see " Configuring BGP ."
Community list
A community list matches the COMMUNITY attribute of BGP routes.
For more information about community lists, see " Configuring BGP ."
Extended community list
An extended community list matches the extended community attribute (Route-Target for VPN) of
BGP routes.
For more information about extended community lists, see MPLS Configuration Guide .
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 (except the route configured with the continue clauses) that matches one node matches the routing policy.
413
Each node has a match mode of permit or deny .
• permit —Specifies the permit match mode for a routing policy node. If a route matches all the if-match clauses of the node, it is handled by the apply clauses of the node. The route does not match against the next node unless the continue clause is configured. If a route does not match all the if-match clauses of the node, it matches against the next node.
• deny —Specifies the deny match mode for a routing policy node. The apply and continue clauses of a deny-mode node are never executed. If a route matches all the if-match clauses of the node, it is discarded and does not match against the next node. If a route does not match all the if-match clauses of the node, it matches against the next node.
A node can contain a set of if-match , apply , and continue clauses.
• if-match clauses—Configure the match criteria that match the attributes of routes. The if-match clauses are in a logical AND relationship. A route must match 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-mode 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.
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-mode node, the node will permit all routes.
•
Configure a permit-mode node containing no if-match or apply clauses behind multiple deny-mode nodes to allow unmatched routes to pass.
Configuring filters
Configuration prerequisites
Determine the IP prefix list name, matching address range, and community list number.
Configuring an IP prefix list
Configuring an IPv4 prefix list
If all the items are set to deny mode, no routes can pass the IPv4 prefix list. To allow unmatched IPv4 routes to pass, you must configure the permit 0.0.0.0 0 less-equal 32 item following multiple deny items.
To configure an IPv4 prefix list:
Step Command
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 ]
Remarks
N/A
By default, no IPv4 prefix list is configured.
414
Configuring an IPv6 prefix list
If all items are set to deny mode, no routes can pass the IPv6 prefix list. To allow unmatched IPv6 routes to pass, you must configure the permit :: 0 less-equal 128 item following multiple deny items.
To configure an IPv6 prefix list:
Step Command
1. Enter system view. system-view
2. Configure an IPv6 prefix list.
•
Method 1:
ipv6 prefix-list prefix-list-name [ index index-number ] { deny | permit } ipv6-address prefix-length [ greater-equal min-prefix-length ]
[ less-equal max-prefix-length ]
•
Method 2: ipv6 prefix-list prefix-list-name [ index index-number ] { deny | permit } ipv6-address
inverse prefix-length
Remarks
N/A
By default, no IPv6 prefix list is configured.
When the inverse keyword is specified, an
IPv6 prefix is matched from the least significant bit to the most significant bit.
Configuring an AS path list
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 that matches one item matches the AS path list.
To configure an AS path list:
Step
1. Enter system view.
2. Configure an AS path list.
Command system-view
ip as-path as-path-number { deny | permit } regular-expression
Remarks
N/A
By default, no AS path list is configured.
Configuring a community list
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 that matches one item matches the community list.
To configure a community list:
Step
1. Enter system view.
2. Configure a community list.
Command Remarks system-view
•
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
N/A
By default, no community list is configured.
415
Configuring an extended community list
You can configure multiple items for an extended community list that is identified by a number. The relationship between the items is logical OR. A route that matches one item matches the extended community list.
To configure an extended community list:
Step
1. Enter system view.
2. Configure an extended community list.
Command system-view ip extcommunity-list ext-comm-list-number
{ deny | permit } { rt route-target }&<1-32>
Remarks
N/A
By default, no extended community list is configured.
Configuring a routing policy
Configuration prerequisites
Configure filters and routing protocols, and determine the routing policy name, node numbers, match criteria, and the attributes to be modified.
Creating a routing policy
For a routing policy that has more than one node, configure at least one permit-mode node. A route that does not match any node cannot pass the routing policy. If all the nodes are in deny mode, no routes can pass the routing policy.
To create a routing policy:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Create a routing policy and a node, and enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number
By default, no routing policy is created.
Configuring if-match clauses
You can either specify no if-match clauses or multiple if-match clauses for a routing policy node. If no if-match clauses are specified for a permit-mode node, all routes can pass the node. If no if-match clauses are specified for a deny-mode node, no routes can pass the node.
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 identical if-match clauses are generated. These clauses have a logical OR relationship. A route only needs to match one of them.
To configure if-match clauses:
Step
1. Enter system view.
Command system-view
Remarks
N/A
416
Step
2. Enter routing policy node view.
3. Match routes whose destination, next hop, or source matches an ACL or prefix list.
Command Remarks route-policy route-policy-name
{ deny | permit } node node-number
•
Match IPv4 routes whose destination, next hop, or source matches an ACL or IPv4 prefix list: if-match ip { address | next-hop | route-source } { acl acl-number | prefix-list prefix-list-name }
•
Match IPv6 routes whose destination, next hop, or source matches an ACL or IPv6 prefix list: if-match ipv6 { address | next-hop | route-source } { acl acl6-number | prefix-list prefix-list-name }
N/A
By default, no ACL or prefix list match criterion is configured.
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 match rules are inactive, the clause is not matched.
The ACL specified in an if-match clause must be a non-VPN ACL.
4. Match BGP routes whose
AS_PATH attribute matches a specified AS path list. if-match as-path as-path-number &<1-32>
By default, no AS path match criterion is configured.
5. 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
>
By default, no COMMUNITY match criterion is matched.
6. Match routes having the specified cost.
7. Match BGP routes whose extended community attribute matches a specified extended community list.
if-match cost value if-match extcommunity ext-comm-list-number &<1-32>
By default, no cost match criterion is configured.
By default, no extended community list match criterion is configured.
8. Match routes having the specified output interface.
9. Match BGP routes having the specified local preference.
10. Match routes having MPLS labels.
11. Match routes having the specified route type.
12. Match IGP routes having the specified tag value.
if-match interface interface-number if-match local-preference
preference
{ if-match mpls-label interface-type
}&<1-16>
By default, no output interface match criterion is configured.
This command is not supported by BGP.
By default, no local preference is configured for
BGP routes.
By default, no MPLS label match criterion is configured. if-match route-type
{ external-type1 | external-type1or2 | external-type2
| internal | is-is-level-1 | is-is-level-2 | nssa-external-type1 | nssa-external-type1or2 | nssa-external-type2 } *
By default, no route type match criterion is configured.
if-match tag value
By default, no tag match criterion is configured.
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Configuring apply clauses
Except for the apply commands used for setting the next hop for IPv4 and IPv6 routes, all apply commands are the same for IPv4 and IPv6 routing.
To configure apply clauses:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2.
3. Set the AS_PATH attribute for
BGP routes.
4. Delete the specified
COMMUNITY attribute for
BGP routes.
5.
6.
7.
Enter routing policy node view.
Set the specified
COMMUNITY attribute for
BGP routes.
Set a cost for routes.
Set a cost type for routes. route-policy route-policy-name { deny | permit } node node-number
N/A apply as-path as-number &<1-32> [ replace ]
By default, no AS_PATH attribute is set for BGP routes. apply comm-list
{ comm-list-number | comm-list-name } delete
By default, no COMMUNITY attribute is deleted for BGP routes. apply community { none | additive |
{ community-number &<1-32> | aa:nn &<1-32> | internet | no-advertise | no-export | no-export-subconfed } *
[ additive ] }
By default, no community attribute is set for BGP routes. apply cost [ + | - ] value apply cost-type { external | internal | type-1 | type-2 }
By default, no cost is set for routes.
By default, no cost type is set for routes.
8.
9.
Set the extended community attribute for BGP routes.
Set the next hop for routes. apply extcommunity { rt route-target }&<1-32>
[ additive ]
•
Set the next hop for IPv4 routes: apply ip-address next-hop ip-address
[ public | vpn-instance vpn-instance-name ]
•
Set the next hop for IPv6 routes: apply ipv6 next-hop
ipv6-address
By default, no extended community attribute is set for BGP routes.
By default, no next hop is set for
IPv4/IPv6 routes.
The apply ip-address next-hop and apply ipv6 next-hop commands do not apply to redistributed IPv4 and IPv6 routes.
10. Redistribute routes to a specified IS-IS level. apply isis
| level-2 }
{ level-1 | level-1-2
By default, routes are not redistributed into a specified IS-IS level.
11. Set a local preference for BGP routes. apply local-preference
preference
12. Set MPLS labels. apply mpls-label
13. Set the ORIGIN attribute for
BGP routes. apply origin
| igp |
{ egp incomplete } as-number
By default, no local preference is set for BGP routes.
By default, no MPLS label is set.
By default, no ORIGIN attribute is set for BGP routes.
14. Set a preference. apply preference preference By default, no preference is set.
15. Set a preferred value for BGP routes. apply preferred-value
preferred-value
By default, no preferred value is set for BGP routes.
418
Step
16. Set a prefix priority.
Command Remarks apply prefix-priority { critical
| high | medium }
By default, no prefix priority is set, which means the prefix priority is low.
17. Set a tag value for IGP routes. apply tag value
By default, no tag value is set for
IGP routes.
18. Set a backup link for fast reroute (FRR).
•
Set an IPv4 backup link for FRR: apply fast-reroute
{ backup-interface interface-type interface-number
[ backup-nexthop ip-address ] | backup-nexthop ip-address }
•
Set an IPv6 backup link for FRR: apply ipv6 fast-reroute backup-nexthop ipv6-address
By default, no backup link is set for
FRR.
Configuring the continue clause
Follow these guidelines when you configure the continue clause to combine multiple nodes:
•
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:
ï‚¡
ï‚¡ apply as-path without the replace keyword. apply cost with the + or – keyword.
ï‚¡ apply community with the additive keyword.
ï‚¡ 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.
To configure the continue clause:
Step
1. Enter system view.
2. Enter routing policy node view.
Command system-view route-policy route-policy-name
{ deny | permit } node node-number
Remarks
N/A
N/A
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.
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Displaying and maintaining the routing policy
Execute display commands in any view and reset commands in user view.
Task
Display BGP AS path list information.
Display BGP community list information.
Display BGP extended community list information.
Display IPv4 prefix list statistics.
Display IPv6 prefix list statistics.
Display routing policy information.
Clear IPv4 prefix list statistics.
Clear IPv6 prefix list statistics.
Command display ip as-path [ as-path-number ] display ip community-list [ basic-community-list-number | adv-community-list-number | name comm-list-name ] display ip extcommunity-list [ ext-comm-list-number ] display ip prefix-list [ name prefix-list-name ] display ipv6 prefix-list [ name prefix-list-name ] display route-policy [ name route-policy-name ] reset ip prefix-list [ prefix-list-name ] reset ipv6 prefix-list [ prefix-list-name ]
Routing policy configuration examples
Routing policy configuration example for IPv4 route redistribution
Network requirements
As shown in Figure 101 , Switch B exchanges routing information with Switch A by using OSPF and
with Switch C by using IS-IS.
On Switch B, enable route redistribution from IS-IS to OSPF, and 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.
Figure 101 Network diagram
OSPF
IS-IS
Vlan-int100
192.168.1.2/24
Switch B
Vlan-int200
192.168.2.2/24
Vlan-int201
172.17.1.1/24
Vlan-int100
192.168.1.1/24
Vlan-int200
192.168.2.1/24
Vlan-int202
172.17.2.1/24
Switch A Switch C
Vlan-int203
172.17.3.1/24
Configuration procedure
1. Specify IP addresses for interfaces. (Details not shown.)
2. Configure IS-IS:
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# Configure Switch C.
<SwitchC> system-view
[SwitchC] isis
[SwitchC-isis-1] is-level level-2
[SwitchC-isis-1] network-entity 10.0000.0000.0001.00
[SwitchC-isis-1] quit
[SwitchC] interface vlan-interface 200
[SwitchC-Vlan-interface200] isis enable
[SwitchC-Vlan-interface200] quit
[SwitchC] interface vlan-interface 201
[SwitchC-Vlan-interface201] isis enable
[SwitchC-Vlan-interface201] quit
[SwitchC] interface vlan-interface 202
[SwitchC-Vlan-interface202] isis enable
[SwitchC-Vlan-interface202] quit
[SwitchC] interface vlan-interface 203
[SwitchC-Vlan-interface203] isis enable
[SwitchC-Vlan-interface203] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] isis
[SwitchB-isis-1] is-level level-2
[SwitchB-isis-1] network-entity 10.0000.0000.0002.00
[SwitchB-isis-1] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] isis enable
[SwitchB-Vlan-interface200] quit
3. Configure OSPF and route redistribution:
# Configure OSPF on Switch A.
<SwitchA> system-view
[SwitchA] ospf
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] quit
# On Switch B, configure OSPF and enable route redistribution from IS-IS.
[SwitchB] ospf
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] import-route isis 1
[SwitchB-ospf-1] quit
# Display the OSPF routing table on Switch A to view redistributed routes.
[SwitchA] display ospf routing
OSPF Process 1 with Router ID 192.168.1.1
Routing Tables
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Routing for Network
Destination Cost Type NextHop AdvRouter Area
192.168.1.0/24 1 Stub 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:
# Configure ACL 2002 to permit route 172.17.2.0/24.
[SwitchB] acl number 2002
[SwitchB-acl-basic-2002] rule permit source 172.17.2.0 0.0.0.255
[SwitchB-acl-basic-2002] quit
# Configure IP prefix list prefix-a to permit route 172.17.1.0/24.
[SwitchB] ip prefix-list prefix-a index 10 permit 172.17.1.0 24
5. Configure a routing policy.
[SwitchB] route-policy isis2ospf permit node 10
[SwitchB-route-policy-isis2ospf-10] if-match ip address prefix-list prefix-a
[SwitchB-route-policy-isis2ospf-10] apply cost 100
[SwitchB-route-policy-isis2ospf-10] quit
[SwitchB] route-policy isis2ospf permit node 20
[SwitchB-route-policy-isis2ospf-20] if-match ip address acl 2002
[SwitchB-route-policy-isis2ospf-20] apply tag 20
[SwitchB-route-policy-isis2ospf-20] quit
[SwitchB] route-policy isis2ospf permit node 30
[SwitchB-route-policy-isis2ospf-30] quit
6. Apply the routing policy to route redistribution:
# On Switch B, enable route redistribution from IS-IS and apply the routing policy.
[SwitchB] ospf
[SwitchB-ospf-1] import-route isis 1 route-policy isis2ospf
[SwitchB-ospf-1] quit
# Display the OSPF routing table on Switch A.
[SwitchA] 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
422
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.
Routing policy configuration example for IPv6 route redistribution
Network requirements
•
Run RIPng on Switch A and Switch B.
•
On Switch A, configure three static routes. Apply a routing policy to static route redistribution to permit routes 20::/32 and 40::/32 and deny route 30::/32.
Figure 102 Network diagram
20::/32
30::/32
40::/32
Vlan-int200
11::1/32
Vlan-int100
10::1/32
Vlan-int100
10::2/32
Switch A Switch B
Configuration procedure
1. Configure Switch A:
# Configure IPv6 addresses for VLAN-interface 100 and VLAN-interface 200.
<SwitchA> system-view
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ipv6 address 10::1 32
[SwitchA-Vlan-interface100] quit
[SwitchA] interface vlan-interface 200
[SwitchA-Vlan-interface200] ipv6 address 11::1 32
[SwitchA-Vlan-interface200] quit
# Enable RIPng on VLAN-interface 100.
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ripng 1 enable
[SwitchA-Vlan-interface100] quit
# Configure three static routes with next hop 11::2, and make sure the static routes are active.
[SwitchA] ipv6 route-static 20:: 32 11::2
[SwitchA] ipv6 route-static 30:: 32 11::2
[SwitchA] ipv6 route-static 40:: 32 11::2
# Configure a routing policy.
[SwitchA] ipv6 prefix-list a index 10 permit 30:: 32
[SwitchA] route-policy static2ripng deny node 0
[SwitchA-route-policy-static2ripng-0] if-match ipv6 address prefix-list a
423
[SwitchA-route-policy-static2ripng-0] quit
[SwitchA] route-policy static2ripng permit node 10
[SwitchA-route-policy-static2ripng-10] quit
# Enable RIPng and apply the routing policy to static route redistribution.
[SwitchA] ripng
[SwitchA-ripng-1] import-route static route-policy static2ripng
2. Configure Switch B:
# Configure the IPv6 address for VLAN-interface 100.
<SwitchB> system-view
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ipv6 address 10::2 32
# Enable RIPng.
[SwitchB] ripng
[SwitchB-ripng-1] quit
# Enable RIPng on VLAN-interface 100.
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ripng 1 enable
[SwitchB-Vlan-interface100] quit
Verifying the configuration
# Display the RIPng routing table on Switch B.
[SwitchB] display ripng 1 route
Route Flags: A - Aging, S - Suppressed, G - Garbage-collect
----------------------------------------------------------------
Peer FE80::7D58:0:CA03:1 on Vlan-interface 100
Destination 10::/32,
via FE80::7D58:0:CA03:1, cost 1, tag 0, A, 18 secs
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
424
Document conventions and icons
Conventions
This section describes the conventions used in the documentation.
Port numbering in examples
The port numbers in this document are for illustration only and might be unavailable on your device.
Command conventions
Convention
Boldface
Italic
[ ]
{ x | y | ... }
[ x | y | ... ]
{ x | y | ... } *
[ x | y | ... ] *
&<1-n>
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.
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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. #
GUI conventions
Convention
Boldface
Symbols
>
Description
Window names, button names, field names, and menu items are in Boldface. For example, the New User window appears; click OK .
Multi-level menus are separated by angle brackets. For example, File > Create >
Folder .
Convention
WARNING!
CAUTION:
IMPORTANT:
NOTE:
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.
TIP:
425
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 card, such as a firewall, load balancing, NetStream, SSL VPN,
IPS, or ACG card.
426
Support and other resources
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•
To access documentation and support services, go to the Hewlett Packard Enterprise Support
Center website: www.hpe.com/support/hpesc
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•
Technical support registration number (if applicable)
•
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•
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•
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:
ï‚¡ Hewlett Packard Enterprise Support Center Get connected with updates page: www.hpe.com/support/e-updates
ï‚¡
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.
427
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
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429
Index
Numerics
4-byte
IPv4 BGP AS number suppression, 231
6PE
IPv6 BGP AS number suppression, 231
IP routing BGP 6PE basics, 252
IP routing BGP 6PE optional capabilities, 253
A
ABR
OSPF discard route configuration, 75
OSPF route summarization (ABR), 74
OSPFv3 route summarization (ABR), 353
ACL
action
address
IP routing MP-BGP address family, 187
IS-IS PPP interface hello packet source
adjacency
OSPFv3 DR election configuration, 374
OSPFv3 IPsec profile configuration, 389
OSPFv3 NSSA area configuration, 372
OSPFv3 route redistribution, 377
OSPFv3 stub area configuration, 368
advertising
IP routing BGP COMMUNITY
NO_ADVERTISE path attribute, 178
IP routing BGP default route to peer/peer
IP routing BGP optimal route, 207
IP routing BGP optimal route advertisement, 207
IP routing BGP route advertisement rules, 182
IP routing BGP route generation, 203
IP routing RIP summary route advertisement, 46
IPv4 BGP fake AS number advertisement, 224
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
IPv6 BGP fake AS number advertisement, 224
OSPF host route advertisement, 79
OSPF route summarization configuration, 100
applying
area
IS-IS authentication (area), 148
OSPF area configuration (NSSA),
OSPF area configuration (stub),
OSPF authentication (area), 83
430
OSPFv3 NSSA area configuration, 372
OSPFv3 stub area configuration, 368
AS
IP routing BGP confederation, 244
IP routing BGP confederation compatibility,
IP routing BGP first AS number of EBGP route
IP routing BGP MED attribute, 217
IP routing BGP path AS_PATH attribute, 178
IP routing BGP path AS_SEQUENCE
IP routing BGP path AS_SET attribute, 178
IP routing IS-IS configuration, 153
IPv4 BGP 4-byte AS number suppression,
IPv4 BGP AS number substitution, 225
IPv4 BGP fake AS number advertisement,
IPv4 BGP local AS number appearance, 223
IPv4 BGP MED AS route comparison
(confederation peers), 220, 220
IPv4 BGP MED AS route comparison (diff
IPv4 BGP MED AS route comparison
IPv4 BGP MED default value, 217
IPv4 BGP private AS number removal, 226
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
IPv6 BGP 4-byte AS number suppression, 231
IPv6 BGP AS number substitution, 225
IPv6 BGP fake AS number advertisement, 224
IPv6 BGP local AS number appearance, 223
IPv6 BGP MED AS route comparison
(confederation peers), 220, 220
IPv6 BGP MED AS route comparison (diff ASs),
IPv6 BGP MED AS route comparison (per-AS),
IPv6 BGP MED default value, 217
IPv6 BGP private AS number removal, 226
IS-IS basic configuration, 132
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
AS_PATH
IPv4 BGP optimal route selection, 224
IPv6 BGP optimal route selection, 224
ASBR
OSPF discard route configuration, 75
OSPF route summarization (ASBR), 74
OSPFv3 redistributed route summarization
assigning
IPv6 IS-IS route convergence priority, 396
attribute
IP routing BGP AS_PATH attribute, 223
IP routing BGP MED attribute, 217
IP routing BGP path AS_PATH, 178
IP routing BGP path COMMUNITY, 178
IP routing BGP path LOCAL_PREF, 178
IP routing BGP path NEXT_HOP, 178
IP routing BGP path ORIGIN, 178
IP routing MP-BGP MP_REACH_NLRI extended
IP routing MP-BGP MP_UNREACH_NLRI
IPv4 BGP AS number substitution, 225
431
IPv4 BGP AS_PATH optimal route selection,
IPv4 BGP fake AS number advertisement,
IPv4 BGP local AS number appearance, 223
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff
IPv4 BGP MED AS route comparison
IPv4 BGP MED default value, 217
IPv4 BGP private AS number removal, 226
IPv6 BGP AS number substitution, 225
IPv6 BGP AS_PATH optimal route selection,
IPv6 BGP fake AS number advertisement,
IPv6 BGP local AS number appearance, 223
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff
IPv6 BGP MED AS route comparison
IPv6 BGP MED default value, 217
IPv6 BGP private AS number removal, 226
authenticating
IPv4 BGP peer MD5 authentication, 232
IPv6 BGP peer MD5 authentication, 232
IS-IS authentication (area), 148
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 148
IS-IS network security enhancement, 147
auto
RIPng IPsec profile application, 337
RIPv2 message authentication configuration,
IP routing IS-IS FRR automatic backup next
IPv4 BGP route summarization (automatic),
IS-IS automatic cost calculation, 135
automatic
RIPv2 automatic route summarization enable, 29
B backbone
backing up
bandwidth
BDR
BFD
IP routing RIP BFD (bidirectional detection/control
IP routing RIP BFD (single-hop echo detection),
IP routing RIP BFD (single-hop echo
detection/specific destination), 51
IPv6 static route BFD configuration, 320
IPv6 static route BFD control mode (direct next
IPv6 static route BFD control mode (indirect next
IPv6 static route BFD echo mode (single hop),
IPv6 static routing BFD (direct next hop), 324
IPv6 static routing BFD (indirect next hop), 327
OSPF detection configuration (bidirectional
OSPF detection configuration (single-hop echo),
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
432
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
(indirect next hop), 9 static routing BFD configuration, 9
static routing BFD single-hop echo mode, 10
6PE optional capabilities, 253
AS_PATH attribute configuration, 223
184, 244 confederation compatibility, 244
default route advertisement to peer/peer
dynamic peer configuration, 194
dynamic peer configuration (IPv4 unicast
dynamic peer configuration (IPv6 unicast
first AS number of EBGP route updates, 227
IP routing EBGP direct connections after link
IPv4 EBGP peer protection (low memory
IPv6 EBGP peer protection (low memory
large scale network management, 184
MED attribute configuration, 217
MP-BGP extended attributes, 186
optimal route advertisement, 207
route distribution control, 205
routing policy AS_PATH list, 413 routing policy COMMUNITY list, 413
session state change logging, 247
TCP connection source address, 202
troubleshooting, 310 troubleshooting peer connection state, 310
bidirectional forwarding detection.
IP routing RIP BFD (bidirectional detection/control
IPv6 static route BFD control mode (direct next
IPv6 static route BFD control mode (indirect next
IPv6 static route BFD echo mode (single hop),
OSPF BFD detection configuration (bidirectional
RIP BFD configuration (bidirectional control
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
Border Gateway Protocol.
broadcast
OSPF interface network type, 72
OSPFv3 network type (interface), 352
C
433
calculating
IS-IS SPF calculation interval, 144
OSPF FRR backup next hop calculation (LFA
OSPF SPF calculation interval, 81
OSPFv3 SPF calculation interval, 358
checking
OSPFv3 DD packet ignore MTU check, 359
classless inter-domain routing.
Use CIDR
CLNP
community
IPv4 BGP ORIGINATOR_ID attribute, 243
COMMUNITY
routing policy COMMUNITY list, 415
community
IP routing BGP COMMUNITY path attribute,
IPv6 BGP ORIGINATOR_ID attribute, 243
routing policy extended community list, 413,
comparing
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff
IPv4 BGP MED AS route comparison
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff
IPv6 BGP MED AS route comparison
confederating
IP routing BGP confederation compatibility,
IPv4 BGP MED AS route comparison
IPv6 BGP MED AS route comparison
configuring
BGP dynamic peer (IPv4 unicast address), 194
BGP dynamic peer (IPv6 unicast address), 194
IP routing BGP 6PE basics, 252
IP routing BGP 6PE optional capabilities, 253
IP routing BGP AS_PATH attribute, 223
IP routing BGP confederation, 244
IP routing BGP confederation compatibility, 244
IP routing BGP GR restarter, 245
IP routing BGP large-scale network, 241
IP routing BGP MED attribute, 217
IP routing BGP peer group, 195
IP routing BGP route filtering policies, 209
IP routing BGP route redistribution, 205
IP routing BGP route reflection, 242
IP routing BGP soft reset, 236
IP routing ECMP route max number, 5
IP routing FIB route max lifetime, 4
IP routing IS-IS circuit level, 133
IP routing IS-IS FRR automatic backup next hop
IP routing IS-IS IS level, 133
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
IP routing RIP BFD (bidirectional detection/control
IP routing RIP BFD (single-hop echo detection),
IP routing RIP BFD (single-hop echo
detection/specific destination), 51
IP routing RIP interface additional metric, 45
IP routing RIP route redistribution, 43
434
IP routing RIP summary route advertisement,
IPv4 BGP AS number substitution, 225
IPv4 BGP default local preference, 216
IPv4 BGP keepalive interval, 228
IPv4 BGP manual soft reset, 238
IPv4 BGP MED default value, 217
IPv4 BGP NEXT_HOP attribute, 221
IPv4 BGP route distribution filtering policies,
IPv4 BGP route preference, 215
IPv4 BGP route reception filtering policies, 211
IPv4 BGP route summarization, 264
IPv4 BGP route summarization (automatic ),
IPv4 BGP route summarization (manual), 206
IPv4 BGP route update interval, 229
IPv4 BGP-IGP route redistribution, 261
IPv6 BGP AS number substitution, 225
IPv6 BGP default local preference, 216
IPv6 BGP keepalive interval, 228
IPv6 BGP manual soft reset, 238
IPv6 BGP MED default value, 217
IPv6 BGP NEXT_HOP attribute, 221
435
IPv6 BGP route distribution filtering policies, 209
IPv6 BGP route preference, 215
IPv6 BGP route reception filtering policies, 211
IPv6 BGP route update interval, 229
IPv6 PBR interface (packet type-based), 410
IPv6 PBR local (packet type-based), 409
IPv6 PBR node match criteria, 407
IPv6 static route BFD control mode (direct next
IPv6 static route BFD control mode (indirect next
IPv6 static route BFD echo mode (single hop),
IPv6 static routing basics, 322
IPv6 static routing BFD (direct next hop), 324
IPv6 static routing BFD (indirect next hop), 327
IS-IS authentication (area), 148
IS-IS authentication (neighbor relationship), 147
IS-IS authentication (routing domain), 148
IS-IS interface DIS priority, 140
IS-IS interface P2P network type, 133
IS-IS LSP-calculated route filtering, 137
IS-IS redistributed route filtering, 138
IS-IS route convergence priority, 144
IS-IS route summarization, 136
IS-IS system ID > host name mapping, 145
IS-IS system ID > host name mapping
IS-IS system ID > host name mapping (static),
OSPF authentication (area), 83
OSPF authentication (interface), 83
OSPF BFD detection (bidirectional control),
OSPF BFD detection (single-hop echo), 93
OSPF DD packet interface MTU, 84
OSPF exit overflow interval, 85
OSPF FRR backup next hop (routing policy),
OSPF FRR backup next hop calculation (LFA
OSPF host route advertisement, 79
OSPF interface network type (broadcast), 72
OSPF interface network type (NBMA), 72
OSPF interface network type (P2MP), 73
OSPF interface network type (P2P), 73
OSPF LSDB external LSAs max number, 84
436
OSPF prefix prioritization, 88
OSPF prefix suppression (interface), 88
OSPF prefix suppression (OSPF process), 88
OSPF received route filtering, 75
OSPF redistributed route default parameters, 78
OSPF route redistribution (another routing
OSPF route redistribution (default route), 78
OSPF route summarization (ABR), 74
OSPF route summarization (ASBR), 74
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 interface DR priority, 359
OSPFv3 IPsec profile configuration, 389
OSPFv3 network management, 360
OSPFv3 network type (interface), 352
OSPFv3 prefix suppression, 362
OSPFv3 prefix suppression (interface), 363
OSPFv3 prefix suppression (OSPFv3 process),
OSPFv3 received route filtering, 354
OSPFv3 redistributed route summarization
OSPFv3 redistributed route tag, 357
OSPFv3 route redistribution, 377
OSPFv3 route redistribution (another routing
OSPFv3 route redistribution (default route),
OSPFv3 route summarization, 380
OSPFv3 route summarization (ABR), 353
PBR (interface/packet type-based), 317
PBR (local/packet type-based), 315
RIP additional routing metric, 28
RIP BFD (bidirectional control detection), 38
RIP BFD (single-hop echo
RIP BFD (single-hop echo detection/specific
RIP received/redistributed route filtering, 30
RIPng IPsec profile configuration, 344
RIPng packet zero field check, 336
RIPng received/redistributed route filtering, 334
RIPng route summarization, 333
RIPv2 message authentication, 34
413, 416, 420 routing policy (IPv4 route redistribution), 420
routing policy (IPv6 route redistribution), 423
routing policy apply clause, 418
routing policy AS_PATH list, 415 routing policy COMMUNITY list, 415
routing policy continue clause, 419
routing policy extended community list, 416
routing policy if-match clause, 416
routing policy IPv4 prefix list, 414
routing policy IPv6 prefix list, 415
static routing BFD (direct next hop), 15
static routing BFD (indirect next hop), 17
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
static routing BFD single-hop echo mode, 10
static routing default route, 23
static routing FRR (auto backup next hop), 12 static routing FRR BFD echo packet mode, 12
static routing FRRs(backup next hop), 11
connecting
IP routing BGP TCP connection source address,
IP routing EBGP direct connections after link
continue clause (routing policy),
controlling
IP routing BGP path selection, 214
IP routing BGP route distribution, 205
IP routing BGP route reception, 205
IP routing RIP BFD configuration (bidirectional
detection/control packet mode), 54
437
IPv6 static route BFD control mode (direct
IPv6 static route BFD control mode (indirect
IS-IS SPF calculation interval, 144
RIP additional routing metric configuration, 28
RIP interface advertisement, 27
RIP interface reception, 27, 27
RIP route control configuration, 28
convergence priority (IPv6 IS-IS), 396
convergence priority (IS-IS), 144
cost
IS-IS automatic cost calculation, 135
creating
CSNP
IS-IS CSNP packet send interval, 140
D dampening
IP routing BGP route dampening, 184
database
DD
OSPFv3 DD packet ignore MTU check, 359
default
IP routing BGP default route advertisement to
IPv4 BGP default local preference, 216
IPv4 BGP MED default value, 217
IPv6 BGP default local preference, 216
IPv6 BGP MED default value, 217
IPv6 default route configuration, 330
IS-IS default route advertisement, 136
OSPF redistributed route default parameters,
OSPFv3 route redistribution (default route), 356
RIP default route advertisement, 30
RIPng default route advertisement, 334
static routing configuration.
See under static routing delaying
OSPFv3 LSA transmission delay, 358
detecting
IP routing RIP BFD (bidirectional detection/control
IP routing RIP BFD (single-hop echo detection),
IP routing RIP BFD (single-hop echo
detection/specific destination), 51
OSPF BFD detection configuration (bidirectional
OSPF BFD detection configuration (single-hop
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
RIP BFD single-hop echo detection, 37
device
IP routing IS-IS configuration, 153
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
IS-IS route redistribution, 162
routing policy configuration, 420
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
DIS
438
IS-IS DIS election configuration, 158
IS-IS interface DIS priority, 140
disabling
IPv4 BGP AS_PATH optimal route selection,
IPv4 BGP session establishment disable, 234
IPv6 BGP AS_PATH optimal route selection,
IPv6 BGP session establishment disable, 234
IS-IS interface packet send/receive, 141
OSPF interface packet send/receive disable,
OSPFv3 interface packet send/receive, 360
displaying
distributing
IP routing BGP route distribution control, 205
IP routing extension attribute redistribution, 3
IP routing route redistribution, 3
IPv4 BGP-IGP route redistribution, 261
OSPF route redistribution configuration, 99
RIPng received/redistributed route filtering,
domain
IS-IS authentication (routing domain), 148
DR
OSPF DR election configuration, 108
OSPFv3 DR election configuration, 374
OSPFv3 interface DR priority, 359
DSCP
dynamic
IP routing dynamic routing protocols, 2
IS-IS system ID > host name mapping, 145
E
EBGP
direct connections after link failure, 231
IP routing BGP first AS number of route updates,
IPv4 BGP multiple hop EBGP session
IPv4 BGP private AS number removal from EBGP
IPv6 BGP multiple hop EBGP session
IPv6 BGP private AS number removal from EBGP
echo
IP routing RIP BFD (bidirectional detection/control
IP routing RIP BFD (single-hop echo detection),
IP routing RIP BFD (single-hop echo
detection/specific destination), 51
IPv6 static route BFD echo mode (single hop),
RIP BFD single-hop echo detection, 37
static routing BFD single-hop echo mode, 10
IP routing ECMP enhanced mode, 5
IP routing ECMP route max number, 5
electing
OSPF DR election configuration, 108
OSPFv3 DR election configuration, 374
enabling
IP routing BGP route flapping logging, 247
IP routing BGP session state change logging, 247
IP routing BGP SNMP notification, 246
439
IP routing EBGP direct connections after link
IP routing ECMP enhanced mode, 5
IP routing RIP (interface), 27
IPv4 BGP 4-byte AS number suppression,
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff
IPv4 BGP MED AS route comparison
IPv4 BGP multiple hop EBGP session
IPv4 BGP peer MD5 authentication, 232
IPv6 BGP 4-byte AS number suppression,
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff
IPv6 BGP MED AS route comparison
IPv6 BGP multiple hop EBGP session
IPv6 BGP peer MD5 authentication, 232
IS-IS automatic cost calculation, 135
IS-IS interface hello packet send, 141
IS-IS LSP fragment extension, 143
IS-IS neighbor state change logging, 146
IS-IS PPP interface hello packet source
OSPF neighbor state change logging, 85
OSPF RFC 1583 compatibility, 85
OSPFv3 neighbor state change logging, 360
RIP update source IP address check, 34
RIPv1 incoming message zero field check, 34
RIPv2 automatic route summarization, 29
support for IPv6 routes with prefixes longer than
enhancing
establishing
IPv4 BGP multiple hop EBGP session
IPv4 BGP session establishment disable, 234
IPv6 BGP multiple hop EBGP session
IPv6 BGP session establishment disable, 234
exit overflow interval (OSPF), 85
extending
IP routing MP-BGP MP_REACH_NLRI extended
IP routing MP-BGP MP_UNREACH_NLRI
IS-IS LSP fragment extension, 143
Exterior Gateway Protocol.
Use EGP external
OSPF LSDB external LSAs max number, 84
external BGP.
Use EGP
F fast reroute.
FIB
filtering
IP routing BGP route filtering policies, 209
IPv4 BGP route distribution filtering policies, 209
IPv4 BGP route reception filtering policies, 211
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
IPv6 BGP route distribution filtering policies, 209
IPv6 BGP route reception filtering policies, 211
440
IS-IS LSP-calculated routes, 137
IS-IS redistributed routes, 138
OSPF received route filtering, 75
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 received route filtering, 354
RIP received/redistributed route filtering, 30
RIPng received/redistributed route filtering,
routing policy apply clause, 418
routing policy COMMUNITY list,
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 419
routing policy extended community list, 413,
routing policy filter configuration, 414
routing policy if-match clause, 416
routing policy IP prefix list, 414
routing policy prefix list, 413
flooding
format
IS-IS NSAP address format, 125
forwarding
IPv6 PBR interface configuration, 408
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 407
IPv6 PBR local configuration (packet
IPv6 PBR policy configuration, 406
PBR configuration (interface), 315
PBR configuration (interface/packet type-based),
PBR configuration (local), 314
PBR configuration (local/packet type-based), 315
fragment
IS-IS LSP fragment extension, 143
FRR
IP routing BGP FRR configuration, 249
IP routing IS-IS FRR automatic backup next hop
OSPF backup next hop (routing policy), 94
OSPF backup next hop calculation (LFA
static routing FRR configuration,
G
garbage-collect timer (RIP), 32
Generalized TTL Security Mechanism.
generating
OSPFv3 LSA generation interval, 359
Graceful Restart (GR)
IP routing BGP configuration, 245
IPv4 BGP GR configuration, 282
OSPF GR helper configuration, 91
OSPF GR restarter configuration, 90
OSPFv3 GR helper configuration, 364
441
OSPFv3 GR restarter configuration, 363
RIP GR helper configuration, 36
RIP GR restarter configuration, 36
group
IP routing BGP peer group, 195
GTSM
IP routing BGP configuration, 235
H hello
IS-IS hello packet send interval, 139
IS-IS interface hello packet send, 141
IS-IS PPP interface hello packet source
HO-DSP (IS-IS area address), 126
holdtime
hop
OSPF BFD detection configuration
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
host
IS-IS system ID > host name mapping, 145
I
IBGP
IP routing BGP confederation, 244
IPv4 BGP ORIGINATOR_ID attribute, 243
IPv6 BGP ORIGINATOR_ID attribute, 243
ICMP
OSPF area configuration (NSSA), 106
OSPF area configuration (stub), 103
OSPF DR election configuration, 108
OSPF route redistribution configuration, 99
OSPF route summarization configuration, 100
OSPF virtual link configuration, 112
OSPFv3 route summarization, 380
ID
IETF
ignoring
IP routing BGP first AS number of EBGP route
IPv4 BGP ORIGINATOR_ID attribute, 243
IPv6 BGP ORIGINATOR_ID attribute, 243
IGP
OSPFv3 DD packet MTU check, 359
IP routing BGP ORIGIN path attribute, 178
IP routing IS-IS configuration, 153
IP routing RIP configuration, 40
IPv4 BGP-IGP route redistribution, 261
IS-IS basic configuration, 132
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
RIP neighbor specification, 35
INCOMPLETE
IP routing BGP ORIGIN path attribute, 178
Incremental Shortest Path First.
injecting
inter-area
interface
IPv6 PBR interface configuration, 408
IPv6 PBR interface configuration (packet
PBR configuration (interface), 315
442
PBR configuration (interface/packet
Intermediate System-to-Intermediate System.
Use
internal
IP routing BGP.
INTERNET
IP routing BGP COMMUNITY path attribute,
interval
IP routing BGP soft reset, 236
IPv4 BGP keepalive interval, 228
IPv4 BGP route update interval, 229
IPv6 BGP keepalive interval, 228
IPv6 BGP route update interval, 229
IS-IS CSNP packet send interval, 140
IS-IS hello packet send interval, 139
IS-IS SPF calculation interval, 144
OSPF exit overflow interval, 85
OSPF LSA generation interval, 81
OSPF SPF calculation interval, 81
OSPFv3 LSA generation interval, 359
OSPFv3 SPF calculation interval, 358
intra-area
IP addressing
IP routing RIP configuration, 40
RIP update source IP address check, 34
IP routing
BGP 6PE optional capabilities, 253
BGP confederation compatibility, 244
BGP default route advertisement to peer/peer
BGP dynamic peer (IPv4 unicast address),
BGP dynamic peer (IPv6 unicast address),
BGP first AS number of EBGP route updates,
443
BGP large scale network management, 184
BGP optimal route advertisement, 207
BGP protocols and standards, 188
BGP route filtering policies, 209
BGP route flapping logging, 247
BGP session state change logging, 247
BGP SNMP notification enable, 246
BGP TCP connection source address, 202
displaying IPv6 static routing, 322
ECMP route max number configuration, 5
extension attribute redistribution, 3
IPv4.
IPv6.
IPv6 default route.
See under IPv6 static routing
IPv6 policy-based routing.
IPv6 static routing.
IS-IS authentication (area), 148
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 148
IS-IS automatic cost calculation, 135
IS-IS basic configuration, 132
IS-IS basics configuration, 153
IS-IS CSNP packet send interval, 140
IS-IS default route advertisement, 136
IS-IS DIS election configuration, 158
IS-IS hello packet send interval, 139
IS-IS interface DIS priority, 140
IS-IS interface hello packet send, 141
IS-IS interface packet send/receive, 141
IS-IS LSP fragment extension, 143
IS-IS LSP-calculated route filtering, 137
IS-IS network optimization, 139
IS-IS network security enhancement, 147
IS-IS protocols and standards, 131
444
IS-IS redistributed route filtering, 138
IS-IS route convergence priority, 144
IS-IS route summarization, 136
IS-IS SPF calculation interval, 144
IS-IS system ID > host name mapping, 145
MP-BGP protocols and standards, 188
OSPF area configuration (NSSA),
OSPF area configuration (stub),
OSPF BFD detection configuration (bidirectional
OSPF BFD detection configuration (single-hop
OSPF DD packet interface MTU, 84
OSPF discard route configuration, 75
OSPF DR election configuration, 108
OSPF exit overflow interval, 85
OSPF host route advertisement, 79
OSPF interface network type (broadcast), 72
OSPF interface network type (NBMA), 72
OSPF interface network type (P2MP), 73
OSPF interface network type (P2P), 73
OSPF interface packet send/receive disable, 82
OSPF LSA generation interval, 81
OSPF LSA transmission delay, 80
OSPF LSDB external LSAs max number, 84
OSPF neighbor state change, 85
OSPF network management traps, 86
OSPF prefix prioritization, 88
OSPF protocols and standards, 66
OSPF received route filtering, 75
OSPF RFC 1583 compatibility, 85
OSPF route redistribution configuration, 99
OSPF route summarization configuration, 100
OSPF SPF calculation interval, 81
OSPF virtual link configuration, 112
OSPFv3 DD packet ignore MTU check, 359
OSPFv3 DR election configuration, 374
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 interface DR priority, 359
OSPFv3 interface packet send/receive
OSPFv3 IPsec profile application, 365
445
OSPFv3 IPsec profile configuration, 389
OSPFv3 LSA generation interval, 359
OSPFv3 LSA transmission delay, 358
OSPFv3 neighbor state change logging, 360
OSPFv3 network management traps, 360
OSPFv3 network optimization, 357
OSPFv3 network type (interface), 352
OSPFv3 NSSA area configuration, 372
OSPFv3 prefix suppression, 362
OSPFv3 protocols and standards, 348
OSPFv3 received route filtering, 354
OSPFv3 redistributed route summarization
OSPFv3 route summarization (ABR), 353
OSPFv3 SPF calculation interval, 358
OSPFv3 stub area configuration, 368
PBR configuration (interface), 315
PBR configuration (local), 314
policy AS_PATH list, 415 policy COMMUNITY list, 415
policy configuration (IPv4 route redistribution),
policy configuration (IPv6 route redistribution),
policy extended community list, 416
policy filter configuration, 414
policy filtering, 413 policy filters, 413
policy-based routing.
RIP additional routing metric configuration, 28
RIP BFD (bidirectional detection/control
RIP BFD (single-hop echo detection), 49
RIP BFD (single-hop echo detection/specific
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
RIP default route advertisement, 30
RIP host route reception disable, 29
RIP interface additional metric, 45
RIP interface advertisement control, 27
RIP interface reception control, 27
RIP neighbor specification, 35
RIP network management configuration, 35
RIP packet send rate configuration, 35
RIP poison reverse configuration, 32
RIP preference configuration, 31
RIP received/redistributed route filtering, 30
RIP route control configuration, 28
RIP route redistribution configuration, 31
446
RIP routing loop prevention, 24
RIP split horizon configuration, 32
RIP summary route advertisement, 46
RIP update source IP address check, 34
RIPng default route advertisement, 334
RIPng IPsec profile application, 337
RIPng IPsec profile configuration, 344
RIPng network optimization, 335
RIPng packet zero field check configuration, 336
RIPng poison reverse configuration, 335
RIPng protocols and standards, 332
RIPng received/redistributed route filtering, 334
RIPng route summarization, 333
RIPng routing metric configuration, 333
RIPng split horizon configuration, 335
RIPng timer configuration, 335
RIPv1 message zero field check, 34
RIPv2 message authentication configuration, 34
RIPv2 route summarization configuration, 29
route recursion, 3 route redistribution, 3
static route, 13 static routing basic configuration, 13
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
(indirect next hop), 9 static routing BFD configuration, 9
static routing BFD configuration (direct next hop),
static routing BFD configuration (indirect next
static routing BFD single-hop echo mode, 10
static routing configuration, 8, 8
static routing default route configuration, 23
static routing FRR configuration,
support for IPv6 routes with prefixes longer
troubleshooting BGP peer connection state,
troubleshooting OSPF configuration, 123
troubleshooting OSPF incorrect routing
troubleshooting OSPF no neighbor
IPsec
OSPFv3 IPsec profile application, 365
OSPFv3 IPsec profile configuration, 389
RIPng IPsec profile application, 337
IPv4
RIPng IPsec profile configuration, 344
IP routing FIB route max lifetime, 4
IP routing IS-IS configuration, 153
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
IPv6 BGP 6PE configuration, 296
IS-IS basic configuration, 132
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
OSPF area configuration (NSSA), 106
OSPF area configuration (stub), 103
OSPF DR election configuration, 108
OSPF route redistribution configuration, 99
OSPF route summarization configuration, 100
OSPF virtual link configuration, 112
routing policy ACLs, 413 routing policy configuration,
routing policy configuration (IPv4 route
routing policy IP prefix list, 414
routing policy prefix list, 413
IPv4 BGP
4-byte AS number suppression, 231
6PE optional capabilities, 253
AS_PATH optimal route selection, 224
confederation configuration, 275
default route advertisement to peer/peer group,
fake AS number advertisement, 224
IP routing BGP-IGP route redistribution, 261
load balancing configuration, 267
local AS number appearance, 223
manual soft reset configuration, 238
MED AS route comparison (confederation peers),
MED AS route comparison (diff ASs), 218
MED AS route comparison (per-AS), 219
multiple hop EBGP session establishment, 230
path selection configuration, 279
private AS number removal, 226
received route preferred value, 214 route dampening, 214
route distribution filtering policies, 209
route preference configuration, 215
route reception filtering policies, 211
route reflector configuration, 273
route summarization (automatic), 205
route summarization (manual), 206
routes received from peer/peer group, 208
session establishment disable, 234
IPv4 EBGP
447
peer protection (low memory exemption), 240
IPv4 IBGP
IPv6
IP routing FIB route max lifetime, 4
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
IS-IS.
OSPFv3 DD packet ignore MTU check, 359
OSPFv3 DR election configuration, 374
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 interface DR priority, 359
OSPFv3 interface packet send/receive
OSPFv3 IPsec profile application, 365
OSPFv3 IPsec profile configuration, 389
OSPFv3 LSA generation interval, 359
OSPFv3 LSA transmission delay, 358
OSPFv3 neighbor state change logging, 360
OSPFv3 network optimization, 357
OSPFv3 network type (interface), 352
OSPFv3 NSSA area configuration, 372
OSPFv3 received route filtering, 354
OSPFv3 SPF calculation interval, 358
OSPFv3 stub area configuration, 368
policy-based routing.
routing policy ACLs, 413 routing policy configuration,
routing policy configuration (IPv6 route
routing policy IP prefix list, 414
routing policy prefix list, 413
IPv6 BGP
4-byte AS number suppression, 231
AS_PATH optimal route selection, 224
default route advertisement to peer/peer group,
fake AS number advertisement, 224
local AS number appearance, 223
MED AS route comparison (confederation peers),
MED AS route comparison (diff ASs), 218
MED AS route comparison (per-AS), 219
multiple hop EBGP session establishment, 230
private AS number removal, 226
received route preferred value, 214 route dampening, 214
route distribution filtering policies, 209
route reception filtering policies, 211
route reflector configuration, 293
routes received from peer/peer group, 208
448
session establishment disable, 234
IPv6 EBGP
peer protection (low memory exemption), 240
IPv6 IBGP
IPv6 IS-IS
network optimization, 396 network tuning, 396
route control configuration, 394
route convergence priority assignment, 396
IPv6 PBR
apply clause, 405 configuration,
interface configuration (packet type-based),
local configuration (packet type-based), 409
match mode/node clause relationship, 406
IPv6 provider edge.
IPv6 static routing
BFD configuration (direct next hop), 324
BFD configuration (indirect next hop), 327
BFD control mode (direct next hop), 321
BFD control mode (indirect next hop), 321
BFD echo mode (single hop), 321
default route configuration, 330
IS-IS
449
authentication (neighbor relationship), 147
authentication (routing domain), 148
authentication configuration, 165
circuit level configuration, 133
CSNP packet send interval, 140
default route advertisement, 136
DIS election configuration, 158
enabling automatic cost calculation, 135
FRR automatic backup next hop calculation, 151
global cost configuration, 135
hello multiplier, 139 hello packet send interval, 139
interface cost configuration, 134
interface hello packet send enable, 141
interface P2P network type configuration, 133
interface packet send/receive disable, 141
IPv6 IS-IS.
LSP parameter configuration, 141
LSP-calculated route filtering, 137
neighbor state change logging, 146
network security enhancement, 147
nonstop routing (NSR) configuration,
point-to-point network type, 128
PPP interface hello packet source address
redistributed route filtering, 138
route control configuration, 134
route convergence priority, 144
route leaking configuration, 138
system ID > host name mapping, 145
ISPF
K keepalive
IPv4 BGP keepalive interval, 228
IPv4 BGP route update interval, 229
IPv6 BGP keepalive interval, 228
IPv6 BGP route update interval, 229
L label
IP routing RIB label max lifetime, 4
leaking level
IPv4 EBGP peer protection (level 2 threshold
IPv6 EBGP peer protection (level 2 threshold
limiting
IPv4 BGP routes received from peer/peer
IPv6 BGP routes received from peer/peer group,
link
IP routing EBGP direct connection after link
IS-IS automatic cost calculation, 135
OSPF virtual link configuration, 112
list
routing policy COMMUNITY list,
routing policy extended community list,
routing policy IP prefix list, 414
routing policy prefix list, 413
IP routing ECMP enhanced mode, 5
IP routing ECMP route max number, 5
load sharing
local
IP routing BGP LOCAL_PREF path attribute, 178
IPv4 BGP default local preference, 216
IPv6 BGP default local preference, 216
IPv6 PBR local configuration, 407
IPv6 PBR local configuration (packet type-based),
PBR configuration (local), 314
PBR configuration (local/packet type-based), 315
logging
IP routing BGP route flapping logging, 247
IP routing BGP session state change logging, 247
450
IS-IS neighbor state change, 146
OSPF neighbor state change, 85
OSPFv3 neighbor state change logging, 360
loop
LSA
RIP routing loop prevention, 24
OSPF exit overflow interval, 85
OSPF LSA generation interval, 81
OSPF LSA retransmission packet timer, 79
OSPF LSA transmission delay, 80
OSPF LSDB external LSAs max number, 84
OSPFv3 inter-area-prefix LSA, 347
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 inter-area-router LSA, 347
OSPFv3 intra-area-prefix LSA, 347
OSPFv3 LSA generation interval, 359
OSPFv3 LSA transmission delay, 358
LSAck
LSDB
LSP
OSPF LSDB external LSAs max number, 84
IS-IS LSP fragment extension, 143
LSR
IS-IS route summarization, 136
LSU
M maintaining
managing
IP routing BGP large scale network management,
manual
IPv4 BGP route summarization (manual), 206
mapping
IS-IS system ID > host name mapping, 145
IS-IS system ID > host name mapping (dynamic),
IS-IS system ID > host name mapping (static),
matching
IPv6 PBR node match criteria, 407
routing policy if-match clause,
MD5
IPv4 BGP peer MD5 authentication, 232
IPv6 BGP peer MD5 authentication, 232
MED
IP routing BGP MED attribute, 217
IP routing BGP path attribute, 178
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff ASs),
451
IPv4 BGP MED AS route comparison
IPv4 BGP MED default value, 217
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff
IPv6 BGP MED AS route comparison
IPv6 BGP MED default value, 217
memory
IPv4 EBGP peer protection (low memory
IPv6 EBGP peer protection (low memory
message
IP routing BGP notification, 178
IP routing BGP route-refresh, 178
RIPv1 message zero field check enable, 34
RIPv2 message authentication configuration,
metric
IP routing RIP interface additional metric, 45
RIP additional routing metric configuration, 28
RIPng routing metric configuration, 333
mode
IPv6 static route BFD control (direct next hop),
IPv6 static route BFD control (indirect next
IPv6 static route BFD echo (single hop), 321
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
static routing BFD single-hop echo mode, 10
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
MPLS
IP routing BGP 6PE basics, 252
IP routing BGP 6PE optional capabilities, 253
routing policy extended community list, 413
MPU
MTU
OSPF DD packet interface MTU, 84
OSPFv3 DD packet ignore MTU check, 359
multicast
RIPng basic configuration, 332
Multiprotocol Extensions for BGP-4.
N naming
IS-IS system ID > host name mapping, 145
NBMA
OSPF interface network type, 72
OSPFv3 network type (interface), 352
ND
OSPFv3 DR election configuration, 374
OSPFv3 IPsec profile configuration, 389
452
OSPFv3 neighbor state change logging, 360
OSPFv3 NSSA area configuration, 372
OSPFv3 route redistribution, 377
OSPFv3 stub area configuration, 368
neighbor
IS-IS authentication (neighbor relationship),
IS-IS neighbor state change logging, 146
OSPF neighbor state change logging, 85
RIP neighbor specification, 35
network
entity title.
Use NET
IP routing BGP 6PE basics, 252
IP routing BGP 6PE optional capabilities, 253
IP routing BGP AS_PATH attribute, 223
IP routing BGP default route advertisement to
IP routing BGP GR restarter, 245
IP routing BGP GTSM configuration, 235
IP routing BGP large-scale network, 241
IP routing BGP load balancing, 182
IP routing BGP MED attribute, 217
IP routing BGP optimal route advertisement,
IP routing BGP optimization, 228
IP routing BGP path selection, 214
IP routing BGP route dampening, 184
IP routing BGP route distribution, 205
IP routing BGP route filtering policies, 209
IP routing BGP route flapping logging, 247
IP routing BGP route generation, 203
IP routing BGP route reception, 205
IP routing BGP route recursion, 182
IP routing BGP route reflection, 242
IP routing BGP route reflector, 184
453
IP routing BGP route selection, 182, 182
IP routing BGP route summarization,
IP routing BGP session state change logging, 247
IP routing BGP SNMP notification enable, 246
IP routing BGP soft reset, 236
IP routing BGP TCP connection source address,
IP routing dynamic routing protocols, 2
IP routing ECMP enhanced mode, 5
IP routing ECMP route max number, 5
IP routing extension attribute redistribution, 3
IP routing FIB route max lifetime, 4
IP routing IS-IS circuit level, 133
IP routing IS-IS IS level, 133
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
IP routing RIP BFD (bidirectional detection/control
IP routing RIP BFD (single-hop echo detection),
IP routing RIP BFD (single-hop echo
detection/specific destination), 51
IP routing RIP interface additional metric, 45
IP routing RIP route redistribution, 43
IP routing RIP summary route advertisement, 46
IP routing route preference, 2
IP routing route redistribution, 3
IP routing support for IPv6 routes with prefixes
IPv4 BGP 4-byte AS number suppression, 231
IPv4 BGP AS number substitution, 225
IPv4 BGP AS_PATH optimal route selection, 224
IPv4 BGP BFD configuration, 248
IPv4 BGP default local preference, 216
IPv4 BGP fake AS number advertisement, 224
IPv4 BGP IGP route redistribution, 204
IPv4 BGP keepalive interval, 228
IPv4 BGP local network injection, 203
IPv4 BGP multiple hop EBGP session
IPv4 BGP NEXT_HOP attribute, 221
IPv4 BGP peer MD5 authentication, 232
IPv4 BGP private AS number removal, 226
IPv4 BGP received route preferred value, 214
IPv4 BGP route preference, 215
IPv4 BGP route update interval, 229
IPv4 BGP routes received from peer/peer
IPv4 BGP session establishment disable, 234
IPv6 BGP 4-byte AS number suppression,
IPv6 BGP AS number substitution, 225
IPv6 BGP AS_PATH optimal route selection,
IPv6 BGP default local preference, 216
IPv6 BGP fake AS number advertisement,
IPv6 BGP IGP route redistribution, 204
IPv6 BGP keepalive interval, 228
IPv6 BGP local network injection, 203
IPv6 BGP multiple hop EBGP session
IPv6 BGP NEXT_HOP attribute, 221
IPv6 BGP peer MD5 authentication, 232
IPv6 BGP private AS number removal, 226
IPv6 BGP received route preferred value, 214
IPv6 BGP route preference, 215
IPv6 BGP route update interval, 229
IPv6 BGP routes received from peer/peer
IPv6 BGP session establishment disable, 234
IPv6 IS-IS basic configuration, 394
IPv6 IS-IS BFD configuration, 396
IPv6 IS-IS network optimization, 396
IPv6 IS-IS network tuning, 396
IPv6 IS-IS route convergence priority, 396
IPv6 PBR interface configuration, 408
IPv6 PBR local configuration, 407
IPv6 PBR node match criteria, 407
IPv6 PBR policy configuration, 406
IPv6 PBR-Track collaboration, 406
IPv6 static route BFD configuration, 320
454
IPv6 static route BFD control mode (direct next
IPv6 static route BFD control mode (indirect next
IPv6 static route BFD echo mode (single hop),
IPv6 static route configuration, 320
IS-IS authentication (area), 148
IS-IS authentication (neighbor relationship), 147
IS-IS authentication (routing domain), 148
IS-IS automatic cost calculation, 135
IS-IS basic configuration, 132
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
IS-IS hello packet send interval, 139
IS-IS interface DIS priority, 140
IS-IS interface hello packet send, 141
IS-IS interface P2P network type, 133
IS-IS interface packet send/receive, 141
IS-IS LSP fragment extension, 143
IS-IS neighbor state change logging, 146
IS-IS network optimization, 139
IS-IS point-to-point type, 128
IS-IS route convergence priority, 144
IS-IS route redistribution, 162
IS-IS security enhancement, 147
IS-IS SPF calculation interval, 144
IS-IS system ID > host name mapping, 145
OSPF area configuration (NSSA),
OSPF area configuration (stub),
OSPF BFD detection configuration
OSPF BFD detection configuration
OSPF DD packet interface MTU, 84
OSPF discard route configuration, 75
OSPF exit overflow interval, 85
OSPF host route advertisement, 79
OSPF interface network type (broadcast), 72
OSPF interface network type (NBMA), 72
OSPF interface network type (P2MP), 73
OSPF interface network type (P2P), 73
OSPF interface packet send/receive disable,
OSPF LSA generation interval, 81
OSPF LSA transmission delay, 80
OSPF LSDB external LSAs max number, 84
OSPF neighbor state change logging, 85
OSPF prefix prioritization, 88
OSPF received route filtering, 75
455
OSPF RFC 1583 compatibility, 85
OSPF SPF calculation interval, 81
OSPFv3 DD packet ignore MTU check, 359
OSPFv3 Inter-Area-Prefix LSA filtering, 354
OSPFv3 interface DR priority, 359
OSPFv3 interface packet send/receive disable,
OSPFv3 IPsec profile application, 365
OSPFv3 LSA generation interval, 359
OSPFv3 LSA transmission delay, 358
OSPFv3 neighbor state change logging, 360
OSPFv3 network management, 360
OSPFv3 network type (interface), 352
OSPFv3 prefix suppression, 362
OSPFv3 received route filtering, 354
OSPFv3 redistributed route summarization
OSPFv3 route redistribution, 356
OSPFv3 route summarization, 353
OSPFv3 route summarization (ABR), 353
OSPFv3 SPF calculation interval, 358
RIP additional routing metric configuration, 28
RIP default route advertisement, 30
RIP host route reception disable, 29
RIP interface advertisement control, 27
RIP interface reception control, 27
RIP network management configuration, 35
RIP packet send rate configuration, 35
RIP poison reverse configuration, 32
RIP preference configuration, 31
RIP received/redistributed route filtering, 30
RIP route control configuration, 28
RIP route redistribution configuration, 31
RIP routing loop prevention, 24
RIP split horizon configuration, 32
RIP update source IP address check, 34
RIPng basic configuration, 332
RIPng default route advertisement, 334
RIPng IPsec profile application, 337
RIPng network optimization, 335
RIPng packet zero field check, 336
RIPng received/redistributed route filtering,
RIPng route redistribution, 335
RIPng route summarization, 333
RIPng routing metric configuration, 333
RIPng timer configuration, 335
RIPv1 message zero field check, 34
RIPv2 message authentication configuration, 34
RIPv2 route summarization configuration, 29
routing policy apply clause, 418
routing policy AS_PATH list, 415 routing policy COMMUNITY list, 415
routing policy configuration, 416
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 419
routing policy creation, 416 routing policy extended community list, 416
routing policy filter configuration, 414
routing policy if-match clause, 416
routing policy IP prefix list, 414
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
(indirect next hop), 9 static routing BFD configuration, 9
static routing BFD single-hop echo mode, 10
static routing configuration, 8
static routing FRR configuration, 11
network management
IP routing BGP large scale networks, 184
IP routing IS-IS configuration, 153
IP routing RIP configuration, 40
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
456
IPv6 default route configuration, 330
IPv6 IS-IS basic configuration, 397
IPv6 IS-IS BFD configuration, 401
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration (packet
IPv6 static routing basic configuration, 322
IPv6 static routing BFD (direct next hop), 324
IPv6 static routing BFD (indirect next hop),
IPv6 static routing configuration,
OSPF DR election configuration, 108
OSPF route redistribution configuration, 99
OSPF route summarization configuration, 100
OSPF virtual link configuration, 112
OSPFv3 DR election configuration, 374
OSPFv3 IPsec profile configuration, 389
OSPFv3 network optimization, 357
OSPFv3 NSSA area configuration, 372
OSPFv3 route redistribution, 377
OSPFv3 route summarization, 380
OSPFv3 stub area configuration, 368
PBR configuration (interface/packet
PBR configuration (local/packet type-based),
RIPng basic configuration, 339
RIPng IPsec profile configuration, 344
RIPng route redistribution, 341
static routing basic configuration, 13
static routing BFD configuration (direct next hop),
static routing BFD configuration (indirect next
static routing configuration, 8
static routing default route configuration, 23
static routing FRR configuration, 20
NEXT_HOP
IP routing BGP path attribute, 178
IPV4 BGP NEXT_HOP attribute configuration,
IPV6 BGP NEXT_HOP attribute configuration,
NO_ADVERTISE
IP routing BGP COMMUNITY path attribute, 178
NO_EXPORT
IP routing BGP COMMUNITY path attribute, 178
NO_EXPORT_SUBCONFED
IP routing BGP COMMUNITY path attribute, 178
node
IPv6 PBR node match criteria, 407
IPv6 PBR-Track collaboration, 406
routing policy continue clause,
routing policy deny match, 413 routing policy if-match clause,
routing policy permit match, 413
non-IETF
notifying
IP routing BGP notification message, 178
IP routing BGP SNMP notification enable, 246
NSAP
457
NSR
NSSA
number
IP routing BGP first AS number of EBGP route
IPv4 BGP 4-byte AS number suppression,
IPv4 BGP AS number substitution, 225
IPv4 BGP fake AS number advertisement,
IPv4 BGP local AS number appearance, 223
IPv4 BGP private AS number removal, 226
IPv6 BGP 4-byte AS number suppression,
IPv6 BGP AS number substitution, 225
IPv6 BGP fake AS number advertisement,
IPv6 BGP local AS number appearance, 223
IPv6 BGP private AS number removal, 226
O open
Open Shortest Path First.
Open Shortest Path First version 3.
optimal
IP routing FIB table optimal routes, 1
optimizing
ORIGIN
IP routing BGP path attribute, 178
authentication configuration, 83
BFD detection configuration (bidirectional
BFD detection configuration (single-hop echo), 93
DD packet interface MTU add, 84
discard route configuration, 75
DR election configuration, 108
FRR backup next hop calculation (LFA algorithm),
FRR backup next hop specification (routing
interface network type (broadcast), 72 interface network type (NBMA), 72
interface network type (P2MP), 73 interface network type (P2P), 73
interface packet send/receive disable, 82
458
LSDB external LSAs max number, 84
LSU transmit rate configuration, 87
neighbor state change logging, 85
network management configuration, 86
network optimization, 79 network tuning, 79
network type configuration, 71
nonstop routing (NSR) configuration,
packet DSCP value configuration, 84
prefix suppression (interface), 88 prefix suppression (OSPF process), 88
route control configuration, 74
route redistribution configuration, 99
route summarization configuration, 100
troubleshoot configuration, 123
troubleshoot incorrect routing information, 124
troubleshoot no neighbor relationship
area parameter configuration, 350
DD packet ignore MTU check, 359
P
459
DR election configuration, 374
GR restarter configuration, 363
Inter-Area-Prefix LSA filtering, 354 interface cost configuration, 354
interface packet send/receive disable, 360
IPsec profile application, 365
IPsec profile configuration, 389
NBMA neighbor configuration, 352
neighbor state change logging, 360 network management configuration, 360
network optimization, 357 network tuning, 357
network type configuration, 351
network type configuration (interface), 352
nonstop routing (NSR) configuration,
P2MP neighbor configuration, 352
prefix suppression (interface), 363 prefix suppression (OSPFv3 process), 363
redistributed route summarization (ASBR), 353
route control configuration, 353
route redistribution (another routing protocol), 356 route redistribution (default route), 356
route summarization (ABR), 353
stub router configuration, 362
virtual link configuration, 351
P2MP
OSPF interface network type, 73
P2P
OSPF interface network type, 73
OSPFv3 network type (interface), 352
packet
IP routing dynamic routing protocols, 2
IP routing extension attribute redistribution, 3
IP routing route preference, 2
IP routing route redistribution, 3
IPv6 PBR interface configuration, 408
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 407
IPv6 PBR local configuration (packet
IPv6 PBR policy configuration, 406
IS-IS CSNP packet send interval, 140
IS-IS hello packet send interval, 139
IS-IS interface hello packet send, 141
IS-IS interface packet send/receive, 141
IS-IS PPP interface hello packet source
OSPF DD packet interface MTU, 84
OSPF exit overflow interval, 85
OSPF interface packet send/receive disable, 82
OSPF LSDB external LSAs max number, 84
OSPF RFC 1583 compatibility, 85
OSPF route redistribution configuration, 99
OSPFv3 DD packet ignore MTU check, 359
OSPFv3 DR election configuration, 374
OSPFv3 interface packet send/receive disable,
OSPFv3 IPsec profile configuration, 389
OSPFv3 NSSA area configuration, 372
OSPFv3 route redistribution, 377
OSPFv3 stub area configuration, 368
PBR configuration (interface), 315
PBR configuration (interface/packet type-based),
PBR configuration (local), 314
PBR configuration (local/packet type-based), 315
RIP BFD configuration (bidirectional control
RIP BFD configuration (single-hop echo
RIP BFD configuration (single-hop echo
detection/specific destination), 37
RIP network management configuration, 35
RIP packet send rate configuration, 35
RIPng packet zero field check, 336
parameter
460
IS-IS route convergence priority, 144
IS-IS SPF calculation interval, 144
OSPF redistributed route default parameters,
path
IP routing BGP MED attribute, 217
IP routing BGP path attributes, 178
IP routing BGP path selection, 214
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff
IPv4 BGP MED AS route comparison
IPv4 BGP MED default value, 217
IPv4 BGP NEXT_HOP attribute, 221
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff
IPv6 BGP MED AS route comparison
IPv6 BGP MED default value, 217
IPv6 BGP NEXT_HOP attribute, 221
PBR
312, 313, 314, 315 configuration (interface), 315
configuration (interface/packet type-based),
configuration (local/packet type-based), 315 displaying, 315
interface PBR, 312 local PBR, 312
node action configuration, 314
relationship between match mode/clauses,
PDU
PE
IP routing BGP 6PE basics, 252
IP routing BGP 6PE optional capabilities, 253
peer
IPv6 BGP 6PE configuration, 296
IP routing BGP default route advertisement to
IPv4 BGP MED AS route comparison
IPv4 BGP peer MD5 authentication, 232
IPv4 BGP session establishment disable, 234
IPv4 EBGP peer protection (low memory
IPv6 BGP MED AS route comparison
IPv6 BGP peer MD5 authentication, 232
IPv6 BGP session establishment disable, 234
IPv6 EBGP peer protection (low memory
IS-IS neighbor state change logging, 146
permitting
IPv4 BGP local AS number appearance, 223
IPv6 BGP local AS number appearance, 223
PIC
point-to-point IS-IS network type, 128
policy
IP routing BGP route filtering policy, 209
IPv4 BGP route distribution filtering policy, 209
IPv4 BGP route reception filtering policy, 211
IPv6 BGP route distribution filtering policy, 209
IPv6 BGP route reception filtering policy, 211
461
IPv6 PBR interface configuration, 408
IPv6 PBR interface configuration (packet
IPv6 PBR local configuration, 407
IPv6 PBR local configuration (packet
IPv6 PBR match mode/node clause
IPv6 PBR policy configuration, 406
OSPF FRR backup next hop (routing policy),
PBR configuration (interface), 315
PBR configuration (interface/packet
PBR configuration (local), 314
PBR configuration (local/packet type-based),
routing policy apply clause, 418
routing policy AS_PATH list, 415 routing policy COMMUNITY list, 415
routing policy configuration (IPv4 route
routing policy configuration (IPv6 route
routing policy continue clause, 419
routing policy creation, 416 routing policy extended community list, 416
routing policy filter configuration, 414
routing policy if-match clause, 416
routing policy IP prefix list, 414
policy-based routing.
PPP interface hello packet source address check,
preference
IP routing route preference, 2
OSPF host route advertisement, 79
preferred value
IP routing BGP received route, 214
preferring
IS-IS preference specification, 135
prefix
OSPF prefix prioritization, 88
OSPFv3 prefix suppression, 362
routing policy IP prefix list, 414
routing policy prefix list, 413
prioritizing
OSPF prefix prioritization, 88
priority
IPv6 IS-IS route convergence priority, 396
IS-IS interface DIS priority, 140
IS-IS route convergence priority, 144
OSPFv3 interface DR priority, 359
procedure advertising IP routing BGP default route to
peer/peer group, 207 advertising IP routing BGP optimal route, 207
advertising IPv4 BGP fake AS number, 224 advertising IPv6 BGP fake AS number, 224
advertising IS-IS default route, 136
advertising RIP default route, 30
advertising RIPng default route, 334
advertising RIPv2 summary route, 29
applying OSPFv3 IPsec profile, 365
applying RIPng IPsec profile, 337
assigning IPv6 IS-IS route convergence priority,
configuring BGP dynamic peer, 194
configuring BGP dynamic peer (IPv4 unicast
configuring BGP dynamic peer (IPv6 unicast
configuring BGP update sending delay, 213
configuring IP routing BGP, 189
configuring IP routing BGP 6PE, 252 configuring IP routing BGP 6PE basics, 252
configuring IP routing BGP 6PE optional
configuring IP routing BGP AS_PATH attribute,
configuring IP routing BGP basics, 191
configuring IP routing BGP confederation, 244
configuring IP routing BGP confederation
configuring IP routing BGP FRR, 249
configuring IP routing BGP GR, 245
462
configuring IP routing BGP GR helper, 245 configuring IP routing BGP GR restarter, 245
configuring IP routing BGP GTSM, 235
configuring IP routing BGP large-scale
configuring IP routing BGP MED attribute, 217
configuring IP routing BGP NSR, 246
configuring IP routing BGP peer, 192
configuring IP routing BGP peer group, 195
configuring IP routing BGP route filtering
configuring IP routing BGP route reflection,
configuring IP routing BGP route
configuring IP routing BGP soft reset, 236
configuring IP routing ECMP route max
configuring IP routing FIB route max lifetime, 4
configuring IP routing IPv6 IS-IS route control,
configuring IP routing IS-IS, 153
configuring IP routing IS-IS circuit level, 133
configuring IP routing IS-IS FRR automatic
backup next hop calculation, 151
configuring IP routing IS-IS FRR BFD, 152
configuring IP routing IS-IS IS level, 133
configuring IP routing RIB label max lifetime, 4
configuring IP routing RIB route max lifetime,
configuring IP routing RIP, 40 configuring IP routing RIP basics, 40
configuring IP routing RIP BFD (bidirectional
detection/control packet mode), 54
configuring IP routing RIP BFD (single-hop
configuring IP routing RIP BFD (single-hop
echo detection/specific destination), 51
configuring IP routing RIP FRR, 57
configuring IP routing RIP interface additional
configuring IP routing RIP route redistribution,
configuring IP routing RIP summary route
configuring IP routing static route, 13
configuring IPv4 BGP AS number substitution,
configuring IPv4 BGP basics, 257
configuring IPv4 BGP COMMUNITY,
463
configuring IPv4 BGP confederation, 275
configuring IPv4 BGP default local preference,
configuring IPv4 BGP holdtime, 228 configuring IPv4 BGP keepalive interval, 228
configuring IPv4 BGP load balancing, 267
configuring IPv4 BGP MED default value, 217
configuring IPv4 BGP NEXT_HOP attribute, 221
configuring IPv4 BGP path selection, 279
configuring IPv4 BGP route dampening, 214
configuring IPv4 BGP route distribution filtering
configuring IPv4 BGP route preference, 215
configuring IPv4 BGP route reception filtering
configuring IPv4 BGP route reflector,
configuring IPv4 BGP route summarization, 264
configuring IPv4 BGP route summarization
configuring IPv4 BGP route summarization
configuring IPv4 BGP route update interval, 229
configuring IPv4 BGP soft reset manually, 238
configuring IPv4 BGP-IGP route redistribution,
configuring IPv4 EBGP peer group, 197
configuring IPv4 IBGP peer group, 195
configuring IPv6 BGP AS number substitution,
configuring IPv6 BGP basics, 290
configuring IPv6 BGP COMMUNITY, 241
configuring IPv6 BGP default local preference,
configuring IPv6 BGP holdtime, 228
configuring IPv6 BGP IPsec, 234
configuring IPv6 BGP keepalive interval, 228
configuring IPv6 BGP load balancing, 233
configuring IPv6 BGP MED default value, 217
configuring IPv6 BGP NEXT_HOP attribute, 221
configuring IPv6 BGP packet IPsec, 306
configuring IPv6 BGP route dampening, 214
configuring IPv6 BGP route distribution filtering
configuring IPv6 BGP route preference, 215
configuring IPv6 BGP route reception filtering
configuring IPv6 BGP route reflector,
configuring IPv6 BGP route update interval,
configuring IPv6 BGP soft reset manually, 238
configuring IPv6 EBGP peer group, 197
configuring IPv6 IBGP peer group, 195
configuring IPv6 IS-IS basics,
configuring IPv6 PBR interface, 408
configuring IPv6 PBR interface (packet
configuring IPv6 PBR local, 407
configuring IPv6 PBR local (packet
configuring IPv6 PBR node action, 407 configuring IPv6 PBR node match criteria, 407
configuring IPv6 PBR policy, 406
configuring IPv6 static route, 320 configuring IPv6 static route BFD, 320
configuring IPv6 static route BFD control
configuring IPv6 static route BFD control
configuring IPv6 static route BFD echo mode
configuring IPv6 static routing, 322 configuring IPv6 static routing basics, 322
configuring IPv6 static routing BFD (direct
configuring IPv6 static routing BFD (indirect
configuring IS-IS authentication, 165
configuring IS-IS authentication (area), 148
configuring IS-IS authentication (neighbor
configuring IS-IS authentication (routing
configuring IS-IS DIS election, 158
configuring IS-IS ECMP routes max, 136
configuring IS-IS global cost, 135
configuring IS-IS interface cost, 134
configuring IS-IS interface DIS priority, 140
configuring IS-IS interface P2P network type,
configuring IS-IS link cost, 134
464
configuring IS-IS LSP parameters, 141 configuring IS-IS LSP timer, 141
configuring IS-IS LSP-calculated route filtering,
configuring IS-IS network management, 146
configuring IS-IS redistributed route filtering, 138
configuring IS-IS route control, 134
configuring IS-IS route convergence priority, 144
configuring IS-IS route filtering, 137
configuring IS-IS route leaking, 138
configuring IS-IS route redistribution,
configuring IS-IS route summarization, 136
configuring IS-IS system ID > host name
configuring IS-IS system ID > host name mapping
configuring IS-IS system ID > host name mapping
configuring OSPF authentication (area), 83 configuring OSPF authentication (interface), 83
configuring OSPF BFD detection (bidirectional
configuring OSPF BFD detection (single-hop
configuring OSPF DD packet interface MTU, 84
configuring OSPF discard route, 75
configuring OSPF DR election, 108
configuring OSPF ECMP route max, 77
configuring OSPF exit overflow interval, 85
configuring OSPF FRR backup next hop (routing
configuring OSPF FRR backup next hop
calculation (LFA algorithm), 94 configuring OSPF FRR BFD, 94
configuring OSPF GR helper, 91
configuring OSPF GR restarter, 90
configuring OSPF host route advertisement, 79
configuring OSPF interface cost, 76
configuring OSPF interface network type
configuring OSPF interface network type (NBMA),
configuring OSPF interface network type
configuring OSPF interface network type
configuring OSPF log count, 89
configuring OSPF LSDB external LSAs max
configuring OSPF LSU transmit rate, 87
configuring OSPF network management, 86
configuring OSPF network type, 71
configuring OSPF packet DSCP value, 84
configuring OSPF preference, 77
configuring OSPF prefix prioritization, 88
configuring OSPF prefix suppression, 87
configuring OSPF prefix suppression (OSPF
configuring OSPF received route filtering, 75
configuring OSPF redistributed route default
configuring OSPF route control, 74
configuring OSPF route redistribution, 99
configuring OSPF route redistribution (another
configuring OSPF route redistribution (default
configuring OSPF route summarization, 74,
configuring OSPF route summarization
configuring OSPF route summarization
configuring OSPF stub router, 82
configuring OSPF Type-3 LSA filtering, 76
configuring OSPF virtual link,
configuring OSPFv3 area parameter, 350
configuring OSPFv3 DR election, 374
configuring OSPFv3 ECMP route max, 355
configuring OSPFv3 GR helper, 364
configuring OSPFv3 GR restarter, 363
configuring OSPFv3 Inter-Area-Prefix LSA
filtering, 354 configuring OSPFv3 interface cost, 354
configuring OSPFv3 interface DR priority, 359
configuring OSPFv3 IPsec profile, 389
configuring OSPFv3 LSU transmit rate, 361
465
configuring OSPFv3 NBMA neighbor, 352
configuring OSPFv3 network management, 360
configuring OSPFv3 network type, 351
configuring OSPFv3 network type (interface), 352
configuring OSPFv3 P2MP neighbor, 352
configuring OSPFv3 preference, 355
configuring OSPFv3 prefix suppression, 362
configuring OSPFv3 prefix suppression
configuring OSPFv3 prefix suppression (OSPFv3
configuring OSPFv3 received route filtering, 354
configuring OSPFv3 redistributed route
configuring OSPFv3 redistributed route tag, 357
configuring OSPFv3 route control, 353
configuring OSPFv3 route redistribution, 377
configuring OSPFv3 route redistribution (another
configuring OSPFv3 route redistribution (default
configuring OSPFv3 route summarization, 380
configuring OSPFv3 route summarization (ABR),
configuring OSPFv3 stub router, 362
configuring OSPFv3 virtual link, 351
313, 314, 315 configuring PBR (interface), 315
configuring PBR (interface/packet type-based),
configuring PBR (local/packet type-based), 315
configuring PBR node action, 314 configuring PBR node match criteria, 314
configuring RIP additional routing metric, 28
configuring RIP BFD (bidirectional control
configuring RIP BFD (single-hop echo
configuring RIP BFD (single-hop echo
detection/specific destination), 37
configuring RIP ECMP route max number, 33
configuring RIP network management, 35 configuring RIP packet send rate, 35
configuring RIP poison reverse, 32
configuring RIP preference, 31
configuring RIP received/redistributed route
configuring RIP route control, 28
configuring RIP route redistribution, 31
configuring RIP split horizon, 32 configuring RIP timers, 32
configuring RIPng ECMP route max, 336
configuring RIPng IPsec profile configuration,
configuring RIPng packet zero field check,
configuring RIPng poison reverse, 335
configuring RIPng preference, 334
configuring RIPng received/redistributed route
configuring RIPng route control, 333
configuring RIPng route redistribution, 335,
configuring RIPng route summarization, 333 configuring RIPng routing metric, 333
configuring RIPng split horizon, 335 configuring RIPng timer, 335
configuring RIPv2 message authentication, 34
configuring RIPv2 route summarization, 29
configuring routing policy, 416
configuring routing policy (IPv4 route
configuring routing policy (IPv6 route
configuring routing policy apply clause, 418
configuring routing policy AS_PATH list, 415
configuring routing policy COMMUNITY list,
configuring routing policy continue clause, 419
configuring routing policy extended
configuring routing policy filter, 414
configuring routing policy if-match clause, 416
configuring routing policy IPv4 prefix list, 414
configuring routing policy IPv6 prefix list, 415
configuring static route BFD, 9
configuring static route FRR (auto backup
466
configuring static routing basics, 13
configuring static routing BFD (direct next hop),
configuring static routing BFD (indirect next hop),
configuring static routing BFD bidirectional control
configuring static routing BFD bidirectional control
configuring static routing BFD single-hop echo
configuring static routing default route, 23
configuring static routing FRR,
configuring static routing FRR (backup next hop),
controlling IP routing BGP path selection, 214
controlling IP routing BGP route distribution, 205 controlling IP routing BGP route reception, 205
controlling IS-IS SPF calculation interval, 144
controlling RIP interface advertisement, 27 controlling RIP interface reception, 27
disabling IPv4 BGP AS_PATH optimal route
disabling IPv4 BGP session establishment, 234
disabling IPv6 BGP AS_PATH optimal route
disabling IPv6 BGP session establishment, 234
disabling IS-IS interface packet send/receive, 141
disabling OSPF interface packet send/receive, 82
disabling OSPFv3 interface packet send/receive,
disabling RIP host route reception, 29
displaying IP routing BGP, 254
displaying IP routing table, 6
displaying IPv4 BGP, 254 displaying IPv6 BGP, 254
displaying IPv6 static routing, 322
displaying routing policy, 420
enabling IP routing BGP route flapping
enabling IP routing BGP session state change
enabling IP routing BGP SNMP notification,
enabling IP routing EBGP direct connections
enabling IP routing ECMP enhanced mode, 5
enabling IP routing RIP (interface), 27
enabling IP routing RIP (network), 26
enabling IPv4 BGP 4-byte AS number
enabling IPv4 BGP load balancing, 233
enabling IPv4 BGP MED AS route comparison
enabling IPv4 BGP MED AS route comparison
enabling IPv4 BGP MED AS route comparison
enabling IPv4 BGP multiple hop EBGP
enabling IPv4 BGP peer MD5 authentication,
enabling IPv4 BGP route-refresh, 236
enabling IPv6 BGP 4-byte AS number
enabling IPv6 BGP MED AS route comparison
enabling IPv6 BGP MED AS route comparison
enabling IPv6 BGP MED AS route comparison
enabling IPv6 BGP multiple hop EBGP
enabling IPv6 BGP peer MD5 authentication,
enabling IPv6 BGP route-refresh, 236
enabling IS-IS automatic cost calculation, 135
enabling IS-IS interface hello packet send,
enabling IS-IS LSP flash flooding, 143 enabling IS-IS LSP fragment extension, 143
enabling IS-IS neighbor state change logging,
enabling IS-IS PPP interface hello packet
enabling OSPF (on interface), 69
enabling OSPF (on network), 68
467
enabling OSPF neighbor state change logging, 85
enabling OSPF RFC 1583 compatibility, 85
enabling OSPFv3 neighbor state change logging,
enabling RIP poison reverse, 33 enabling RIP split horizon, 33
enabling RIP update source IP address check, 34 enabling RIPv1 message zero field check, 34
enabling RIPv2 automatic route summarization,
enabling static routing FRR BFD echo packet
enabling support for IPv6 routes with prefixes
enhancing IS-IS network security, 147
generating IP routing BGP route, 203
ignoring IP routing BGP first AS number of EBGP
ignoring IPv4 BGP ORIGINATOR_ID attribute,
ignoring IPv6 BGP ORIGINATOR_ID attribute,
ignoring OSPFv3 DD packet MTU check, 359
injecting IPv4 BGP local network, 203 injecting IPv6 BGP local network, 203
limiting IPv4 BGP routes received from peer/peer
limiting IPv6 BGP routes received from peer/peer
maintaining IP routing BGP, 254
maintaining IP routing table, 6
maintaining IPv4 BGP, 254 maintaining IPv6 BGP, 254
maintaining routing policy, 420
optimizing IP routing BGP network, 228
optimizing IPv6 IS-IS networks, 396
optimizing IS-IS networks, 139
optimizing OSPFv3 network, 357
permitting IPv4 BGP local AS number
permitting IPv6 BGP local AS number
protecting IPv4 EBGP peer (low memory
protecting IPv6 EBGP peer (low memory
redistributing IPv4 BGP IGP routes, 204 redistributing IPv6 BGP IGP routes, 204
removing IPv4 BGP private AS number from
EBGP peer/peer group update, 226
removing IPv6 BGP private AS number from
EBGP peer/peer group update, 226
saving IPv4 BGP route update, 237 saving IPv6 BGP route update, 237
setting IS-IS LSDB overload bit, 144
setting RIP packet max length, 36
specifying IP routing BGP TCP connection
specifying IPv4 BGP received route preferred
specifying IPv6 BGP received route preferred
specifying IS-IS CSNP packet send interval,
specifying IS-IS hello multiplier, 139
specifying IS-IS hello packet send interval,
specifying IS-IS LSP length, 142
specifying IS-IS preference, 135
specifying OSPF LSA arrival interval, 81 specifying OSPF LSA generation interval, 81
specifying OSPF LSA transmission delay, 80
specifying OSPF SPF calculation interval, 81
specifying OSPFv3 LSA generation interval,
specifying OSPFv3 LSA transmission delay,
specifying OSPFv3 SPF calculation interval,
troubleshooting IP routing BGP peer
troubleshooting OSPF incorrect routing
troubleshooting OSPF no neighbor
tuning IP routing BGP network, 228
tuning IP routing OSPF network, 79
tuning IP routing RIP networks, 32
tuning IPv6 IS-IS network, 396
protecting
IPv4 EBGP peer (low memory exemption), 240
IPv6 EBGP peer (low memory exemption), 240
protocols and standards
IP routing dynamic routing protocols, 2
OSPF RFC 1583 compatibility, 85
R rate
receiving
IPv4 BGP routes received from peer/peer group,
IPv6 BGP routes received from peer/peer group,
IS-IS interface packet send/receive, 141
OSPF interface packet send/receive disable, 82
OSPFv3 interface packet send/receive disable,
RIPng received/redistributed route filtering, 334
recursion
IP routing BGP route recursion, 182, 182
redistributing
IP routing BGP route generation, 203
IP routing BGP route summarization, 205
IP routing extension attribute redistribution, 3
IP routing RIP route redistribution, 43
IP routing route redistribution, 3
IPv4 BGP-IGP route redistribution, 261
IS-IS redistributed route filtering, 138
OSPF redistributed route default parameters, 78
OSPF route redistribution (default route), 78
OSPF route redistribution configuration, 99
468
OSPFv3 redistributed route tag, 357
OSPFv3 route (another routing protocol), 356
OSPFv3 route (default route), 356
OSPFv3 route redistribution, 356
RIP received/redistributed route filtering, 30
RIPng received/redistributed route filtering,
reflecting
IP routing BGP route reflector, 184
removing
IPv4 BGP private AS number removal, 226
IPv6 BGP private AS number, 226
restrictions
RFC 1583 compatibility (OSPF), 85
RIB
IP routing FIB route max lifetime, 4
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
additional routing metric configuration, 28
BFD configuration (bidirectional control
BFD configuration (bidirectional
detection/control packet mode), 54
BFD configuration (single-hop echo
BFD configuration (single-hop echo
BFD configuration (single-hop echo
detection/specific destination),
default route advertisement, 30
FRR configuration restrictions, 39
GR restarter configuration, 36
host route reception disable, 29
interface additional metric configuration, 45
interface advertisement control, 27 interface reception control, 27
IPv6.
neighbor specification, 35 network management configuration, 35
network optimization, 32 network tuning, 32
packet send rate configuration, 35
poison reverse configuration, 32
received/redistributed route filtering, 30
RIPv1 message zero field check enable, 34
RIPv2 message authentication configuration, 34
RIPv2 route summarization configuration, 29
route control configuration, 28
route redistribution configuration, 31
split horizon configuration, 32
summary route advertisement configuration, 46
update source IP address check, 34
default route advertisement, 334
IPsec profile application, 337
IPsec profile configuration, 344
network optimization, 335 network tuning, 335
poison reverse configuration, 335
received/redistributed route filtering, 334
route redistribution configuration, 335
469
route summarization, 333 routing metric configuration, 333
split horizon configuration, 335 timer configuration, 335
RIPv1
message zero field check enable, 34
RIPv2
automatic route summarization enable, 29
message authentication configuration, 34
route summarization configuration, 29 summary route advertisement, 29
route
IP routing BGP default route advertisement to
IP routing BGP optimal route advertisement
IP routing BGP route advertisement rules, 182
IP routing BGP route dampening, 184
IP routing BGP route filtering policies, 209
IP routing BGP route generation, 203
IP routing BGP route recursion, 182
IP routing BGP route reflection, 242
IP routing BGP route reflector, 184
IP routing BGP route selection, 182, 182
IP routing BGP route summarization, 184
IP routing BGP route-refresh message, 178
IP routing ECMP route max number, 5
IP routing FIB route max lifetime, 4
IP routing FIB table optimal routes, 1
IP routing RIB label max lifetime, 4
IP routing RIB route max lifetime, 4
IP routing RIP route redistribution, 43
IP routing route preference, 2
IP routing route redistribution, 3
IPv4 BGP IGP route redistribution, 204
470
IPv4 BGP MED AS route comparison
IPv4 BGP MED AS route comparison (diff ASs),
IPv4 BGP MED AS route comparison (per-AS),
IPv4 BGP ORIGINATOR_ID attribute, 243
IPv4 BGP route distribution filtering policies, 209
IPv4 BGP route reception filtering policies, 211
IPv4 BGP route summarization, 264
IPv4 BGP route update interval, 229
IPv4 BGP route update save, 237
IPv4 BGP routes received from peer/peer group,
IPv4 BGP-IGP route redistribution, 261
IPv6 BGP IGP route redistribution, 204
IPv6 BGP MED AS route comparison
IPv6 BGP MED AS route comparison (diff ASs),
IPv6 BGP MED AS route comparison (per-AS),
IPv6 BGP ORIGINATOR_ID attribute, 243
IPv6 BGP route distribution filtering policies, 209
IPv6 BGP route reception filtering policies, 211
IPv6 BGP route update interval, 229
IPv6 BGP route update save, 237
IPv6 BGP routes received from peer/peer group,
IPv6 default route configuration, 330
IPv6 IS-IS route convergence priority, 396
IPv6 static route BFD configuration, 320
IPv6 static route BFD control mode (direct next
IPv6 static route BFD control mode (indirect next
IPv6 static route BFD echo mode (single hop),
IPv6 static route configuration, 320
IPv6 static routing basic configuration, 322
IPv6 static routing BFD (direct next hop), 324
IPv6 static routing BFD (indirect next hop), 327
IPv6 static routing configuration,
IS-IS default route advertisement, 136
IS-IS LSP-calculated route filtering, 137
IS-IS redistributed route filtering, 138
IS-IS route summarization, 136
OSPF area configuration (NSSA), 106
OSPF area configuration (stub), 103
OSPF discard route configuration, 75
OSPF host route advertisement, 79
OSPF received route filtering, 75
OSPF route redistribution configuration, 99
OSPF route summarization configuration, 100
OSPFv3 received route filtering, 354
OSPFv3 redistributed route summarization
OSPFv3 route summarization (ABR), 353
RIP default route advertisement, 30
RIP host route reception disable, 29
RIP poison reverse configuration, 32
RIP preference configuration, 31
RIP received/redistributed route filtering, 30
RIP route control configuration, 28
RIP route redistribution configuration, 31
RIP split horizon configuration, 32
RIP update source IP address check, 34
RIPng default route advertisement, 334
RIPng received/redistributed route filtering,
RIPng route summarization, 333
RIPv1 message zero field check, 34
RIPv2 summary route advertisement, 29
static routing basic configuration, 13
static routing BFD configuration, 9
static routing BFD configuration (direct next hop),
static routing BFD configuration (indirect next
static routing configuration, 8, 8
static routing default route configuration, 23
static routing FRR configuration,
router
IP routing IS-IS circuit level, 133
IP routing IS-IS IS level, 133
IS-IS basics configuration, 153
IS-IS DIS election configuration, 158
IS-IS interface P2P network type, 133
IS-IS route redistribution, 162
routing
IPv6 default route.
See under IPv6 static routing
IPv6 IS-IS.
IPv6 policy-based routing.
IPv6 static routing.
policy-based routing.
Routing Information Protocol.
routing policy
471
rule
IP routing BGP route advertisement rules, 182
S saving
security
IP routing BGP GTSM configuration, 235
IS-IS authentication (area), 148
IS-IS authentication (neighbor relationship),
IS-IS authentication (routing domain), 148
IS-IS network security enhancement, 147
OSPF authentication (area), 83
OSPF authentication (interface), 83
OSPF prefix prioritization, 88
OSPFv3 IPsec profile application, 365
OSPFv3 IPsec profile configuration, 389
OSPFv3 prefix suppression, 362
RIPng IPsec profile application, 337
SEL
RIPng IPsec profile configuration, 344
selecting
IP routing BGP path selection, 214
IP routing BGP route selection, 182
sending
IS-IS CSNP packet send interval, 140
IS-IS hello packet send interval, 139
IS-IS interface hello packet send, 141
IS-IS interface packet send/receive, 141
OSPF interface packet send/receive disable,
OSPFv3 interface packet send/receive
session
IP routing BGP session state change logging,
IPv4 BGP multiple hop EBGP session
IPv4 BGP session establishment disable, 234
IPv6 BGP multiple hop EBGP session
IPv6 BGP session establishment disable, 234
setting
SNMP
IP routing BGP SNMP notification enable, 246
soft reset
IP routing BGP soft reset, 236
IPv4 BGP manual configuration, 238
IPv6 BGP manual configuration, 238
source
IS-IS PPP interface hello packet source address
RIP source IP address check, 34
speaker
specifying
IP routing BGP TCP connection source address,
IPv4 BGP received route preferred value, 214
IPv6 BGP received route preferred value, 214
IS-IS CSNP packet send interval, 140
IS-IS hello packet send interval, 139
OSPF LSA generation interval, 81
OSPF LSA transmission delay, 80
OSPF SPF calculation interval, 81
OSPFv3 LSA generation interval, 359
OSPFv3 LSA transmission delay, 358
OSPFv3 SPF calculation interval, 358
SPF
IS-IS calculation interval, 144
OSPF SPF calculation interval, 81
OSPFv3 SPF calculation interval, 358
state
IP routing BGP session state change logging, 247
OSPF neighbor state change logging, 85
static
IS-IS system ID > host name mapping, 145
routing.
static routing
472
BFD configuration (direct next hop), 15
BFD configuration (indirect next hop), 17
default route configuration, 23
IPv6.
static routing BFD bidirectional control mode
static routing BFD bidirectional control mode
(indirect next hop), 9 static routing BFD configuration, 9
static routing BFD single-hop echo mode, 10
stub
static routing FRR configuration, 11
OSPF area configuration (stub), 70
substituting
IPv4 BGP AS number substitution, 225
IPv6 BGP AS number substitution, 225
summarizing
IP routing BGP route summarization,
IPv4 BGP route summarization, 264
IPv4 BGP route summarization (automatic),
IPv4 BGP route summarization (manual), 206
IS-IS route summarization, 136
OSPF route summarization configuration, 100
OSPFv3 redistributed route summarization
OSPFv3 route summarization (ABR), 353
RIPng route summarization, 333
RIPv2 automatic route summarization enable,
RIPv2 route summarization configuration, 29
RIPv2 summary route advertisement, 29
suppressing
IPv4 BGP 4-byte AS number suppression,
IPv6 BGP 4-byte AS number suppression,
OSPFv3 prefix suppression, 362
switch
IP routing IS-IS configuration, 153
switchover
system
IS-IS system ID > host name mapping, 145
T table
tag
TCP
OSPFv3 redistributed route tag, 357
IP routing BGP TCP connection source address,
IPv4 BGP route summarization, 264
IPv4 BGP-IGP route redistribution, 261
threshold
IPv4 EBGP peer protection (level 2 threshold
time
IPv6 EBGP peer protection (level 2 threshold
timeout
timer
IS-IS LSP timer configuration, 141
OSPF LSA retransmission packet timer, 79
473
RIPng timer configuration, 335
TLV
IPv6 IS-IS basic configuration, 397
IPv6 IS-IS BFD configuration, 401
topology
IPv6 default route configuration, 330
IPv6 static route configuration, 320
IPv6 static routing basic configuration, 322
IPv6 static routing BFD (direct next hop), 324
IPv6 static routing BFD (indirect next hop),
IPv6 static routing configuration,
Track
static routing configuration, 8
transmitting
trapping
IP routing BGP SNMP notification enable, 246
OSPFv3 network management, 360
triggered RIP
triggering
troubleshooting
IP routing BGP peer connection state, 310
OSPF incorrect routing information, 124
OSPF no neighbor relationship established,
TTL
IP routing BGP GTSM configuration, 235
tuning
tunneling
Type 1 external
Type 2 external
U
UDP
IP routing RIP configuration, 40
RIPng IPsec profile configuration, 344
RIPng route redistribution, 341
unicast
IP routing dynamic routing protocols, 2
IP routing extension attribute redistribution, 3
IP routing route preference, 2
IP routing route redistribution, 3
updating
IP routing BGP update message, 178
IPv4 BGP route update interval, 229
IPv6 BGP route update interval, 229
RIP source IP address check, 34
V value
IP routing BGP received route preferred value,
IPv4 BGP MED default value, 217
IPv6 BGP MED default value, 217
virtual
OSPF virtual link configuration, 112
474
Z zero field check
475
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