Aruba JH321A HPE DataCenter Switch Installation Guide
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HPE FlexFabric 5950 Switch Series
ACL and QoS Configuration Guide
Part number: 5200-2201a
Software version: Release 6123 and later
Document version: 6W101-20170120
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Contents
Configuring ACLs ·············································································1
QoS overview ················································································ 14
Configuring a QoS policy ································································· 17
Configuring priority mapping ····························································· 23
i
Configuring traffic policing, GTS, and rate limit ····································· 30
Configuring congestion management·················································· 40
Configuring congestion avoidance ····················································· 47
Configuring traffic filtering ································································ 53
Configuring priority marking ······························································ 56
Configuring nesting ········································································· 60
ii
Configuring traffic redirecting ···························································· 64
Configuring global CAR ··································································· 69
Configuring class-based accounting ··················································· 71
Appendixes ··················································································· 75
Configuring data buffers ·································································· 81
Configuring time ranges ··································································· 86
Document conventions and icons ······················································ 88
Support and other resources····························································· 90
Index ··························································································· 92
iii
Configuring ACLs
Overview
An access control list (ACL) is a set of rules for identifying traffic based on criteria such as source IP address, destination IP address, and port number. The rules are also called permit or deny statements.
ACLs are primarily used for packet filtering. " Configuring packet filtering with ACLs " provides an
example. You can use ACLs in QoS, security, routing, and other modules for identifying traffic. The packet drop or forwarding decisions depend on the modules that use ACLs.
ACL types
Type
Basic ACLs
Advanced ACLs
Layer 2 ACLs
ACL number IP version
IPv4
2000 to 2999
IPv6
3000 to 3999
4000 to 4999
IPv4
IPv6
IPv4 and IPv6
Match criteria
Source IPv4 address.
Source IPv6 address.
Source IPv4 address, destination IPv4 address, packet priority, protocol number, and other Layer 3 and Layer 4 header fields.
Source IPv6 address, destination IPv6 address, packet priority, protocol number, and other Layer 3 and Layer 4 header fields.
Layer 2 header fields, such as source and destination MAC addresses, 802.1p priority, and link layer protocol type.
Numbering and naming ACLs
When creating an ACL, you must assign it a number or name for identification. You can specify an existing ACL by its number or name. Each ACL type has a unique range of ACL numbers.
For an IPv4 basic or advanced ACL, its ACL number or name must be unique in IPv4. For an IPv6 basic or advanced ACL, its ACL number and name must be unique in IPv6. For a Layer 2 ACL, its number or name must be globally unique.
Match order
The rules in an ACL are sorted in a specific order. When a packet matches a rule, the device stops the match process and performs the action defined in the rule. If an ACL contains overlapping or conflicting rules, the matching result and action to take depend on the rule order.
The following ACL match orders are available:
• config —Sorts ACL rules in ascending order of rule ID. A rule with a lower ID is matched before a rule with a higher ID. If you use this method, check the rules and their order carefully.
• auto —Sorts ACL rules in depth-first order. Depth-first ordering makes sure any subset of a rule
is always matched before the rule. Table 1 lists the sequence of tie breakers that depth-first
ordering uses to sort rules for each type of ACL.
1
Table 1 Sort ACL rules in depth-first order
ACL type
IPv4 basic ACL
Sequence of tie breakers
1. VPN instance.
2. More 0s in the source IPv4 address wildcard (more 0s means a narrower
IPv4 address range).
3. Rule configured earlier.
IPv4 advanced ACL
IPv6 basic ACL
IPv6 advanced ACL
Layer 2 ACL
1. VPN instance.
2. Specific protocol number.
3. More 0s in the source IPv4 address wildcard mask.
4. More 0s in the destination IPv4 address wildcard.
5. Narrower TCP/UDP service port number range.
6. Rule configured earlier.
1. VPN instance.
2. Longer prefix for the source IPv6 address (a longer prefix means a narrower IPv6 address range).
3. Rule configured earlier.
1. VPN instance.
2. Specific protocol number.
3. Longer prefix for the source IPv6 address.
4. Longer prefix for the destination IPv6 address.
5. Narrower TCP/UDP service port number range.
6. Rule configured earlier.
1. More 1s in the source MAC address mask (more 1s means a smaller
MAC address).
2. More 1s in the destination MAC address mask.
3. Rule configured earlier.
A wildcard mask, also called an inverse mask, is a 32-bit binary number represented in dotted decimal notation. In contrast to a network mask, the 0 bits in a wildcard mask represent "do care" bits, and the 1 bits represent "don't care" bits. If the "do care" bits in an IP address are identical to the
"do care" bits in an IP address criterion, the IP address matches the criterion. All "don't care" bits are ignored. The 0s and 1s in a wildcard mask can be noncontiguous. For example, 0.255.0.255 is a valid wildcard mask.
Rule numbering
ACL rules can be manually numbered or automatically numbered. This section describes how automatic ACL rule numbering works.
Rule numbering step
If you do not assign an ID to the rule you are creating, the system automatically assigns it a rule ID.
The rule numbering step sets the increment by which the system automatically numbers rules. For example, the default ACL rule numbering step is 5. If you do not assign IDs to rules you are creating, they are automatically numbered 0, 5, 10, 15, and so on. The wider the numbering step, the more rules you can insert between two rules.
By introducing a gap between rules rather than contiguously numbering rules, you have the flexibility of inserting rules in an ACL. This feature is important for a config-order ACL, where ACL rules are matched in ascending order of rule ID.
Automatic rule numbering and renumbering
The ID automatically assigned to an ACL rule takes the nearest higher multiple of the numbering step to the current highest rule ID, starting with 0.
2
For example, if the step is 5, and there are five rules numbered 0, 5, 9, 10, and 12, the newly defined rule is numbered 15. If the ACL does not contain a rule, the first rule is numbered 0.
Whenever the step changes, the rules are renumbered, starting from 0. For example, changing the step from 5 to 2 renumbers rules 5, 10, 13, and 15 as rules 0, 2, 4, and 6.
Fragment filtering with ACLs
Traditional packet filtering matches only first fragments of packets, and allows all subsequent non-first fragments to pass through. Attackers can fabricate non-first fragments to attack networks.
To avoid risks, the ACL feature is designed as follows:
•
Filters all fragments by default, including non-first fragments.
•
Allows for matching criteria modification for efficiency. For example, you can configure the ACL to filter only non-first fragments.
ACL configuration restrictions and guidelines
Matching packets are forwarded through slow forwarding if an ACL rule contains match criteria or has functions enabled in addition to the following match criteria and functions:
•
Source and destination IP addresses.
•
Source and destination ports.
•
Transport layer protocol.
•
ICMP or ICMPv6 message type, message code, and message name.
•
VPN instance.
•
Logging.
•
Time range.
Slow forwarding requires packets to be sent to the control plane for forwarding entry calculation, which affects the device forwarding performance.
Configuration task list
Tasks at a glance
(Required.) Configure ACLs according to the characteristics of the packets to be matched:
Configuring an IPv6 basic ACL
Configuring an IPv4 advanced ACL
Configuring an IPv6 advanced ACL
(Optional.) Configuring packet filtering with ACLs
Configuring a basic ACL
This section describes procedures for configuring IPv4 and IPv6 basic ACLs.
3
Configuring an IPv4 basic ACL
IPv4 basic ACLs match packets based only on source IP addresses.
To configure an IPv4 basic ACL:
Step
4. Enter system view.
Command system-view
5. Create an IPv4 basic ACL and enter its view. acl basic { acl-number
| name acl-name } [ match-order
{ auto | config } ]
Remarks
N/A
By default, no ACLs exist.
The value range for a numbered
IPv4 basic ACL is 2000 to 2999.
Use the acl basic acl-number command to enter the view of a numbered IPv4 basic ACL.
Use the acl basic name acl-name command to enter the view of a named IPv4 basic ACL.
6. (Optional.) Configure a description for the IPv4 basic ACL.
7. (Optional.) Set the rule numbering step. description text
By default, an IPv4 basic ACL does not have a description.
8. Create or edit a rule.
9. (Optional.) Add or edit a rule comment. step rule step-value [ start start-value
rule-id comment text
]
By default, the rule numbering step is 5 and the start rule ID is 0. rule [ rule-id ] { deny | permit }
[ counting | fragment | logging
| source
{ source-address source-wildcard
| any }
| time-range time-range-name
| vpn-instance vpn-instance-name ]
*
By default, no IPv4 basic ACL rules exist.
The logging keyword takes effect only when the module (for example, packet filtering) that uses the ACL supports logging.
When an IPv4 basic ACL is used for QoS traffic classification or packet filtering in a VXLAN network, the ACL matches packets as follows:
•
If the ACL is applied to the outgoing VXLAN packets on a VTEP, the
ACL matches outer
IPv4 header information.
•
If the ACL is applied to the incoming VXLAN packets on a VTEP, the
ACL matches inner
IPv4 header information.
•
If the ACL is applied to the incoming VXLAN packets on an intermediate transport device, the ACL matches outer IPv4 header information.
By default, no rule comment is configured.
4
Configuring an IPv6 basic ACL
IPv6 basic ACLs match packets based only on source IP addresses.
To configure an IPv6 basic ACL:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Create an IPv6 basic ACL view and enter its view. acl ipv6 basic { acl-number
| name acl-name } [ match-order
{ auto | config } ]
By default, no ACLs exist.
The value range for a numbered
IPv6 basic ACL is 2000 to 2999.
Use the acl ipv6 basic acl-number command to enter the view of a numbered IPv6 basic ACL.
Use the acl ipv6 basic name acl-nam e command to enter the view of a named IPv6 basic ACL.
3. (Optional.) Configure a description for the IPv6 basic
ACL.
4. (Optional.) Set the rule numbering step. description text step step-value start-value ]
[ start
By default, an IPv6 basic ACL does not have a description.
By default, the rule numbering step is 5 and the start rule ID is 0.
5. Create or edit a rule. rule [ rule-id ] { deny | permit }
[ counting | fragment | logging
| routing [ type routing-type ]
| source
{ source-address source-prefix
| source-address / source-prefix
| any }
| time-range time-range-name
| vpn-instance vpn-instance-nam e ] *
By default, no IPv6 basic ACL rules exist.
The logging keyword takes effect only when the module (for example, packet filtering) that uses the ACL supports logging.
6. (Optional.) Add or edit a rule comment. rule rule-id comment text
By default, no rule comment is configured.
Configuring an advanced ACL
This section describes procedures for configuring IPv4 and IPv6 advanced ACLs.
Configuring an IPv4 advanced ACL
IPv4 advanced ACLs match packets based on the following criteria:
•
Source IP addresses.
•
Destination IP addresses.
•
Packet priorities.
•
Protocol numbers.
•
Other protocol header information, such as TCP/UDP source and destination port numbers,
TCP flags, ICMP message types, and ICMP message codes.
Compared to IPv4 basic ACLs, IPv4 advanced ACLs allow more flexible and accurate filtering.
5
To configure an IPv4 advanced ACL:
Step
1. Enter system view.
2. Create an IPv4 advanced
ACL and enter its view.
3. (Optional.) Configure a description for the IPv4 advanced ACL.
4. (Optional.) Set the rule numbering step.
5. Create or edit a rule.
6. (Optional.) Add or edit a rule comment.
Command system-view acl advanced { acl-number
| name acl-name } [ match-order
{ auto | config } ]
Remarks
N/A
By default, no ACLs exist.
The value range for a numbered
IPv4 advanced ACL is 3000 to
3999.
Use the acl advanced acl-number command to enter the view of a numbered
IPv4 advanced ACL.
Use the acl advanced name acl-name command to enter the view of a named IPv4 advanced ACL. description text
By default, an IPv4 advanced
ACL does not have a description. step rule step-value [ start start-value
rule-id comment text
]
By default, the rule numbering step is 5 and the start rule ID is 0. rule [ rule-id ] { deny
| permit } protocol [ { { ack ack-value
| fin fin-value | psh psh-value
| rst rst-value | syn syn-value
| urg urg-value } * | established }
| counting | destination
{ dest-address dest-wildcard | any }
| destination-port operator port1
[ port2 ] | { dscp dscp |
{ precedence precedence | tos tos }
* } | fragment | icmp-type
{ icmp-type [ icmp-code ]
| icmp-message } | logging | source
{ source-address source-wildcard
| any } | source-port operator port1
[ port2 ]
| time-range time-range-name
| vpn-instance vpn-instance-name ]
*
By default, no IPv4 advanced
ACL rules exist.
The logging keyword takes effect only when the module (for example, packet filtering) that uses the ACL supports logging.
When an IPv4 advanced ACL is used for QoS traffic classification or packet filtering in a VXLAN network, the ACL matches packets as follows:
•
If the ACL is applied to the outgoing VXLAN packets on a VTEP, the
ACL matches outer
IPv4 header information.
•
If the ACL is applied to the incoming VXLAN packets on a VTEP, the
ACL matches inner
IPv4 header information.
•
If the ACL is applied to the incoming VXLAN packets on an intermediate transport device, the ACL matches outer IPv4 header information.
By default, no rule comment is configured.
6
Configuring an IPv6 advanced ACL
IPv6 advanced ACLs match packets based on the following criteria:
•
Source IPv6 addresses.
•
Destination IPv6 addresses.
•
Packet priorities.
•
Protocol numbers.
•
Other protocol header fields such as the TCP/UDP source port number, TCP/UDP destination port number, ICMPv6 message type, and ICMPv6 message code.
Compared to IPv6 basic ACLs, IPv6 advanced ACLs allow more flexible and accurate filtering.
To configure an IPv6 advanced ACL:
Step
1. Enter system view.
Command system-view
2. Create an IPv6 advanced
ACL and enter its view. acl ipv6 advanced { acl-number
| name acl-name }
[ match-order { auto | config } ]
Remarks
N/A
By default, no ACLs exist.
The value range for a numbered
IPv6 advanced ACL is 3000 to
3999.
Use the acl ipv6 advanced acl-number command to enter the view of a numbered
IPv6 advanced ACL.
Use the acl ipv6 advanced name acl-name command to enter the view of a named IPv6 advanced ACL.
3. (Optional.) Configure a description for the IPv6 advanced ACL.
4. (Optional.) Set the rule numbering step. description text
By default, an IPv6 advanced
ACL does not have a description.
5. Create or edit a rule. step step-value [ start start-value ]
By default, the rule numbering step is 5 and the start rule ID is 0. rule [ rule-id ] { deny
| permit } protocol [ { { ack ack-value
| fin fin-value | psh psh-value
| rst rst-value | syn syn-value
| urg urg-value } * | established }
| counting | destination
{ dest-address dest-prefix
| dest-address/dest-prefix | any }
| destination-port operator port1
[ port2 ] | dscp dscp
| flow-label flow-label-value
| fragment | icmp6-type
{ icmp6-type icmp6-code
| icmp6-message } | logging
| routing [ type routing-type ]
| hop-by-hop [ type hop-type ]
| source
{ source-address source-prefix
| source-address/source-prefix
| any } | source-port
| time-range time-range-name
| vpn-instance vpn-instance-name ]
*
By default, no IPv6 advanced
ACL rules exist.
The logging keyword takes effect only when the module (for example, packet filtering) that uses the ACL supports logging.
7
Step
6. (Optional.) Add or edit a rule comment.
Command rule rule-id comment text
Remarks
By default, no rule comment is configured.
Configuring a Layer 2 ACL
Layer 2 ACLs, also called "Ethernet frame header ACLs," match packets based on Layer 2 Ethernet header fields, such as:
•
Source MAC address.
•
Destination MAC address.
•
802.1p priority (VLAN priority).
•
Link layer protocol type.
•
Encapsulation type.
•
Inner source MAC address.
•
Inner destination MAC address.
•
Inner link layer protocol type.
To configure a Layer 2 ACL:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Create a Layer 2 ACL and enter its view. acl mac
[
{ acl-number match-order { auto
|
| name config acl-name
} ]
}
By default, no ACLs exist.
The value range for a numbered Layer 2 ACL is
4000 to 4999.
Use the acl mac acl-number command to enter the view of a numbered Layer 2 ACL.
Use the acl mac name acl-name command to enter the view of a named
Layer 2 ACL.
3. (Optional.) Configure a description for the Layer
2 ACL. description text
By default, a Layer 2 ACL does not have a description.
4. (Optional.) Set the rule numbering step. step step-value [ start start-value ]
By default, the rule numbering step is 5 and the start rule ID is 0.
5. Create or edit a rule. rule [ rule-id ] { deny | permit }
[ cos dot1p | counting
| dest-mac dest-address dest-mask |
{ lsap lsap-type lsap-type-mask
| type protocol-type protocol-type-mask }
| source-mac source-address source-mask
| time-range time-range-name ] *
By default, no Layer 2 ACL rules exist.
6. (Optional.) Add or edit a rule comment. rule rule-id comment text
By default, no rule comment is configured.
8
Copying an ACL
You can create an ACL by copying an existing ACL (source ACL). The new ACL (destination ACL) has the same properties and content as the source ACL, but uses a different number or name than the source ACL.
To successfully copy an ACL, make sure:
•
The destination ACL number is from the same type as the source ACL number.
•
The source ACL already exists, but the destination ACL does not.
To copy an ACL:
Step
1. Enter system view.
2. Copy an existing ACL to create a new ACL.
Command system-view acl [ ipv6 | mac ] copy { source-acl-number
| name source-acl-name } to { dest-acl-number
| name dest-acl-name }
Configuring packet filtering with ACLs
This section describes procedures for using an ACL to filter packets. For example, you can apply an
ACL to an interface to filter incoming or outgoing packets.
NOTE:
The packet filtering feature is available on Layer 2 Ethernet interfaces, Layer 2 aggregate interfaces,
Layer 3 Ethernet interfaces, Layer 3 aggregate interfaces, Layer 3 Ethernet subinterfaces, and VLAN interfaces. The term "interface" in this section collectively refers to these types of interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface
(see Layer 2—LAN Switching Configuration Guide ).
Applying an ACL to an interface for packet filtering
Step
1. Enter system view.
2. Enter interface view.
Command system-view
interface interface-type interface-number
3. Apply an ACL to the interface to filter packets. packet-filter [ ipv6 | mac ]
{ acl-number | name acl-name }
{ inbound | outbound }
[ hardware-count ]
Remarks
N/A
N/A
By default, an interface does not filter packets.
To the same direction of an interface, you can apply a maximum of three ACLs: one IPv4
ACL, one IPv6 ACL, and one
Layer 2 ACL.
You cannot apply an ACL to the outbound direction of a Layer 2 or
Layer 3 aggregate interface.
9
Configuring logging and SNMP notifications for packet filtering
You can configure the ACL module to generate log entries or SNMP notifications for packet filtering and output them to the information center or SNMP module at the output interval. The log entry or notification records the number of matching packets and the matched ACL rules. If an ACL is matched for the first time, the device immediately outputs a log entry or notification to record the matching packet.
For more information about the information center and SNMP, see Network Management and
Monitoring Configuration Guide.
To configure logging and SNMP notifications for packet filtering:
Step
1. Enter system view.
Command system-view
2. Set the interval for outputting packet filtering logs or notifications. acl { logging
| trap } interval interval
Remarks
N/A
The default setting is 0 minutes.
By default, the device does not generate log entries or SNMP notifications for packet filtering.
Setting the packet filtering default action
Step
1. Enter system view.
2. Set the packet filtering default action to deny.
Command system-view packet-filter default deny
Remarks
N/A
By default, the packet filter permits packets that do not match any ACL rule to pass.
NOTE:
The packet filtering default action does not take effect on zone pair packet filtering. The default action for zone pair packet filtering is deny .
Enabling hardware-count for the packet filtering default action
When you enable hardware-count for the packet filtering default action on an interface, the interface counts how many times the packet filtering default action is performed.
To enable the hardware-count feature for the packet filtering default action on an interface, make sure you have applied ACLs to the interface for packet filtering.
To enable hardware-count for the packet filtering default action:
Step
1. Enter system view.
2. Enter interface view.
3. Enable hardware-count for the packet filtering default
Command system-view interface interface-type interface-
number packet-filter default { inbound
| outbound } hardware-count
Remarks
N/A
N/A
By default, hardware-count is disabled for the packet filtering
10
Step action on the interface.
Command Remarks default action.
Displaying and maintaining ACLs
Execute display commands in any view and reset commands in user view.
Task
Display ACL configuration and match statistics.
Command display acl [ ipv6 | mac ] { acl-number | all | name acl-name }
Display ACL application information for packet filtering.
Display match statistics and default action statistics for packet filtering ACLs.
Display the accumulated statistics for packet filtering
ACLs. display packet-filter { interface [ interface-type interface-number ]
[ inbound | outbound ] | interface vlan-interface vlan-interface-number
[ inbound | outbound ] [ slot slot-number ] } display packet-filter statistics interface interface-type interface-number { inbound | outbound }
[ default | [ ipv6 | mac ] { acl-number | name acl-name } ] [ brief ] display
| mac ] { packet-filter acl-number | statistics name sum { acl-name inbound
} [ brief ]
| outbound } [ ipv6
Display detailed ACL packet filtering information.
Clear match statistics, accumulated match statistics, and default action statistics for packet filtering ACLs. display packet-filter verbose interface interface-type interface-number
{ inbound | outbound } [ [ ipv6 | mac ] { acl-number | name acl-name } ]
[ slot slot-number ]
Display QoS and ACL resource usage.
Clear ACL statistics. display qos-acl resource [ slot slot-number ] reset acl [ ipv6 | mac ] counter { acl-number | all | name acl-name } reset packet-filter statistics interface
[ interface-type interface-number ] { inbound | outbound } [ default |
[ ipv6 | mac ] { acl-number | name acl-name } ]
ACL configuration example
Network requirements
A company interconnects its departments through the device. Configure a packet filter to:
•
Permit access from the President's office at any time to the financial database server.
•
Permit access from the Finance department to the database server only during working hours
(from 8:00 to 18:00) on working days.
•
Deny access from any other department to the database server.
11
Figure 1 Network diagram
Financial database server
192.168.0.100/24
HGE1/0/2
Device
HGE1/0/1
HGE1/0/4
HGE1/0/3
President ' s office
192.168.1.0/24
Finance department
192.168.2.0/24
Marketing department
192.168.3.0/24
Configuration procedure
# Create a periodic time range from 8:00 to 18:00 on working days.
<Device> system-view
[Device] time-range work 08:0 to 18:00 working-day
# Create an IPv4 advanced ACL numbered 3000.
[Device] acl advanced 3000
# Configure a rule to permit access from the President's office to the financial database server.
[Device-acl-ipv4-adv-3000] rule permit ip source 192.168.1.0 0.0.0.255 destination
192.168.0.100 0
# Configure a rule to permit access from the Finance department to the database server during working hours.
[Device-acl-ipv4-adv-3000] rule permit ip source 192.168.2.0 0.0.0.255 destination
192.168.0.100 0 time-range work
# Configure a rule to deny access to the financial database server.
[Device-acl-ipv4-adv-3000] rule deny ip source any destination 192.168.0.100 0
[Device-acl-ipv4-adv-3000] quit
# Apply IPv4 advanced ACL 3000 to filter outgoing packets on interface HundredGigE 1/0/1.
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] packet-filter 3000 outbound
[Device-HundredGigE1/0/1] quit
Verifying the configuration
# Verify that a PC in the Finance department can ping the database server during working hours. (All
PCs in this example use Windows XP).
C:\> ping 192.168.0.100
Pinging 192.168.0.100 with 32 bytes of data:
12
Reply from 192.168.0.100: bytes=32 time=1ms TTL=255
Reply from 192.168.0.100: bytes=32 time<1ms TTL=255
Reply from 192.168.0.100: bytes=32 time<1ms TTL=255
Reply from 192.168.0.100: bytes=32 time<1ms TTL=255
Ping statistics for 192.168.0.100:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 1ms, Average = 0ms
# Verify that a PC in the Marketing department cannot ping the database server during working hours.
C:\> ping 192.168.0.100
Pinging 192.168.0.100 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 192.168.0.100:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
# Display configuration and match statistics for IPv4 advanced ACL 3000 on the device during working hours.
[Device] display acl 3000
Advanced IPv4 ACL 3000, 3 rules,
ACL's step is 5
rule 0 permit ip source 192.168.1.0 0.0.0.255 destination 192.168.0.100 0
rule 5 permit ip source 192.168.2.0 0.0.0.255 destination 192.168.0.100 0 time-range work (Active)
rule 10 deny ip destination 192.168.0.100 0
The output shows that rule 5 is active.
13
QoS overview
In data communications, Quality of Service (QoS) provides differentiated service guarantees for diversified traffic in terms of bandwidth, delay, jitter, and drop rate, all of which can affect QoS.
QoS manages network resources and prioritizes traffic to balance system resources.
The following section describes typical QoS service models and widely used QoS techniques.
QoS service models
This section describes several typical QoS service models.
Best-effort service model
The best-effort model is a single-service model. The best-effort model is not as reliable as other models and does not guarantee delay-free delivery.
The best-effort service model is the default model for the Internet and applies to most network applications. It uses the First In First Out (FIFO) queuing mechanism.
IntServ model
The integrated service (IntServ) model is a multiple-service model that can accommodate diverse
QoS requirements. This service model provides the most granularly differentiated QoS by identifying and guaranteeing definite QoS for each data flow.
In the IntServ model, an application must request service from the network before it sends data.
IntServ signals the service request with the RSVP. All nodes receiving the request reserve resources as requested and maintain state information for the application flow. For more information about
RSVP, see MPLS Configuration Guide .
The IntServ model demands high storage and processing capabilities because it requires all nodes along the transmission path to maintain resource state information for each flow. This model is suitable for small-sized or edge networks. However, it is not suitable for large-sized networks, for example, the core layer of the Internet, where billions of flows are present.
DiffServ model
The differentiated service (DiffServ) model is a multiple-service model that can meet diverse QoS requirements. It is easy to implement and extend. DiffServ does not signal the network to reserve resources before sending data, as IntServ does.
QoS techniques overview
The QoS techniques include the following features:
•
Traffic classification.
•
Traffic policing.
•
Traffic shaping.
•
Rate limit.
•
Congestion management.
14
•
Congestion avoidance.
The following section briefly introduces these QoS techniques.
All QoS techniques in this document are based on the DiffServ model.
Deploying QoS in a network
Figure 2 Position of the QoS techniques in a network
Traffic direction
Traffic classification
Traffic policing
Traffic policing
WAN
Congestion management
Congestion avoidance
Traffic shaping
Traffic policing
Congestion management
Congestion avoidance
Traffic shaping
Traffic policing
and congestion avoidance mainly implement the following functions:
•
Traffic classification —Uses match criteria to assign packets with the same characteristics to a traffic class. Based on traffic classes, you can provide differentiated services.
•
Traffic policing —Polices flows and imposes penalties to prevent aggressive use of network resources. You can apply traffic policing to both incoming and outgoing traffic of a port.
•
Traffic shaping —Adapts the output rate of traffic to the network resources available on the downstream device to eliminate packet drops. Traffic shaping usually applies to the outgoing traffic of a port.
•
Congestion management —Provides a resource scheduling policy to determine the packet forwarding sequence when congestion occurs. Congestion management usually applies to the outgoing traffic of a port.
•
Congestion avoidance —Monitors the network resource usage. It is usually applied to the outgoing traffic of a port. When congestion worsens, congestion avoidance reduces the queue length by dropping packets.
QoS processing flow in a device
Figure 3 briefly describes how the QoS module processes traffic.
1. Traffic classifier identifies and classifies traffic for subsequent QoS actions.
2. The QoS module takes various QoS actions on classified traffic as configured, depending on the traffic processing phase and network status. For example, you can configure the QoS module to perform the following operations:
Traffic policing for incoming traffic.
Traffic shaping for outgoing traffic.
Congestion avoidance before congestion occurs.
15
Congestion management when congestion occurs.
Figure 3 QoS processing flow
Tokens
Drop
Classify packets
CAR Mark
Other actions
Packets received on the interface
Classification
Token bucket
Traffic policing
Priority marking
Tokens
Drop Drop
Enqueue
Classify packets
CAR
GTS
Other actions
WRED Queuing
Queue 0
Queue 1
Queue 2
Dequeue
Packets sent out of the interface
Classification
Token bucket
Traffic policing Congestion avoidance
Queue N
Queues
Congestion management
Send
16
Configuring a QoS policy
You can configure some QoS features by using the MQC approach and others by using the non-MQC approach.
Non-MQC approach
In the non-MQC approach, you configure QoS service parameters without using a QoS policy. For example, you can use the rate limit feature to set a rate limit on an interface without using a QoS policy.
MQC approach
In the modular QoS configuration (MQC) approach, you configure QoS service parameters by using
QoS policies. A QoS policy defines traffic policing or other QoS actions to take on different classes of traffic. It is a set of class-behavior associations.
A traffic class is a set of match criteria for identifying traffic, and it uses the AND or OR operator.
•
If the operator is AND, a packet must match all the criteria to match the traffic class.
•
If the operator is OR, a packet matches the traffic class if it matches any of the criteria in the traffic class.
A traffic behavior defines a set of QoS actions to take on packets, such as priority marking and traffic redirecting.
By associating a traffic behavior with a traffic class in a QoS policy, you apply QoS actions in the traffic behavior to the traffic class.
Configuration procedure diagram
Figure 4 shows how to configure a QoS policy.
Figure 4 QoS policy configuration procedure
Define a class
Define a behavior
Define a policy
Apply the policy
To an interface
To VLANs
Globally
To a control plane
To a user profile
17
Defining a traffic class
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name
[ operator { and | or } ]
3. Configure a match criterion. if-match match-criteria
Remarks
N/A
By default, no traffic classes exist.
By default, no match criterion is configured.
For more information, see the if-match command in ACL and QoS Command Reference .
Defining a traffic behavior
A traffic behavior is a set of QoS actions (such as traffic filtering, policing, and priority marking) to take on a traffic class.
To define a traffic behavior:
Step
1. Enter system view.
Command system-view
2. Create a traffic behavior and enter traffic behavior view.
traffic behavior behavior-name
3. Configure an action in the traffic behavior.
See the subsequent chapters, depending on the purpose of the traffic behavior: traffic policing, traffic filtering, priority marking, class-based accounting, and so on.
Remarks
N/A
By default, no traffic behaviors exist.
By default, no action is configured for a traffic behavior.
Defining a QoS policy
To perform actions defined in a behavior for a class of packets, associate the behavior with the class in a QoS policy.
To associate a traffic class with a traffic behavior in a QoS policy:
Remarks Step
1. Enter system view.
2. Create a QoS policy and enter
QoS policy view.
3. Associ ate a
Command system-view qos policy policy-name classifier classifier-name behavior behavior-name [ insert-before before-cla
N/A
By default, no QoS policies exist.
By default, a traffic class
18
Step traffic class with a traffic behavi or to create a class-b ehavior associ ation in the
QoS policy.
Command ssifier-name ]
Remarks is not associated with a traffic behavior.
Repeat this step to create more class-behav ior associations
.
Applying the QoS policy
You can apply a QoS policy to the following destinations:
•
Interface —The QoS policy takes effect on the traffic sent or received on the interface.
•
VLAN —The QoS policy takes effect on the traffic sent or received on all ports in the VLAN.
•
Globally —The QoS policy takes effect on the traffic sent or received on all ports.
•
Control plane —The QoS policy takes effect on the traffic received on the control plane.
•
User profile —The QoS policy takes effect on the traffic sent or received by the online users of the user profile.
You can modify traffic classes, traffic behaviors, and class-behavior associations in a QoS policy even after it is applied (except that it is applied to a user profile). If a traffic class uses an ACL for traffic classification, you can delete or modify the ACL.
Applying the QoS policy to an interface
A QoS policy can be applied to multiple interfaces. However, only one QoS policy can be applied to one direction (inbound or outbound) of an interface.
The QoS policy applied to the outgoing traffic on an interface does not regulate local packets. Local packets refer to critical protocol packets sent by the local system for operation maintenance. The most common local packets include link maintenance, routing, LDP, RSVP, and SSH packets.
QoS policies can be applied to the following interfaces:
•
Layer 2 Ethernet interfaces.
•
Layer 3 Ethernet interfaces/subinterfaces.
•
Layer 2 aggregate interfaces.
•
Layer 3 aggregate interfaces.
You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide ).
To apply a QoS policy to an interface:
Step
1. Enter system view.
2. Enter interface view.
Command system-view
Remarks
N/A interface interface-type interface-number N/A
19
Step
3. Apply the QoS policy to the interface.
Command qos apply policy policy-name { inbound
| outbound }
Remarks
By default, no QoS policy is applied to an interface.
You can apply a QoS policy only to the inbound direction of a Layer 2 or Layer 3 aggregate interface.
Applying the QoS policy to VLANs
You can apply a QoS policy to VLANs to regulate traffic of the VLANs.
Configuration restrictions and guidelines
When you apply a QoS policy to VLANs, follow these restrictions and guidelines:
•
QoS policies cannot be applied to dynamic VLANs, including VLANs created by GVRP.
•
If the hardware resources of an IRF member device are insufficient, applying a QoS policy to
VLANs might fail on the IRF member device. The system does not automatically roll back the
QoS policy configuration already applied to other IRF member devices. To ensure consistency, use the undo qos vlan-policy vlan command to manually remove the QoS policy configuration applied to them.
Configuration procedure
To apply the QoS policy to VLANs:
Step
1. Enter system view.
2. Apply the QoS policy to
VLANs.
Command system-view qos vlan-policy policy-name vlan vlan-id-list { inbound | outbound }
Remarks
N/A
By default, no QoS policy is applied to a VLAN.
Applying the QoS policy globally
You can apply a QoS policy globally to the inbound or outbound direction of all ports.
If the hardware resources of an IRF member device are insufficient, applying a QoS policy globally might fail on the IRF member device. The system does not automatically roll back the QoS policy configuration already applied to other IRF member devices. To ensure consistency, use the undo qos apply policy global command to manually remove the QoS policy configuration applied to them.
To apply the QoS policy globally:
Step
1. Enter system view.
2. Apply the QoS policy globally.
Command system-view qos apply policy policy-name global { inbound | outbound }
Remarks
N/A
By default, no QoS policy is applied globally.
Applying the QoS policy to a control plane
A device provides the data plane and the control plane.
20
•
Data plane —The units at the data plane are responsible for receiving, transmitting, and switching (forwarding) packets, such as various dedicated forwarding chips. They deliver super processing speeds and throughput.
•
Control plane —The units at the control plane are processing units running most routing and switching protocols. They are responsible for protocol packet resolution and calculation, such as CPUs. Compared with data plane units, the control plane units allow for great packet processing flexibility but have lower throughput.
When the data plane receives packets that it cannot recognize or process, it transmits them to the control plane. If the transmission rate exceeds the processing capability of the control plane, the control plane will be busy handling undesired packets. As a result, the control plane will fail to handle legitimate packets correctly or timely. As a result, protocol performance is affected.
To address this problem, apply a QoS policy to the control plane to take QoS actions, such as traffic filtering or rate limiting, on inbound traffic. This ensures that the control plane can correctly receive, transmit, and process packets.
A predefined control plane QoS policy uses the protocol type or protocol group type to identify the type of packets sent to the control plane. You can use protocol types or protocol group types in if-match commands in traffic class view for traffic classification. Then you can reconfigure traffic behaviors for these traffic classes as required. You can use the display qos policy control-plane pre-defined command to display predefined control plane QoS policies.
Configuration guidelines
When you apply a QoS policy to a control plane, follow these restrictions and guidelines:
•
If the hardware resources of an IRF member device are insufficient, applying a QoS policy globally might fail on the IRF member device. The system does not automatically roll back the
QoS policy configuration already applied to other IRF member devices. To ensure consistency, use the undo qos apply policy command to manually remove the QoS policy configuration applied to them.
•
If a class uses control plane protocols or control plane protocol groups as match criteria, the action in the associated traffic behavior can only be car or the combination of car and accounting packet . Only the cir keyword in the car action can be applied correctly.
Configuration procedure
To apply the QoS policy to a control plane:
Step
1. Enter system view.
2. Enter control plane view.
3. Apply the QoS policy to the control plane.
Command system-view control-plane slot slot-number qos apply policy policy-name inbound
Remarks
N/A
N/A
By default, no QoS policy is applied to a control plane.
Applying the QoS policy to a user profile
You can apply a QoS policy to multiple user profiles. In one direction of each user profile, only one policy can be applied. To modify a QoS policy already applied to a direction, first remove the applied
QoS policy.
A user profile supports 802.1X authentication, MAC authentication, and portal authentication.
Configuration procedure
To apply a QoS policy to a user profile:
21
Step
1. Enter system view.
Command system-view
2. Enter user profile view. user-profile profile-name
3. Apply the QoS policy to the user profile. qos apply policy policy-name
{ inbound | outbound }
Remarks
N/A
The configuration made in user profile view takes effect only after it is successfully issued to the driver.
By default, no QoS policy is applied to a user profile.
Use the inbound keyword to apply the QoS policy to the incoming traffic of the device
(traffic sent by the online users). Use the outbound keyword to apply the QoS policy to the outgoing traffic of the device
(traffic received by the online users).
Displaying and maintaining QoS policies
Execute display commands in any view and reset commands in user view.
Task
Display traffic class configuration.
Display traffic behavior configuration.
Command display traffic classifier user-defined [ classifier-name ]
[ slot slot-number ] display traffic behavior user-defined [ behavior-name ]
[ slot slot-number ]
Display QoS and ACL resource usage. display qos-acl resource [ slot slot-number ]
Display QoS policy configuration. display qos policy user-defined [ policy-name
[ classifier classifier-name ] ] [ slot slot-number ]
Display information about QoS policies applied to interfaces.
Display information about QoS policies applied to user profiles. display qos policy interface [ interface-type interface-number ]
[ slot slot-number ] [ inbound | outbound ] display qos policy user-profile [ name profile-name ]
[ user-id user-id ] [ slot slot-number ] [ inbound | outbound ]
Display information about QoS policies applied to VLANs.
Display information about QoS policies applied globally. display qos vlan-policy { name policy-name | vlan vlan-id }
[ slot slot-number ] [ inbound | outbound ] display qos policy global [ slot slot-number ] [ inbound
| outbound ]
Display information about the QoS policy applied to a control plane. display qos policy control-plane slot slot-number
Display information about the predefined
QoS policy applied to the control plane. display qos policy control-plane pre-defined
[ slot slot-number ]
Clear the statistics of the QoS policy applied in a certain direction of a VLAN.
Clear the statistics for a QoS policy applied globally. reset qos vlan-policy [ vlan vlan-id reset qos policy global [ inbound |
] [ inbound outbound ]
| outbound ]
Clear the statistics for the QoS policy applied to a control plane.
reset qos policy control-plane slot slot-number
22
Configuring priority mapping
Both Layer 2 and Layer 3 Ethernet interfaces support priority mapping. The term "interface" in this chapter collectively refers to these two types of interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN
Switching Configuration Guide ).
Overview
When a packet arrives, a device assigns a set of QoS priority parameters to the packet based on either of the following:
•
A priority field carried in the packet.
•
The port priority of the incoming port.
This process is called priority mapping. During this process, the device can modify the priority of the packet according to the priority mapping rules. The set of QoS priority parameters decides the scheduling priority and forwarding priority of the packet.
Priority mapping is implemented with priority maps and involves the following priorities:
•
802.1p priority.
•
DSCP.
•
EXP.
•
IP precedence.
•
Local precedence.
•
Drop priority.
Introduction to priorities
Priorities include the following types: priorities carried in packets, and priorities locally assigned for scheduling only.
Packet-carried priorities include 802.1p priority, DSCP precedence, IP precedence, and EXP. These priorities have global significance and affect the forwarding priority of packets across the network.
For more information about these priorities, see "Appendixes."
Locally assigned priorities only have local significance. They are assigned by the device only for scheduling. These priorities include the local precedence, drop priority, and user priority, as follows:
•
Local precedence —Used for queuing. A local precedence value corresponds to an output queue. A packet with higher local precedence is assigned to a higher priority output queue to be preferentially scheduled.
•
Drop priority —Used for making packet drop decisions. Packets with the highest drop priority are dropped preferentially.
Priority maps
The device provides various types of priority maps. By looking through a priority map, the device decides which priority value to assign to a packet for subsequent packet processing.
The default priority maps (as shown in Appendix B Default priority maps ) are available for priority
mapping. They are adequate in most cases. If a default priority map cannot meet your requirements, you can modify the priority map as required.
23
Priority mapping configuration tasks
You can configure priority mapping by using any of the following methods:
•
Configuring priority trust mode —In this method, you can configure a port to look up a trusted priority type (802.1p, for example) in incoming packets in the priority maps. Then, the system maps the trusted priority to the target priority types and values.
•
Changing port priority —If no packet priority is trusted, the port priority of the incoming port is used. By changing the port priority of a port, you change the priority of the incoming packets on the port.
To configure priority mapping, perform the following tasks:
Tasks at a glance
(Optional.) Configuring a priority map
(Required.) Perform one of the following tasks:
Configuring a port to trust packet priority for priority mapping
Changing the port priority of an interface
Configuring a priority map
The device provides the following types of priority map:
Priority map dot1p-dp dot1p-exp dot1p-lp dscp-dot1p dscp-dp dscp-dscp exp-dot1p exp-dp
To configure a priority map:
Description
802.1p-drop priority map.
802.1p-EXP priority map.
802.1p-local priority map.
DSCP-802.1p priority map.
DSCP-drop priority map.
DSCP-DSCP priority map.
EXP-802.1p priority map.
EXP-drop priority map.
Step
2. Enter priority map view.
3. Configure mappings for the priority map.
Command
1. Enter system view. system-view
Remarks
N/A qos map-table { dot1p-dp | dot1p-exp
| dot1p-lp | dscp-dot1p | dscp-dp
| dscp-dscp | exp-dot1p | exp-dp }
N/A import import-value-list export export-value
By default, the default priority maps are used. For more information, see "Appendixes."
If you execute this command multiple times, the most recent configuration takes effect.
24
Configuring a port to trust packet priority for priority mapping
You can configure the device to trust a particular priority field carried in packets for priority mapping on ports or globally.
When you configure the trusted packet priority type on an interface, use the following available keywords:
• dot1p —Uses the 802.1p priority of received packets for mapping.
• dscp —Uses the DSCP precedence of received IP packets for mapping.
To configure the trusted packet priority type on an interface:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter interface view. interface interface-type interface-number N/A
3. Configure the trusted packet priority type. qos trust { dot1p | dscp }
By default, an interface does not trust any packet priority and uses its port priority as the 802.1p priority for priority mapping.
Changing the port priority of an interface
If an interface does not trust any packet priority, the device uses its port priority to look for priority parameters for the incoming packets. By changing port priority, you can prioritize traffic received on different interfaces.
To change the port priority of an interface:
Step
1. Enter system view.
2. Enter interface view.
3. Set the port priority of the interface.
Command system-view
Remarks
N/A interface interface-type interface-number N/A qos priority [ dscp ] priority-value
By default, the port priority is 0, and the DSCP value of packets is not modified.
When no priority trust mode is configured for an interface, the interface uses the port priority as the
802.1p priority for priority mapping. If the qos priority dscp priority-value command is configured, the interface modifies the
DSCP value of Layer 3 packets in addition to performing priority mapping.
25
Displaying and maintaining priority mapping
Execute display commands in any view.
Task
Display priority map configuration.
Display the trusted packet priority type on an interface.
Command display qos map-table [ dot1p-dp | dot1p-exp | dot1p-lp
| dscp-dot1p | dscp-dp | dscp-dscp | exp-dot1p | exp-dp ] display qos trust interface [ interface-type interface-number ]
Priority mapping configuration examples
Port priority configuration example
Network requirements
•
The IP precedence of traffic from Device A to Device C is 3.
•
The IP precedence of traffic from Device B to Device C is 1.
Configure Device C to preferentially process packets from Device A to the server when
HundredGigE 1/0/3 of Device C is congested.
Figure 5 Network diagram
Device A
HGE
IP precedence
/1
Internet
3
HGE
1/0
/1
1/0
/2
HGE
IP precedence
1
HGE
1/0
/2
Device C
HGE1/0/3
Server
Device B
Configuration procedure
# Assign port priority to HundredGigE 1/0/1 and HundredGigE 1/0/2. Make sure the priority of
HundredGigE 1/0/1 is higher than that of HundredGigE 1/0/2.
<DeviceC> system-view
[DeviceC] interface hundredgige 1/0/1
[DeviceC-HundredGigE1/0/1] qos priority 3
[DeviceC-HundredGigE1/0/1] quit
[DeviceC] interface hundredgige 1/0/2
[DeviceC-HundredGigE1/0/2] qos priority 1
[DeviceC-HundredGigE1/0/2] quit
26
Priority mapping table and priority marking configuration example
Network requirements
•
The Marketing department connects to HundredGigE 1/0/1 of Device, which sets the 802.1p priority of traffic from the Marketing department to 3.
•
The R&D department connects to HundredGigE 1/0/2 of Device, which sets the 802.1p priority of traffic from the R&D department to 4.
•
The Management department connects to HundredGigE 1/0/3 of Device, which sets the 802.1p priority of traffic from the Management department to 5.
Configure port priority, 802.1p-to-local mapping table, and priority marking to implement the plan as
Table 2 Configuration plan
Traffic destination
Public servers
Internet
Traffic priority order
Queuing plan
Traffic source
R&D department >
Management department > Marketing department
R&D department
Management department
4
Marketing department 2
Output queue
6
Management department > Marketing department > R&D department
R&D department
Management department
2
6
Marketing department 4
Queue priority
High
Medium
Low
Low
High
Medium
27
Figure 6 Network diagram
Internet
Host Host
Server
Management department
Data server
HGE
1/0
/3
HGE
1/
0/
2
HGE
1/
0/
4
Device
HGE
1/0
/1
Server
R&D department
Host
Mail server Server
Public servers Marketing department
Configuration procedure
1. Configure trusting port priority:
# Set the port priority of HundredGigE 1/0/1 to 3.
<Device> system-view
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] qos priority 3
[Device-HundredGigE1/0/1] quit
# Set the port priority of HundredGigE 1/0/2 to 4.
[Device] interface hundredgige 1/0/2
[Device-HundredGigE1/0/2] qos priority 4
[Device-HundredGigE1/0/2] quit
# Set the port priority of HundredGigE 1/0/3 to 5.
[Device] interface hundredgige 1/0/3
[Device-HundredGigE1/0/3] qos priority 5
[Device-HundredGigE1/0/3] quit
2. Configure the 802.1p-to-local mapping table to map 802.1p priority values 3, 4, and 5 to local precedence values 2, 6, and 4.
This guarantees the R&D department, Management department, and Marketing department decreased priorities to access the public servers.
[Device] qos map-table dot1p-lp
[Device-maptbl-dot1p-lp] import 3 export 2
[Device-maptbl-dot1p-lp] import 4 export 6
[Device-maptbl-dot1p-lp] import 5 export 4
[Device-maptbl-dot1p-lp] quit
28
3. Configure priority marking:
# Create ACL 3000, and configure a rule to match HTTP packets.
[Device] acl advance 3000
[Device-acl-adv-3000] rule permit tcp destination-port eq 80
[Device-acl-adv-3000] quit
# Create a traffic class named http , and use ACL 3000 as a match criterion.
[Device] traffic classifier http
[Device-classifier-http] if-match acl 3000
[Device-classifier-http] quit
# Create a traffic behavior named admin , and configure a marking action for the Management department.
[Device] traffic behavior admin
[Device-behavior-admin] remark dot1p 4
[Device-behavior-admin] quit
# Create a QoS policy named admin , and associate traffic class http with traffic behavior admin in QoS policy admin .
[Device] qos policy admin
[Device-qospolicy-admin] classifier http behavior admin
[Device-qospolicy-admin] quit
# Apply QoS policy admin to the inbound direction of HundredGigE 1/0/3.
[Device] interface hundredgige 1/0/3
[Device-HundredGigE1/0/3] qos apply policy admin inbound
# Create a traffic behavior named market , and configure a marking action for the Marketing department.
[Device] traffic behavior market
[Device-behavior-market] remark dot1p 5
[Device-behavior-market] quit
# Create a QoS policy named market , and associate traffic class http with traffic behavior market in QoS policy market .
[Device] qos policy market
[Device-qospolicy-market] classifier http behavior market
[Device-qospolicy-market] quit
# Apply QoS policy market to the inbound direction of HundredGigE 1/0/1.
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] qos apply policy market inbound
# Create a traffic behavior named rd , and configure a marking action for the R&D department.
[Device] traffic behavior rd
[Device-behavior-rd] remark dot1p 3
[Device-behavior-rd] quit
# Create a QoS policy named rd , and associate traffic class http with traffic behavior rd in QoS policy rd .
[Device] qos policy rd
[Device-qospolicy-rd] classifier http behavior rd
[Device-qospolicy-rd] quit
# Apply QoS policy rd to the inbound direction of HundredGigE 1/0/2.
[Device] interface hundredgige 1/0/2
[Device-HundredGigE1/0/2] qos apply policy rd inbound
29
Configuring traffic policing, GTS, and rate limit
Overview
Traffic policing helps assign network resources (including bandwidth) and increase network performance. For example, you can configure a flow to use only the resources committed to it in a certain time range. This avoids network congestion caused by burst traffic.
Traffic policing, Generic Traffic Shaping (GTS), and rate limit control the traffic rate and resource usage according to traffic specifications. You can use token buckets for evaluating traffic specifications.
Traffic evaluation and token buckets
Token bucket features
A token bucket is analogous to a container that holds a certain number of tokens. Each token represents a certain forwarding capacity. The system puts tokens into the bucket at a constant rate.
When the token bucket is full, the extra tokens cause the token bucket to overflow.
Evaluating traffic with the token bucket
A token bucket mechanism evaluates traffic by looking at the number of tokens in the bucket. If the number of tokens in the bucket is enough for forwarding the packets:
•
The traffic conforms to the specification (called conforming traffic).
•
The corresponding tokens are taken away from the bucket.
Otherwise, the traffic does not conform to the specification (called excess traffic).
A token bucket has the following configurable parameters:
•
Mean rate at which tokens are put into the bucket, which is the permitted average rate of traffic.
It is usually set to the committed information rate (CIR).
•
Burst size or the capacity of the token bucket. It is the maximum traffic size permitted in each burst. It is usually set to the committed burst size (CBS). The set burst size must be greater than the maximum packet size.
Each arriving packet is evaluated.
Complicated evaluation
You can set two token buckets, bucket C and bucket E, to evaluate traffic in a more complicated environment and achieve more policing flexibility. For example, traffic policing uses the following mechanisms:
•
Single rate two color —Uses one token bucket and the following parameters:
CIR —Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.
CBS —Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.
When a packet arrives, the following rules apply:
If bucket C has enough tokens to forward the packet, the packet is colored green.
Otherwise, the packet is colored red.
•
Single rate three color —Uses two token buckets and the following parameters:
30
CIR —Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.
CBS —Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.
EBS —Size of bucket E minus size of bucket C, which specifies the transient burst of traffic that bucket E can forward. The EBS cannot be 0. The size of E bucket is the sum of the CBS and EBS.
When a packet arrives, the following rules apply:
If bucket C has enough tokens, the packet is colored green.
If bucket C does not have enough tokens but bucket E has enough tokens, the packet is colored yellow.
If neither bucket C nor bucket E has sufficient tokens, the packet is colored red.
•
Two rate three color —Uses two token buckets and the following parameters:
CIR —Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.
CBS —Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.
PIR —Rate at which tokens are put into bucket E, which specifies the average packet transmission or forwarding rate allowed by bucket E.
EBS —Size of bucket E, which specifies the transient burst of traffic that bucket E can forward.
When a packet arrives, the following rules apply:
If bucket C has enough tokens, the packet is colored green.
If bucket C does not have enough tokens but bucket E has enough tokens, the packet is colored yellow.
If neither bucket C nor bucket E has sufficient tokens, the packet is colored red.
Traffic policing
Traffic policing supports policing the inbound traffic and the outbound traffic.
A typical application of traffic policing is to supervise the specification of traffic entering a network and limit it within a reasonable range. Another application is to "discipline" the extra traffic to prevent aggressive use of network resources by an application. For example, you can limit bandwidth for
HTTP packets to less than 50% of the total. If the traffic of a session exceeds the limit, traffic policing
can drop the packets or reset the IP precedence of the packets. Figure 7 shows an example of
policing outbound traffic on an interface.
31
Figure 7 Traffic policing
Put tokens into the bucket at the set rate
Packets to be sent out this interface
Packets sent
Classify
Token bucket
Drop
Traffic policing is widely used in policing traffic entering the ISP networks. It can classify the policed traffic and take predefined policing actions on each packet depending on the evaluation result:
•
Forwarding the packet if the evaluation result is "conforming."
•
Dropping the packet if the evaluation result is "excess."
•
Forwarding the packet with its precedence re-marked if the evaluation result is "conforming."
GTS
GTS supports shaping the outbound traffic. GTS limits the outbound traffic rate by buffering exceeding traffic. You can use GTS to adapt the traffic output rate on a device to the input traffic rate of its connected device to avoid packet loss.
The differences between traffic policing and GTS are as follows:
•
Packets to be dropped with traffic policing are retained in a buffer or queue with GTS, as shown
in Figure 8 . When enough tokens are in the token bucket, the buffered packets are sent at an
even rate.
•
GTS can result in additional delay and traffic policing does not.
32
Figure 8 GTS
Packets to be sent through this interface
Tokens are put into the bucket at the set rate
Packets sent
Packet classification
Token bucket
Queue
Packets dropped
For example, in Figure 9 , Device B performs traffic policing on packets from Device A and drops
packets exceeding the limit. To avoid packet loss, you can perform GTS on the outgoing interface of
Device A so that packets exceeding the limit are cached in Device A. Once resources are released,
GTS takes out the cached packets and sends them out.
Figure 9 GTS application
Device A Device B
Rate limit
Rate limit controls the rate of inbound and outbound traffic. The outbound traffic is taken for example.
The rate limit of an interface specifies the maximum rate for forwarding packets (including critical packets).
Rate limit also uses token buckets for traffic control. When rate limit is configured on an interface, a token bucket handles all packets to be sent through the interface for rate limiting. If enough tokens are in the token bucket, packets can be forwarded. Otherwise, packets are put into QoS queues for congestion management. In this way, the traffic passing the interface is controlled.
33
Figure 10 Rate limit implementation
Put tokens to the bucket at the set rate
Packets to be sent
Packets sent
Queue
Token bucket
Buffer
The token bucket mechanism limits traffic rate when accommodating bursts. It allows bursty traffic to be transmitted if enough tokens are available. If tokens are scarce, packets cannot be transmitted until efficient tokens are generated in the token bucket. It restricts the traffic rate to the rate for generating tokens.
Rate limit controls the total rate of all packets on an interface. It is easier to use than traffic policing in controlling the total traffic rate.
Configuring traffic policing by using the MQC approach
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name [ operator { and | or } ]
Remarks
N/A
By default, no traffic classes exist.
3. Configu re a match criterio n.
if-match match-criteria
By default, no match criterion is configured
.
For more informatio n about the if-mat ch command, see ACL and QoS
Command
Reference
34
Step Command Remarks
.
4. Return to system view.
5. Create a traffic behavi or and enter traffic behavi or view. quit
traffic behavior behavior-name
N/A
By default, no traffic behaviors exist.
6. Configu re a traffic policing action. car cir [ pps ] committed-information-rate [ cbs committed-burst-size
[ ebs excess-burst-size ] ] [ green action | red action | yellow action ] * car cir [ pps ] committed-information-rate [ cbs committed-burst-size ] pir
[ pps ] peak-information-rate [ ebs excess-burst-size ] [ green action | red action
| yellow action ] *
By default, no traffic policing action is configured
.
7. Return to system view.
8. Create a QoS policy and enter
QoS policy view.
9. Associ ate the traffic class with the traffic behavi or in the
QoS policy.
10. Return to system view. quit qos policy classifier classifier-name sifier-name quit
policy-name
]
behavior behavior-name [ insert-before before-clas
N/A
By default, no QoS policies exist.
By default, a traffic class is not associated with a traffic behavior.
N/A
11. Apply the
QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy globally
Applying the QoS policy to a control plane
Applying the QoS policy to a user profile
Choose one of the application destinatio ns as needed.
By default, no QoS policy is applied.
35
Configuring GTS by using the non-MQC approach
You can configure queue-based GTS by using the non-MQC approach.
Both Layer 2 and Layer 3 Ethernet interfaces support the queue-based GTS feature. The term
"interface" in this section collectively refers to these two types of interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer
2—LAN Switching Configuration Guide ).
To configure queue-based GTS:
Step
1. Enter system view.
2. Enter interface view.
Command system-view interface interface-type interface-number
Remarks
N/A
N/A
3. Configure GTS for a queue. qos gts queue queue-id cir committed-information-rate
[ cbs committed-burst-size ]
By default, GTS is not configured on an interface.
Configuring the rate limit for an interface
The rate limit for an interface specifies the maximum rate of incoming or outgoing packets on the interface.
Both Layer 2 and Layer 3 Ethernet interfaces support the rate limit feature. The term "interface" in this section collectively refers to these two types of interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN
Switching Configuration Guide ).
To configure the rate limit for an interface:
Remarks
N/A
Step
1. Enter system view.
Command system-view
2. Enter interface view. interface interface-type
interface-number
3. Configure the rate limit for the interface. qos lr { inbound | outbound }
cir committed-information-rate [ cbs committed-burst-size ]
N/A
By default, no rate limit is configured on an interface.
Displaying and maintaining traffic policing, GTS, and rate limit
Execute display commands in any view.
Task
Display QoS and ACL resource usage.
Display traffic behavior configuration.
Command display qos-acl resource [ slot slot-number ] display traffic behavior user-defined [ behavior-name ]
[ slot slot-number ]
36
Task Command
Display GTS configuration and statistics for interfaces. display qos gts interface [ interface-type interface-number ]
Display rate limit configuration and statistics for interfaces. display qos lr interface [ interface-type interface-number ]
Traffic policing, GTS, and rate limit configuration example
Network requirements
•
The server, Host A, and Host B can access the Internet through Device A and Device B.
•
The server, Host A, and HundredGigE 1/0/1 of Device A are in the same network segment.
•
Host B and HundredGigE 1/0/2 of Device A are in the same network segment.
Perform traffic control for the packets that HundredGigE 1/0/1 of Device A receives from the server and Host A using the following guidelines:
•
Limit the rate of packets from the server to 10240 kbps. When the traffic rate is below 10240 kbps, the traffic is forwarded. When the traffic rate exceeds 10240 kbps, the excess packets are marked with DSCP value 0 and then forwarded.
•
Limit the rate of packets from Host A to 2560 kbps. When the traffic rate is below 2560 kbps, the traffic is forwarded. When the traffic rate exceeds 2560 kbps, the excess packets are dropped.
Perform traffic control on HundredGigE 1/0/1 and HundredGigE 1/0/2 of Device B using the following guidelines:
•
Limit the incoming traffic rate on HundredGigE 1/0/1 to 20480 kbps, and the excess packets are dropped.
•
Limit the outgoing traffic rate on HundredGigE 1/0/2 to 10240 kbps, and the excess packets are dropped.
Figure 11 Network diagram
Server
1.1.1.1/8 Ethernet
Host A
Internet
1.1.1.2/8 HGE1/0/1
Device B
HGE1/0/2
Host B
HGE1/0/1
Device A
HGE1/0/3
HGE1/0/2
Configuration procedure
1. Configure Device A:
# Configure ACL 2001 and ACL 2002 to permit the packets from the server and Host A, respectively.
37
[DeviceA] acl basic 2001
[DeviceA-acl-ipv4-basic-2001] rule permit source 1.1.1.1 0
[DeviceA-acl-ipv4-basic-2001] quit
[DeviceA] acl basic 2002
[DeviceA-acl-ipv4-basic-2002] rule permit source 1.1.1.2 0
[DeviceA-acl-ipv4-basic-2002] quit
# Create a traffic class named server , and use ACL 2001 as the match criterion.
[DeviceA] traffic classifier server
[DeviceA-classifier-server] if-match acl 2001
[DeviceA-classifier-server] quit
# Create a traffic class named host , and use ACL 2002 as the match criterion.
[DeviceA] traffic classifier host
[DeviceA-classifier-host] if-match acl 2002
[DeviceA-classifier-host] quit
# Create a traffic behavior named server , and configure a traffic policing action (CIR 10240 kbps).
[DeviceA] traffic behavior server
[DeviceA-behavior-server] car cir 10240 red remark-dscp-pass 0
[DeviceA-behavior-server] quit
# Create a traffic behavior named host , and configure a traffic policing action (CIR 2560 kbps).
[DeviceA] traffic behavior host
[DeviceA-behavior-host] car cir 2560
[DeviceA-behavior-host] quit
# Create a QoS policy named car , and associate traffic classes server and host with traffic behaviors server and host in QoS policy car , respectively.
[DeviceA] qos policy car
[DeviceA-qospolicy-car] classifier server behavior server
[DeviceA-qospolicy-car] classifier host behavior host
[DeviceA-qospolicy-car] quit
# Apply QoS policy car to the inbound direction of HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] qos apply policy car inbound
2. Configure Device B:
# Create ACL 3001, and configure a rule to match HTTP packets.
<DeviceB> system-view
[DeviceB] acl advanced 3001
[DeviceB-acl-adv-3001] rule permit tcp destination-port eq 80
[DeviceB-acl-adv-3001] quit
# Create a traffic class named http , and use ACL 3001 as a match criterion.
[DeviceB] traffic classifier http
[DeviceB-classifier-http] if-match acl 3001
[DeviceB-classifier-http] quit
# Create a traffic class named class , and configure the traffic class to match all packets.
[DeviceB] traffic classifier class
[DeviceB-classifier-class] if-match any
[DeviceB-classifier-class] quit
# Create a traffic behavior named car_inbound , and configure a traffic policing action (CIR
20480 kbps).
38
[DeviceB] traffic behavior car_inbound
[DeviceB-behavior-car_inbound] car cir 20480
[DeviceB-behavior-car_inbound] quit
# Create a traffic behavior named car_outbound , and configure a traffic policing action (CIR
10240 kbps).
[DeviceB] traffic behavior car_outbound
[DeviceB-behavior-car_outbound] car cir 10240
[DeviceB-behavior-car_outbound] quit
# Create a QoS policy named car_inbound , and associate traffic class class with traffic behavior car_inbound in QoS policy car_inbound .
[DeviceB] qos policy car_inbound
[DeviceB-qospolicy-car_inbound] classifier class behavior car_inbound
[DeviceB-qospolicy-car_inbound] quit
# Create a QoS policy named car_outbound , and associate traffic class http with traffic behavior car_outbound in QoS policy car_outbound .
[DeviceB] qos policy car_outbound
[DeviceB-qospolicy-car_outbound] classifier http behavior car_outbound
[DeviceB-qospolicy-car_outbound] quit
# Apply QoS policy car_inbound to the inbound direction of HundredGigE 1/0/1.
[DeviceB] interface hundredgige 1/0/1
[DeviceB-HundredGigE1/0/1] qos apply policy car_inbound inbound
# Apply QoS policy car_outbound to the outbound direction of HundredGigE 1/0/2.
[DeviceB] interface hundredgige 1/0/2
[DeviceB-HundredGigE1/0/2] qos apply policy car_outbound outbound
39
Configuring congestion management
Overview
Congestion occurs on a link or node when traffic size exceeds the processing capability of the link or node. It is typical of a statistical multiplexing network and can be caused by link failures, insufficient resources, and various other causes.
Figure 12 shows two typical congestion scenarios.
Figure 12 Traffic congestion scenarios
100M
100M 10M 100M 10M
100M > 10M
(1)
50M
(100M + 10M + 50M) > 100M
(2)
Congestion produces the following negative results:
•
Increased delay and jitter during packet transmission.
•
Decreased network throughput and resource use efficiency.
•
Network resource (memory, in particular) exhaustion and even system breakdown.
Congestion is unavoidable in switched networks and multiuser application environments. To improve the service performance of your network, take measures to manage and control it.
The key to congestion management is defining a resource dispatching policy to prioritize packets for forwarding when congestion occurs.
Congestion management uses queuing and scheduling algorithms to classify and sort traffic leaving a port.
The switch supports the following queuing mechanisms.
SP queuing
SP queuing is designed for mission-critical applications that require preferential service to reduce the response delay when congestion occurs.
40
Figure 13 SP queuing
Queue 7
High priority
Packets to be sent through this port
Queue 6 Sent packets
Interface
……
Queue 1
Packet classification
Queue scheduling
Sending queue
Queue 0
Low priority
In Figure 13 , SP queuing classifies eight queues on a port into eight classes, numbered 7 to 0 in
descending priority order.
SP queuing schedules the eight queues in the descending order of priority. SP queuing sends packets in the queue with the highest priority first. When the queue with the highest priority is empty, it sends packets in the queue with the second highest priority, and so on. You can assign mission-critical packets to a high priority queue to make sure they are always served first. Common service packets can be assigned to low priority queues to be transmitted when high priority queues are empty.
The disadvantage of SP queuing is that packets in the lower priority queues cannot be transmitted if packets exist in the higher priority queues. In the worst case, lower priority traffic might never get serviced.
WRR queuing
WRR queuing schedules all the queues in turn to ensure that every queue is served for a certain
Figure 14 WRR queuing
Queue 0 Weight 1
Packets to be sent through this port Queue 1 Weight 2 Sent packets
Interface
……
Queue N-2 Weight N-1
Packet classification
Queue N-1 Weight N
Queue scheduling
Sending queue
41
Assume a port provides eight output queues. WRR assigns each queue a weight value (represented by w7, w6, w5, w4, w3, w2, w1, or w0). The weight value of a queue decides the proportion of resources assigned to the queue. On a 100 Mbps port, you can set the weight values to 50, 30, 10,
10, 50, 30, 10, and 10 for w7 through w0. In this way, the queue with the lowest priority can get a minimum of 5 Mbps of bandwidth. WRR solves the problem that SP queuing might fail to serve packets in low-priority queues for a long time.
Another advantage of WRR queuing is that when the queues are scheduled in turn, the service time for each queue is not fixed. If a queue is empty, the next queue will be scheduled immediately. This improves bandwidth resource use efficiency.
WRR queuing includes the following types:
•
Basic WRR queuing —Contains multiple queues. You can set the weight for each queue, and
WRR schedules these queues based on the user-defined parameters in a round robin manner.
•
Group-based WRR queuing —All the queues are scheduled by WRR. You can divide output queues to WRR priority queue group 1 and WRR priority queue group 2. Round robin queue scheduling is performed for group 1 first. If group 1 is empty, round robin queue scheduling is performed for group 2.
On an interface enabled with group-based WRR queuing, you can assign queues to the SP group.
Queues in the SP group are scheduled with SP. The SP group has higher scheduling priority than the
WRR groups.
Only group-based WRR queuing is supported in the current software version, and only WRR group 1 is supported.
WFQ queuing
Figure 15 WFQ queuing
Queue 0 Weight 1
Packets to be sent through this port Queue 1 Weight 2 Sent packets
Interface
……
Queue N-2 Weight N-1
Packet classification
Queue N-1 Weight N
Queue scheduling
Sending queue
WFQ is similar to WRR. The difference is that WFQ enables you to set guaranteed bandwidth that a
WFQ queue can get during congestion.
On an interface with WFQ queuing enabled, you can assign queues to the SP group. Queues in the
SP group are scheduled with SP. The SP group has higher scheduling priority than the WFQ groups.
Configuration task list
Both Layer 2 and Layer 3 Ethernet interfaces support the congestion management feature. The term
"interface" in this section collectively refers to these two types of interfaces. You can use the port
42
link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer
2—LAN Switching Configuration Guide ).
To achieve congestion management, perform the following tasks:
Tasks at a glance
(Required.) Perform one of the following tasks to configure congestion management:
Configuring SP queuing
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter interface view. interface interface-type interface-number N/A
3. Configure SP queuing. qos sp
By default, byte-count WRR queuing is used on an interface.
Configuring WRR queuing
Step Command
1. Enter system view. system-view
2. Enter interface view.
Remarks
N/A
interface interface-type interface-number N/A
3. Enable WRR queuing. qos wrr { byte-count | weight }
By default, byte-count WRR queuing is used on an interface.
4. Assign a queue to a WRR group, and configure scheduling parameters for the queue.
qos wrr queue-id group 1
{ byte-count | weight } schedule-value
By default, queues 0 through 7 are in
WRR group 1 and have a weight of
1, 2, 3, 4, 5, 9, 13, and 15, respectively.
Select byte-count or weight according to the WRR type
(byte-count or packet-based) you have enabled.
Configuring WFQ queuing
With a WFQ queue configured, an interface has WFQ enabled. Other queues on the interface use the default WFQ scheduling value.
To configure WFQ queuing:
Step
1. Enter system view.
Command system-view
Remarks
N/A
43
Step
2. Enter interface view.
3. Enable WFQ queuing.
Command Remarks interface interface-type interface-number N/A qos wfq { byte-count | weight }
By default, byte-count WRR queuing is used on an interface.
4. Assign a queue to a WFQ group, and configure scheduling parameters for the queue.
qos wfq queue-id group 1
{ byte-count | weight } schedule-value
By default, all queues on a
WFQ-enabled interface are in
WFQ group 1 and have a weight of 1.
Select byte-count or weight according to the WFQ type
(byte-count or packet-based) you have enabled.
5. (Optional.) Set the minimum guaranteed bandwidth for a WFQ queue.
qos bandwidth queue queue-id
min bandwidth-value
The default setting is 64 kbps.
Configuring SP+WRR queuing
Configuration procedure
To configure SP+WRR queuing:
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Enter interface view.
interface interface-type interface-number
N/A
3. Enable byte-count or packet-based WRR queuing.
4. Assign a queue to the SP group. qos wrr { byte-count
| weight } qos
wrr queue-id group sp
By default, byte-count WRR queuing is used on an interface.
By default, all queues on a WRR-enabled interface are in WRR group 1.
5. Assign a queue to the WRR group, and configure a scheduling weight for the queue. qos
wrr queue-id group 1
{ byte-count | weight } schedule-value
By default, all queues on a WRR-enabled interface are in WRR group 1, and the scheduling values of queues 0 through 7 are
1, 2, 3, 4, 5, 9, 13, and 15, respectively.
Select byte-count or weight according to the WRR type (byte-count or packet-based) you have enabled.
Configuration example
1. Network requirements
Configure SP+WRR queuing on HundredGigE 1/0/1, and use packet-based WRR.
Assign queues 4 through 7 on HundredGigE 1/0/1 to the SP group.
Assign queues 0 through 3 on HundredGigE 1/0/1 to WRR group 1, with their weights as 1,
2, 1, and 3, respectively.
2. Configuration procedure
# Enter system view.
<Sysname> system-view
44
# Configure SP+WRR queuing on HundredGigE 1/0/1.
[Sysname] interface hundredgige 1/0/1
[Sysname-HundredGigE1/0/1] qos wrr weight
[Sysname-HundredGigE1/0/1] qos wrr 4 group sp
[Sysname-HundredGigE1/0/1] qos wrr 5 group sp
[Sysname-HundredGigE1/0/1] qos wrr 6 group sp
[Sysname-HundredGigE1/0/1] qos wrr 7 group sp
[Sysname-HundredGigE1/0/1] qos wrr 0 group 1 weight 1
[Sysname-HundredGigE1/0/1] qos wrr 1 group 1 weight 2
[Sysname-HundredGigE1/0/1] qos wrr 2 group 1 weight 1
[Sysname-HundredGigE1/0/1] qos wrr 3 group 1 weight 3
Configuring SP+WFQ queuing
Configuration procedure
To configure SP+WFQ queuing:
Step
1. Enter system view.
2. Enter interface view.
Command system-view
interface interface-type
interface-number
Remarks
N/A
N/A
3. Enable byte-count or packet-based WFQ queuing. qos wfq { byte-count | weight }
By default, byte-count WRR queuing is used on an interface.
4. Assign a queue to the SP group.
qos wfq queue-id group sp
By default, all queues on a
WFQ-enabled interface are in WFQ group 1.
5. Assign a queue to the
WFQ group, and configure a scheduling weight for the queue. qos
wfq queue-id group 1 { byte-count
| weight } schedule-value
By default, all queues on a
WFQ-enabled interface are in WFQ group 1 and have a scheduling value of 1.
Select byte-count or weight according to the WFQ type
(byte-count or packet-based) you have enabled.
6. (Optional.) Set the minimum guaranteed bandwidth for a queue.
Configuration example
qos bandwidth queue queue-id
min bandwidth-value
The default setting is 64 kbps.
1. Network requirements
Configure SP+WFQ queuing on HundredGigE 1/0/1, and use packet-based WFQ.
Assign queues 4 through 7 to the SP group.
Assign queues 0 through 3 to WFQ group 1, with their weights as 1, 2, 1, and 3, respectively.
Set the minimum guaranteed bandwidth to 128 Mbps for each of the four WFQ queues.
2. Configuration procedure
# Enter system view.
<Sysname> system-view
45
# Configure SP+WFQ queuing on HundredGigE 1/0/1.
[Sysname] interface hundredgige 1/0/1
[Sysname-HundredGigE1/0/1] qos wfq weight
[Sysname-HundredGigE1/0/1] qos wfq 4 group sp
[Sysname-HundredGigE1/0/1] qos wfq 5 group sp
[Sysname-HundredGigE1/0/1] qos wfq 6 group sp
[Sysname-HundredGigE1/0/1] qos wfq 7 group sp
[Sysname-HundredGigE1/0/1] qos wfq 0 group 1 weight 1
[Sysname-HundredGigE1/0/1] qos bandwidth queue 4 min 128000
[Sysname-HundredGigE1/0/1] qos wfq 1 group 1 weight 2
[Sysname-HundredGigE1/0/1] qos bandwidth queue 5 min 128000
[Sysname-HundredGigE1/0/1] qos wfq 2 group 1 weight 1
[Sysname-HundredGigE1/0/1] qos bandwidth queue 6 min 128000
[Sysname-HundredGigE1/0/1] qos wfq 3 group 1 weight 3
[Sysname-HundredGigE1/0/1] qos bandwidth queue 7 min 128000
Displaying and maintaining congestion management
Execute display commands in any view and reset commands in user view.
Task
Display SP queuing configuration.
Display WRR queuing configuration.
Display WFQ queuing configuration.
Display queue-based outgoing traffic statistics for interfaces.
Clear interface statistics.
Command display qos queue sp interface [ interface-type interface-number ] display qos queue wrr interface [ interface-type interface-number ] display qos queue wfq interface [ interface-type interface-number ] display qos queue-statistics interface [ interface-type interface-number ] outbound reset counters interface [ interface-type
[ interface-number | interface-number.subnumber
] ]
46
Configuring congestion avoidance
Overview
Avoiding congestion before it occurs is a proactive approach to improving network performance. As a flow control mechanism, congestion avoidance:
•
Actively monitors network resources (such as queues and memory buffers).
•
Drops packets when congestion is expected to occur or deteriorate.
When dropping packets from a source end, congestion avoidance cooperates with the flow control mechanism at the source end to regulate the network traffic size. The combination of the local packet drop policy and the source-end flow control mechanism implements the following functions:
•
Maximizes throughput and network use efficiency.
•
Minimizes packet loss and delay.
Tail drop
Congestion management techniques drop all packets that are arriving at a full queue. This tail drop mechanism results in global TCP synchronization. If packets from multiple TCP connections are dropped, these TCP connections go into the state of congestion avoidance and slow start to reduce traffic. However, traffic peak occurs later. Consequently, the network traffic jitters all the time.
RED and WRED
You can use Random Early Detection (RED) or Weighted Random Early Detection (WRED) to avoid global TCP synchronization.
Both RED and WRED avoid global TCP synchronization by randomly dropping packets. When the sending rates of some TCP sessions slow down after their packets are dropped, other TCP sessions remain at high sending rates. Link bandwidth is efficiently used, because TCP sessions at high sending rates always exist.
The RED or WRED algorithm sets an upper threshold and lower threshold for each queue, and processes the packets in a queue as follows:
•
When the queue size is shorter than the lower threshold, no packet is dropped.
•
When the queue size reaches the upper threshold, all subsequent packets are dropped.
•
When the queue size is between the lower threshold and the upper threshold, the received packets are dropped at random. The drop probability in a queue increases along with the queue size under the maximum drop probability.
If the current queue size is compared with the upper threshold and lower threshold to determine the drop policy, burst traffic is not fairly treated. To solve this problem, WRED compares the average queue size with the upper threshold and lower threshold to determine the drop probability.
The average queue size reflects the queue size change trend but is not sensitive to burst queue size changes, and burst traffic can be fairly treated.
When WFQ queuing is used, you can set the following parameters for packets with different precedence values to provide differentiated drop policies:
•
Exponent for average queue size calculation.
•
Upper threshold.
•
Lower threshold.
47
•
Drop probability.
Relationship between WRED and queuing mechanisms
Figure 16 Relationship between WRED and queuing mechanisms
WRED drop
Queue 1 weight 1
Packets to be sent through this interface
Queue 2 weight 2
Packets sent
Classify
……
Interface
……
Queue N-1 weight N-1
Schedule Sending queue
Queue N weight N
Packets dropped
Through combining WRED with WFQ, the flow-based WRED can be realized. Each flow has its own queue after classification.
•
A flow with a smaller queue size has a lower packet drop probability.
•
A flow with a larger queue size has a higher packet drop probability.
In this way, the benefits of the flow with a smaller queue size are protected.
ECN
By dropping packets, WRED alleviates the influence of congestion on the network. However, the network resources for transmitting packets from the sender to the device which drops the packets are wasted. When congestion occurs, it is a better idea to perform the following actions:
•
Inform the sender of the congestion status.
•
Have the sender proactively slow down the packet sending rate or decrease the window size of packets.
This better utilizes the network resources.
RFC 2482 defined an end-to-end congestion notification mechanism named Explicit Congestion
Notification (ECN). ECN uses the DS field in the IP header to mark the congestion status along the packet transmission path. An ECN-capable terminal can determine whether congestion occurs on the transmission path according to the packet contents. Then, it adjusts the packet sending speed to avoid deteriorating congestion. ECN defines the last two bits (ECN field) in the DS field of the IP header as follows:
•
Bit 6 indicates whether the sending terminal device supports ECN, and is called the
ECN-Capable Transport (ECT) bit.
•
Bit 7 indicates whether the packet has experienced congestion along the transmission path, and is called the Congestion Experienced (CE) bit.
For more information about the DS field, see " Appendixes ."
48
In actual applications, the following packets are considered as packets that an ECN-capable endpoint transmits:
•
Packets with ECT set to 1 and CE set to 0.
•
Packets with ECT set to 0 and CE set to 1.
After you enable ECN on a device, congestion management processes packets as follows:
•
When the average queue size is below the lower threshold, no packet is dropped, and the ECN fields of packets are not identified or marked.
•
When the average queue size is between the lower threshold and the upper threshold, the device performs the following operations: a. Picks out packets to be dropped according to the drop probability. b. Examines the ECN fields of these packets and determines whether to drop these packets.
If the ECN field shows that the packet is sent out of ECN-capable terminal, the device performs the following operations:
−
Sets both the ECT bit and the CE bit to 1.
−
Forwards the packet.
If both the ECT bit and the CE bit are 1 in the packet, the device forwards the packet without modifying the ECN field. The combination of ECT bit 1 and CE bit 1 indicates that the packet has experienced congestion along the transmission path.
If both the ECT bit and the CE bit is 0 in the packet, the device drops the packet.
•
When the average queue size exceeds the upper threshold, the device drops the packet, regardless of whether the packet is sent from an ECN-capable terminal.
The switch supports enabling ECN on a per-queue basis.
WRED parameters
The switch supports queue-based WRED tables. You can configure separate drop parameters for different queues. When congestion occurs, packets of a queue are randomly dropped based on the drop parameters of the queue.
Determine the following parameters before configuring WRED:
•
Upper threshold and lower threshold —When the average queue size is smaller than the lower threshold, packets are not dropped. When the average queue size is between the lower threshold and the upper threshold, the packets are dropped at random. The longer the queue, the higher the drop probability. When the average queue size exceeds the upper threshold, subsequent packets are dropped.
•
Drop precedence —A parameter used for packet drop. The value 0 corresponds to green packets, the value 1 corresponds to yellow packets, and the value 2 corresponds to red packets. Red packets are dropped preferentially.
•
Exponent for average queue size calculation —The greater the exponent, the less sensitive the average queue size is to real-time queue size changes. The formula for calculating the average queue size is:
Average queue size = ( previous average queue size x (1 – 2
–n
) ) + (current queue size x 2
–n
), where n is the exponent.
•
Drop probability —The drop probability is expressed in percentage. The greater the percentage value, the greater the drop probability.
49
Configuring and applying a queue-based WRED table
By using a queue-based WRED table, WRED randomly drops packets during congestion based on the queues that hold packets.
Both Layer 2 and Layer 3 Ethernet interfaces support WRED tables. The term "interface" in this section collectively refers to these two types of interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN
Switching Configuration Guide ).
To configure and apply a queue-based WRED table:
Step
1. Enter system view.
2. Create a
WRED table and enter its view.
3. (Optional.) Set the WRED exponent for average queue size calculation.
Command system-view
qos wred queue table table-name queue queue-id weighting-constant exponent
4. (Optional.)
Configure the other WRED parameters.
5. (Optional.)
Enable ECN for a queue.
6. Return to system view.
7. Enter interface view.
Remarks
N/A
N/A
The default setting is 9. queue queue-id
[ drop-level drop-level ] low-limit low-limit high-limit high-limit
[ discard-probability discard-prob ]
By default, the lower limit is 100, the upper limit is
1000, and the drop probability is
10%. queue queue-id ecn
By default, ECN is disabled for a queue. quit interface interface-type interface-number
N/A
N/A
8. Apply the
WRED table to the interface. qos wred apply [ table-name ]
By default, no
WRED table is applied to an interface, and the tail drop is used on an interface.
Configuration example
Network requirements
Apply a WRED table to HundredGigE 1/0/2, so that the packets are dropped as follows when congestion occurs:
50
•
For the interface to preferentially forward higher-priority traffic, set a lower drop probability for a queue with a greater queue number. Set different drop parameters for queue 0, queue 3, and queue 7.
•
Drop packets according to their colors.
In queue 0, set the drop probability to 25%, 50%, and 75% for green, yellow, and red packets, respectively.
In queue 3, set the drop probability to 5%, 10%, and 25% for green, yellow, and red packets, respectively.
In queue 7, set the drop probability to 1%, 5%, and 10% for green, yellow, and red packets, respectively.
•
Enable ECN for queue 7.
Configuration procedure
# Configure a queue-based WRED table, and set different drop parameters for packets with different drop levels in different queues.
<Sysname> system-view
[Sysname] qos wred queue table queue-table1
[Sysname-wred-table-queue-table1] queue 0 drop-level 0 low-limit 128 high-limit 512 discard-probability 25
[Sysname-wred-table-queue-table1] queue 0 drop-level 1 low-limit 128 high-limit 512 discard-probability 50
[Sysname-wred-table-queue-table1] queue 0 drop-level 2 low-limit 128 high-limit 512 discard-probability 75
[Sysname-wred-table-queue-table1] queue 3 drop-level 0 low-limit 256 high-limit 640 discard-probability 5
[Sysname-wred-table-queue-table1] queue 3 drop-level 1 low-limit 256 high-limit 640 discard-probability 10
[Sysname-wred-table-queue-table1] queue 3 drop-level 2 low-limit 256 high-limit 640 discard-probability 25
[Sysname-wred-table-queue-table1] queue 7 drop-level 0 low-limit 512 high-limit 1024 discard-probability 1
[Sysname-wred-table-queue-table1] queue 7 drop-level 1 low-limit 512 high-limit 1024 discard-probability 5
[Sysname-wred-table-queue-table1] queue 7 drop-level 2 low-limit 512 high-limit 1024 discard-probability 10
[Sysname-wred-table-queue-table1] queue 7 ecn
[Sysname-wred-table-queue-table1] quit
# Apply the queue-based WRED table to HundredGigE 1/0/2.
[Sysname] interface hundredgige 1/0/2
[Sysname-HundredGigE1/0/2] qos wred apply queue-table1
[Sysname-HundredGigE1/0/2] quit
Displaying and maintaining WRED
Execute display commands in any view.
Task Command
Display WRED configuration and statistics for display qos wred interface [ interface-type
51
Task an interface.
Display the configuration of a WRED table or all WRED tables.
Command interface-number display qos wred table [ name table-name ]
[ slot slot-number ]
52
Configuring traffic filtering
You can filter in or filter out traffic of a class by associating the class with a traffic filtering action. For example, you can filter packets sourced from an IP address according to network status.
Configuration procedure
To configure traffic filtering:
Remark s
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name [ operator { and | or } ]
3. Configu re a match criterion
.
if-match match-criteria
4. Return to system view.
5. Create a traffic behavio r and enter traffic behavio r view. quit
traffic behavior behavior-name
N/A
By default, no traffic classes exist.
By default, no match criterion is configure d.
N/A
By default, no traffic behaviors exist.
6. Configu re the traffic filtering action. filter { deny | permit }
By default, no traffic filtering action is configure d.
7. Return to system view.
8. Create a QoS policy and quit qos policy policy-name
N/A
By default, no
QoS policies
53
Step enter
QoS policy view.
9. Associa te the traffic class with the traffic behavio r in the
QoS policy.
10. Return to system view.
Command classifier classifier-name behavior behavior-name [ insert-before before-clas sifier-name ] quit
Remark s exist.
By default, a traffic class is not associate d with a traffic behavior.
N/A
11. Apply the QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy globally
Applying the QoS policy to a control plane
Applying the QoS policy to a user profile
Choose one of the applicatio n destinatio ns as needed.
By default, no
QoS policy is applied.
12. (Option al.)
Display the traffic filtering configur ation. display traffic behavior user-defined [ behavior-name ]
Available in any view.
Configuration example
Network requirements
with a source port number other than 21.
Figure 17 Network diagram
Host
Device
HGE1/0/1
54
Configuration procedure
# Create advanced ACL 3000, and configure a rule to match packets whose source port number is not 21.
<Device> system-view
[Device] acl advanced 3000
[Device-acl-ipv4-adv-3000] rule 0 permit tcp source-port neq 21
[Device-acl-ipv4-adv-3000] quit
# Create a traffic class named classifier_1 , and use ACL 3000 as the match criterion in the traffic class.
[Device] traffic classifier classifier_1
[Device-classifier-classifier_1] if-match acl 3000
[Device-classifier-classifier_1] quit
# Create a traffic behavior named behavior_1 , and configure the traffic filtering action to drop packets.
[Device] traffic behavior behavior_1
[Device-behavior-behavior_1] filter deny
[Device-behavior-behavior_1] quit
# Create a QoS policy named policy , and associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.
[Device] qos policy policy
[Device-qospolicy-policy] classifier classifier_1 behavior behavior_1
[Device-qospolicy-policy] quit
# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] qos apply policy policy inbound
55
Configuring priority marking
Priority marking sets the priority fields or flag bits of packets to modify the priority of packets. For example, you can use priority marking to set IP precedence or DSCP for a class of IP packets to control the forwarding of these packets.
To configure priority marking to set the priority fields or flag bits for a class of packets, perform the following tasks:
1. Configure a traffic behavior with a priority marking action.
2. Associate the traffic class with the traffic behavior.
Configuration procedure
To configure priority marking:
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name [ operator { and | or } ]
Remarks
N/A
By default, no traffic classes exist.
3. Configu re a match criterio n.
if-match match-criteria
By default, no match criterion is configured.
For more information about the if-match command, see ACL and
QoS
Command
Reference .
4. Return to system view.
5. Create a traffic behavi or and enter traffic behavi or view.
6. Configu re a quit
traffic behavior behavior-name
•
Set the DSCP value for packets: remark [ green | red | yellow ] dscp dscp-value
56
N/A
By default, no traffic behaviors exist.
Use one of the
Step priority markin g action.
Command
•
Set the 802.1p priority for packets or configure the inner-to-outer tag priority copying feature: remark [ green | red | yellow ] dot1p dot1p-value remark dot1p customer-dot1p-trust
•
Set the drop priority for packets: remark drop-precedence drop-precedence-value
•
Set the IP precedence for packets: remark ip-precedence ip-precedence-value
•
Set the local precedence for packets: remark [ green | red | yellow ] local-precedence local-precedence-value
•
Set the local QoS ID for packets:
remark qos-local-id local-id-value
•
Set the CVLAN for packets: remark customer-vlan-id vlan-id
•
Set the SVLAN for packets: remark service-vlan-id vlan-id
7. Return to system view.
8. Create a QoS policy and enter
QoS policy view.
9. Associ ate the traffic class with the traffic behavi or in the
QoS policy.
10. Return to system view. quit qos policy policy-name classifier classifier-name behavior behavior-name [ insert-before beforeclassifier-name ] quit
Remarks commands.
By default, no priority marking action is configured.
The remark drop-precede nce command applies only to the incoming traffic.
N/A
By default, no
QoS policies exist.
By default, a traffic class is not associated with a traffic behavior.
N/A
11. Apply the
QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy globally
Applying the QoS policy to a control plane
Applying the QoS policy to a user profile
Choose one of the application destinations as needed.
By default, no
QoS policy is applied.
12. (Option al.)
Display the priority markin g display traffic behavior user-defined [ behavior-name ]
Available in any view.
57
Step configu ration.
Command
Configuration example
Remarks
Network requirements
As shown in Figure 18 , configure priority marking on the device to meet the following requirements:
Traffic source
Host A, B
Host A, B
Destination
Data server
Mail server
Host A, B
Figure 18 Network diagram
File server
Processing priority
High
Medium
Low
Internet
Host A Data server
192.168.0.1/24
HGE1/0/1 HGE1/0/2 Mail server
192.168.0.2/24
Host B
Device
File server
192.168.0.3/24
Configuration procedure
# Create advanced ACL 3000, and configure a rule to match packets with destination IP address
192.168.0.1.
<Device> system-view
[Device] acl advanced 3000
[Device-acl-ipv4-adv-3000] rule permit ip destination 192.168.0.1 0
[Device-acl-ipv4-adv-3000] quit
# Create advanced ACL 3001, and configure a rule to match packets with destination IP address
192.168.0.2.
[Device] acl advanced 3001
[Device-acl-ipv4-adv-3001] rule permit ip destination 192.168.0.2 0
[Device-acl-ipv4-adv-3001] quit
# Create advanced ACL 3002, and configure a rule to match packets with destination IP address
192.168.0.3.
[Device] acl advanced 3002
[Device-acl-ipv4-adv-3002] rule permit ip destination 192.168.0.3 0
58
[Device-acl-ipv4-adv-3002] quit
# Create a traffic class named classifier_dbserver , and use ACL 3000 as the match criterion in the traffic class.
[Device] traffic classifier classifier_dbserver
[Device-classifier-classifier_dbserver] if-match acl 3000
[Device-classifier-classifier_dbserver] quit
# Create a traffic class named classifier_mserver , and use ACL 3001 as the match criterion in the traffic class.
[Device] traffic classifier classifier_mserver
[Device-classifier-classifier_mserver] if-match acl 3001
[Device-classifier-classifier_mserver] quit
# Create a traffic class named classifier_fserver , and use ACL 3002 as the match criterion in the traffic class.
[Device] traffic classifier classifier_fserver
[Device-classifier-classifier_fserver] if-match acl 3002
[Device-classifier-classifier_fserver] quit
# Create a traffic behavior named behavior_dbserver , and configure the action of setting the local precedence value to 4.
[Device] traffic behavior behavior_dbserver
[Device-behavior-behavior_dbserver] remark local-precedence 4
[Device-behavior-behavior_dbserver] quit
# Create a traffic behavior named behavior_mserver , and configure the action of setting the local precedence value to 3.
[Device] traffic behavior behavior_mserver
[Device-behavior-behavior_mserver] remark local-precedence 3
[Device-behavior-behavior_mserver] quit
# Create a traffic behavior named behavior_fserver , and configure the action of setting the local precedence value to 2.
[Device] traffic behavior behavior_fserver
[Device-behavior-behavior_fserver] remark local-precedence 2
[Device-behavior-behavior_fserver] quit
# Create a QoS policy named policy_server , and associate traffic classes with traffic behaviors in the QoS policy.
[Device] qos policy policy_server
[Device-qospolicy-policy_server] classifier classifier_dbserver behavior behavior_dbserver
[Device-qospolicy-policy_server] classifier classifier_mserver behavior behavior_mserver
[Device-qospolicy-policy_server] classifier classifier_fserver behavior behavior_fserver
[Device-qospolicy-policy_server] quit
# Apply QoS policy policy_server to the incoming traffic of HundredGigE 1/0/1.
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] qos apply policy policy_server inbound
[Device-HundredGigE1/0/1] quit
59
Configuring nesting
Nesting adds a VLAN tag to the matching packets to allow the VLAN-tagged packets to pass through the corresponding VLAN. For example, you can add an outer VLAN tag to packets from a customer network to a service provider network. This allows the packets to pass through the service provider network by carrying a VLAN tag assigned by the service provider.
Configuration procedure
To configure nesting:
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name [ operator { and | or } ]
Remarks
N/A
By default, no traffic classes exist.
3. Configu re a match criterio n.
if-match match-criteria
By default, no match criterion is configured for a traffic class.
For more informatio n about the match criteria, see the if-mat ch command in ACL and QoS
Command
Reference
.
4. Return to system view.
5. Create a traffic behavi or and enter traffic behavi or view. quit
traffic behavior behavior-name
6. Configu nest top-most vlan vlan-id
N/A
By default, no traffic behaviors exist.
By default,
60
Step re a
VLAN tag adding action.
Command Remarks no VLAN tag adding action is configured for a traffic behavior.
7. Return to system view.
8. Create a QoS policy and enter
QoS policy view.
9. Associ ate the traffic class with the traffic behavi or in the
QoS policy.
10. Return to system view. quit qos policy policy-name classifier classifier-name behavior behavior-name [ insert-before before-clas sifier-name ] quit
N/A
By default, no QoS policies exist.
By default, a traffic class is not associated with a traffic behavior.
N/A
11. Apply the
QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy globally
Applying the QoS policy to a control plane
Choose one of the application destinatio ns as needed.
By default, no QoS policy is applied.
Configuration example
Network requirements
•
Site 1 and Site 2 in VPN A are two branches of a company. They use VLAN 5 to transmit traffic.
•
Because Site 1 and Site 2 are located in different areas, the two sites use the VPN access service of a service provider. The service provider assigns VLAN 100 to the two sites.
Configure nesting, so that the two branches can communicate through the service provider network.
61
Figure 19 Network diagram
PE 1
HGE1/0/1
Public network
VLAN 100 VLAN 5 Data
IP network
VLAN 100 VLAN 5 Data
PE 2
HGE1/0/1
VLAN 5 Data VLAN 5 Data
CE 1
VLAN 5
VPN A
Site 1
VPN A
Site 2
CE 2
Configuration procedure
Configuring PE 1
# Create a traffic class named test to match traffic with VLAN ID 5.
<PE1> system-view
[PE1] traffic classifier test
[PE1-classifier-test] if-match service-vlan-id 5
[PE1-classifier-test] quit
# Configure an action to add outer VLAN tag 100 in traffic behavior test .
[PE1] traffic behavior test
[PE1-behavior-test] nest top-most vlan 100
[PE1-behavior-test] quit
# Create a QoS policy named test , and associate class test with behavior test in the QoS policy.
[PE1] qos policy test
[PE1-qospolicy-test] classifier test behavior test
[PE1-qospolicy-test] quit
# Configure the downlink port (HundredGigE 1/0/1) as a hybrid port, and assign the port to VLAN 100 as an untagged member.
[PE1] interface hundredgige 1/0/1
[PE1-HundredGigE1/0/1] port link-type hybrid
[PE1-HundredGigE1/0/1] port hybrid vlan 100 untagged
# Apply QoS policy test to the incoming traffic of HundredGigE 1/0/1.
[PE1-HundredGigE1/0/1] qos apply policy test inbound
[PE1-HundredGigE1/0/1] quit
# Configure the uplink port (HundredGigE 1/0/2) as a trunk port, and assign it to VLAN 100.
[PE1] interface hundredgige 1/0/2
[PE1-HundredGigE1/0/2] port link-type trunk
[PE1-HundredGigE1/0/2] port trunk permit vlan 100
[PE1-HundredGigE1/0/2] quit
62
Configuring PE 2
Configure PE 2 in the same way PE 1 is configured.
63
Configuring traffic redirecting
Traffic redirecting redirects packets matching the specified match criteria to a location for processing.
You can redirect packets to an interface or the CPU.
Configuration procedure
To configure traffic redirecting:
Command Step
1. Enter system view.
2. Create a traffic class and enter traffic class view. system-view traffic classifier classifier-name [ operator { and | or } ]
Remarks
N/A
By default, no traffic classes exist.
3. Configu re a match criterion
.
if-match match-criteria
By default, no match criterion is configured for a traffic class.
For more informatio n about the match criteria, see the if-mat ch command in ACL and
QoS
Command
Reference .
4. Return to system view.
5. Create a traffic behavio r and enter traffic behavio r view.
6. Configu re a traffic redirecti quit
traffic behavior behavior-name redirect { cpu | interface interface-type interface-number }
64
N/A
By default, no traffic behaviors exist.
By default, no traffic redirecting action is
Step ng action.
Command
7. Return to system view.
8. Create a QoS policy and enter
QoS policy view.
9. Associa te the traffic class with the traffic behavio r in the
QoS quit qos policy policy-name classifier classifier-name behavior behavior-name [ insert-before before-cla ssifier-name ]
N/A
By default, no QoS policies exist.
By default, a traffic class is not associated with a traffic behavior.
Remarks configured for a traffic behavior.
If you execute this command multiple times, the most recent configurati on takes effect.
For traffic redirecting to an
Ethernet interface on an interface card, the switch does not display the redirecting action after the interface card is removed.
After the interface card is reinserted, the switch can display the redirecting action.
65
Step policy.
10. Return to system view.
Command quit
Remarks
N/A
11. Apply the QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy globally
Applying the QoS policy to a control plane
Applying the QoS policy to a user profile
12. (Option al.)
Display traffic redirecti ng configur ation. display traffic behavior user-defined [ behavior-name ]
Available in any view.
Configuration example
Network requirements
•
Device A is connected to Device B through two links. Device A and Device B are each connected to other devices.
•
HundredGigE 1/0/2 of Device A and HundredGigE 1/0/2 of Device B belong to VLAN 200.
•
HundredGigE 1/0/3 of Device A and HundredGigE 1/0/3 of Device B belong to VLAN 201.
•
On Device A, the IP address of VLAN-interface 200 is 200.1.1.1/24, and that of VLAN-interface
201 is 201.1.1.1/24.
•
On Device B, the IP address of VLAN-interface 200 is 200.1.1.2/24, and that of VLAN-interface
201 is 201.1.1.2/24.
Configure the actions of redirecting traffic to an interface to meet the following requirements:
•
Packets with source IP address 2.1.1.1 received on HundredGigE 1/0/1 of Device A are forwarded to HundredGigE 1/0/2.
Choose one of the application destination s as needed.
By default, no QoS policy is applied.
The traffic redirecting action takes effect only when the
QoS policy is applied to the inbound direction.
66
•
Packets with source IP address 2.1.1.2 received on HundredGigE 1/0/1 of Device A are forwarded to HundredGigE 1/0/3.
•
Other packets received on HundredGigE 1/0/1 of Device A are forwarded according to the routing table.
Figure 20 Network diagram
HGE1/0/1
Device A
HGE1/0/2
VLAN 200
Vlan-int200
200.1.1.1/24
HGE1/0/2
VLAN 200
Vlan-int200
200.1.1.2/24
Device B
HGE1/0/1
HGE1/0/3
VLAN 201
Vlan-int201
201.1.1.1/24
HGE1/0/3
VLAN 201
Vlan-int201
201.1.1.2/24
Configuration procedure
# Create basic ACL 2000, and configure a rule to match packets with source IP address 2.1.1.1.
<DeviceA> system-view
[DeviceA] acl basic 2000
[DeviceA-acl-ipv4-basic-2000] rule permit source 2.1.1.1 0
[DeviceA-acl-ipv4-basic-2000] quit
# Create basic ACL 2001, and configure a rule to match packets with source IP address 2.1.1.2.
[DeviceA] acl basic 2001
[DeviceA-acl-ipv4-basic-2001] rule permit source 2.1.1.2 0
[DeviceA-acl-ipv4-basic-2001] quit
# Create a traffic class named classifier_1 , and use ACL 2000 as the match criterion in the traffic class.
[DeviceA] traffic classifier classifier_1
[DeviceA-classifier-classifier_1] if-match acl 2000
[DeviceA-classifier-classifier_1] quit
# Create a traffic class named classifier_2 , and use ACL 2001 as the match criterion in the traffic class.
[DeviceA] traffic classifier classifier_2
[DeviceA-classifier-classifier_2] if-match acl 2001
[DeviceA-classifier-classifier_2] quit
# Create a traffic behavior named behavior_1 , and configure the action of redirecting traffic to
HundredGigE 1/0/2.
[DeviceA] traffic behavior behavior_1
[DeviceA-behavior-behavior_1] redirect interface hundredgige 1/0/2
[DeviceA-behavior-behavior_1] quit
# Create a traffic behavior named behavior_2 , and configure the action of redirecting traffic to
HundredGigE 1/0/3.
[DeviceA] traffic behavior behavior_2
[DeviceA-behavior-behavior_2] redirect interface hundredgige 1/0/3
[DeviceA-behavior-behavior_2] quit
# Create a QoS policy named policy .
[DeviceA] qos policy policy
# Associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.
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[DeviceA-qospolicy-policy] classifier classifier_1 behavior behavior_1
# Associate traffic class classifier_2 with traffic behavior behavior_2 in the QoS policy.
[DeviceA-qospolicy-policy] classifier classifier_2 behavior behavior_2
[DeviceA-qospolicy-policy] quit
# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.
[DeviceA] interface hundredgige 1/0/1
[DeviceA-HundredGigE1/0/1] qos apply policy policy inbound
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Configuring global CAR
Overview
Global committed access rate (CAR) is an approach to policing traffic flows globally. It adds flexibility to common CAR where traffic policing is performed only on a per-traffic class or per-interface basis.
In this approach, CAR actions are created in system view and each can be used to police multiple traffic flows as a whole.
Global CAR provides the following CAR actions: aggregate CAR and hierarchical CAR. Only aggregate CAR is supported in the current software version.
Aggregate CAR
An aggregate CAR action is created globally. It can be directly applied to interfaces or used in the traffic behaviors associated with different traffic classes to police multiple traffic flows as a whole.
The total rate of the traffic flows must conform to the traffic policing specifications set in the aggregate CAR action.
Hierarchical CAR
A hierarchical CAR action is created globally. It must be used in conjunction with a common CAR or aggregate CAR action. With a hierarchical CAR action, you can limit the total traffic of multiple traffic classes.
A hierarchical CAR action can be used in the common or aggregate CAR action for a traffic class in either AND mode or OR mode.
•
In AND mode, the rate of the traffic class is strictly limited under the common or aggregate CAR.
This mode applies to flows that must be strictly rate limited.
•
In OR mode, the traffic class can use idle bandwidth of other traffic classes associated with the hierarchical CAR. This mode applies to high priority, bursty traffic like video.
By using the two modes appropriately, you can improve bandwidth efficiency.
For example, suppose two flows exist: a low priority data flow and a high priority, bursty video flow.
Their total traffic rate cannot exceed 4096 kbps and the video flow must be assured of at least 2048 kbps bandwidth. You can perform the following tasks:
•
Configure common CAR actions to set the traffic rate to 2048 kbps for the two flows.
•
Configure a hierarchical CAR action to limit their total traffic rate to 4096 kbps.
•
Use the action in AND mode in the common CAR action for the data flow.
•
Use the action in OR mode in the common CAR action for the video flow.
The video flow is assured of 2048 kbps bandwidth and can use idle bandwidth of the data flow.
In a bandwidth oversubscription scenario, the uplink port bandwidth is lower than the total downlink port traffic rate. You can use hierarchical CAR to meet the following requirements:
•
Limit the total rate of downlink port traffic.
•
Allow each downlink port to forward traffic at the maximum rate when the other ports are idle.
For example, you can perform the following tasks:
•
Use common CAR actions to limit the rates of Internet access flow 1 and flow 2 to both 128 kbps.
69
•
Use a hierarchical CAR action to limit their total traffic rate to 192 kbps.
•
Use the hierarchical CAR action for both flow 1 and flow 2 in AND mode.
When flow 1 is not present, flow 2 is transmitted at the maximum rate, 128 kbps. When both flows are present, the total rate of the two flows cannot exceed 192 kbps. As a result, the traffic rate of flow 2 might drop below 128 kbps.
Configuring aggregate CAR by using the MQC approach
Step
1. Enter system view.
Command system-view
Remarks
N/A
2. Configure an aggregate CAR action.
qos car car-name aggregative
cir committed-information-rate [
cbs committed-burst-size [ ebs excess-burst-size ] ]
[ green action | red action | yellow action ] *
qos car car-name aggregative
cir committed-information-rate [
cbs committed-burst-size ] pir peak-information-rate
[ ebs excess-burst-size ] [ green action | red action
| yellow action ] *
Use either command.
By default, no aggregate CAR action is configured.
3. Enter traffic behavior view. traffic behavior behavior-name N/A
4. Use the aggregate
CAR in the traffic behavior.
car name car-name
By default, no aggregate CAR action is used in a traffic behavior.
Displaying and maintaining global CAR
Execute display commands in any view and reset commands in user view.
Task
Display statistics for global CAR actions.
Clear statistics for global CAR actions.
Command display qos car name [ car-name ] reset qos car name [ car-name ]
70
Configuring class-based accounting
Class-based accounting collects statistics (in packets or bytes) on a per-traffic class basis. For example, you can define the action to collect statistics for traffic sourced from a certain IP address.
By analyzing the statistics, you can determine whether anomalies have occurred and what action to take.
Configuration procedure
To configure class-based accounting:
Step
1. Enter system view.
2. Create a traffic class and enter traffic class view.
Command system-view traffic classifier classifier-name [ operator { and | or } ]
Remarks
N/A
By default, no traffic classes exist.
3. Configu re a match criterio n.
if-match match-criteria
By default, no match criterion is configured
.
For more informatio n about the if-mat ch command, see ACL and QoS
Command
Reference
.
4. Return to system view.
5. Create a traffic behavi or and enter traffic behavi or view.
6. Configu re an accoun ting action. quit
traffic behavior behavior-name accounting { byte | packet }
N/A
By default, no traffic behaviors exist.
By default, no traffic accountin g action is configured
71
Step Command Remarks
.
7. Return to system view.
8. Create a QoS policy and enter
QoS policy view.
9. Associ ate the traffic class with the traffic behavi or in the
QoS policy.
10. Return to system view. quit qos policy policy-name classifier classifier-name behavior behavior-name [ insert-before before-clas sifier-name ] quit
N/A
By default, no QoS policies exist.
By default, a traffic class is not associated with a traffic behavior.
N/A
11. Apply the
QoS policy.
Applying the QoS policy to an interface
Applying the QoS policy to VLANs
Applying the QoS policy to a control plane
Applying the QoS policy to a user profile
Choose one of the application destinatio ns as needed.
By default, no QoS policy is applied.
12. Display traffic accoun ting configu ration.
• display qos policy control-plane slot slot-number
• display qos policy interface [ interface-type interface-number ]
[ inbound | outbound ]
• display qos vlan-policy { name policy-name | vlan [ vlan-id ] }
[ slot slot-number ] [ inbound | outbound ]
Available in any view.
Configuration example
Network requirements
As shown in Figure 21 , configure class-based accounting on HundredGigE 1/0/1 to collect statistics
for incoming traffic from 1.1.1.1/24.
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Figure 21 Network diagram
Host
1.1.1.1/24
Device
HGE1/0/1
Configuration procedure
# Create basic ACL 2000, and configure a rule to match packets with source IP address 1.1.1.1.
<Device> system-view
[Device] acl basic 2000
[Device-acl-ipv4-basic-2000] rule permit source 1.1.1.1 0
[Device-acl-ipv4-basic-2000] quit
# Create a traffic class named classifier_1 , and use ACL 2000 as the match criterion in the traffic class.
[Device] traffic classifier classifier_1
[Device-classifier-classifier_1] if-match acl 2000
[Device-classifier-classifier_1] quit
# Create a traffic behavior named behavior_1 , and configure the class-based accounting action.
[Device] traffic behavior behavior_1
[Device-behavior-behavior_1] accounting packet
[Device-behavior-behavior_1] quit
# Create a QoS policy named policy , and associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.
[Device] qos policy policy
[Device-qospolicy-policy] classifier classifier_1 behavior behavior_1
[Device-qospolicy-policy] quit
# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.
[Device] interface hundredgige 1/0/1
[Device-HundredGigE1/0/1] qos apply policy policy inbound
[Device-HundredGigE1/0/1] quit
# Display traffic statistics to verify the configuration.
[Device] display qos policy interface hundredgige 1/0/1
Interface: HundredGigE1/0/1
Direction: Inbound
Policy: policy
Classifier: classifier_1
Operator: AND
Rule(s) :
If-match acl 2000
Behavior: behavior_1
Accounting enable:
28529 (Packets)
73
74
Appendixes
Appendix A Acronym
Acronym
BE
CAR
ISP
MPLS
PE
PIR
QoS
RED
RSVP
SP
ToS
VPN
WFQ
WRED
WRR
CBS
CE
CIR
DiffServ
DSCP
EBS
ECN
FIFO
FQ
GTS
IntServ
Table 3 Appendix A Acronym
Full spelling
Best Effort
Committed Access Rate
Committed Burst Size
Congestion Experienced
Committed Information Rate
Differentiated Service
Differentiated Services Code Point
Excess Burst Size
Explicit Congestion Notification
First in First out
Fair Queuing
Generic Traffic Shaping
Integrated Service
Internet Service Provider
Multiprotocol Label Switching
Provider Edge
Peak Information Rate
Quality of Service
Random Early Detection
Resource Reservation Protocol
Strict Priority
Type of Service
Virtual Private Network
Weighted Fair Queuing
Weighted Random Early Detection
Weighted Round Robin
Appendix B Default priority maps
For the default dot1p-exp , dscp-dscp , and exp-dot1p priority maps, an input value yields a target value equal to it.
75
Table 4 Default dot1p-lp and dot1p-dp priority maps
4
5
6
2
3
Input priority value dot1p
0
1 dot1p-lp map lp
2
0
4
5
6
1
3 dot1p-dp map dp
0
0
0
0
0
0
0
7 7 0
Table 5 Default dscp-dp and dscp-dot1p priority maps
Input priority value dscp
0 to 7
8 to 15
16 to 23
24 to 31
32 to 39
40 to 47
48 to 55 dscp-dp map dp
0
0
0
0
0
0
0
56 to 63 0
Table 6 Default exp-dp priority map dscp-dot1p map
3
4
1
2
5
6
7 dot1p
0
2
3
0
1
4
5
6
7
Input priority value
EXP value
0
0
0
0
0
0
0
0 exp-dp map dp
76
Appendix C Introduction to packet precedences
IP precedence and DSCP values
Figure 22 ToS and DS fields
Bits:
IPv4 ToS
byte
0 1
Preced ence
2 3 4 5
Type of
Service
6 7
M
B
Z
Bits: 0 1 2 3 4 5 6 7
RFC 1122
RFC 1349
Must
Be
Zero
DS-Field
(for IPv4,ToS octet,and for
IPv6,Traffic
Class octet )
DSCP
Class Selector codepoints
CU
Currently
Unused
IP Type of Service (ToS)
RFC 791
Differentiated Services
Codepoint (DSCP)
RFC 2474
IP precedence from 0 to 7. According to RFC 2474, the ToS field is redefined as the differentiated services (DS) field. A DSCP value is represented by the first 6 bits (0 to 5) of the DS field and is in the range 0 to 63. The remaining 2 bits (6 and 7) are reserved.
Table 7 IP precedence
3
4
1
2
5
6
IP precedence (decimal)
0
7
Table 8 DSCP values
DSCP value (decimal)
46
10
12
14
18
20
22
26
28
IP precedence (binary)
000
001
010
011
100
101
110
111
DSCP value (binary)
101110
001010
001100
001110
010010
010100
010110
011010
011100
Description
Routine priority immediate flash flash-override critical internet network
Description ef af11 af12 af13 af21 af22 af23 af31 af32
77
DSCP value (decimal)
30
8
16
24
32
34
36
38
40
48
56
0
DSCP value (binary)
011110
100010
100100
100110
001000
010000
011000
100000
101000
110000
111000
000000
Description af33 af41 af42 af43 cs1 cs2 cs3 cs4 cs5 cs6 cs7 be (default)
802.1p priority
802.1p priority lies in the Layer 2 header. It applies to occasions where Layer 3 header analysis is not needed and QoS must be assured at Layer 2.
Figure 23 An Ethernet frame with an 802.1Q tag header
Destination
Address
Source
Address
802.1Q header
TPID TCI
Length
/Type
Data
FCS(CRC-
32)
6 bytes 6 bytes 4 bytes 2 bytes 46~1500 bytes 4 bytes
As shown in Figure 23 , the 4-byte 802.1Q tag header contains the 2-byte tag protocol identifier
(TPID) and the 2-byte tag control information (TCI). The value of the TPID is 0x8100. Figure 24
shows the format of the 802.1Q tag header. The Priority field in the 802.1Q tag header is called
802.1p priority, because its use is defined in IEEE 802.1p. Table 9 shows the values for 802.1p
priority.
Figure 24 802.1Q tag header
Byte 1 Byte 2 Byte 3 Byte 4
TPID(Tag protocol identifier) TCI(Tag control information)
1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 Priority
C
F
I
VLAN ID
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
Table 9 Description on 802.1p priority
802.1p priority (decimal)
0
802.1p priority (binary)
000
Description best-effort
78
5
6
7
2
3
4
802.1p priority (decimal)
1
802.1p priority (binary)
001
010
011
100
101
110
111
Description background spare excellent-effort controlled-load video voice network-management
EXP values
The EXP field is in MPLS labels for MPLS QoS purposes. As shown in Figure 25 , the EXP field is
3-bit long and is in the range of 0 to 7.
Figure 25 MPLS label structure
79
80
Configuring data buffers
Data buffers temporarily store packets to avoid packet loss.
The switch has an ingress buffer and an egress buffer. Figure 26 shows the structure of ingress and
egress buffers. An interface stores outgoing packets in the egress buffer when congestion occurs, and stores incoming packets in the ingress buffer when the CPU is busy.
Figure 26 Data buffer structure
Fixed area
Cell resources
Shared area
Ingress/egress buffer
Fixed area
Packet resources
Shared area
A buffer uses the following types of resources:
•
Cell resources —Store packets. The buffer uses cell resources based on packet sizes.
Suppose a cell resource provides 208 bytes. The buffer allocates one cell resource to a
128-byte packet and two cell resources to a 300-byte packet.
•
Packet resources —Store packet pointers. A packet pointer indicates where the packet is located in cell resources. The buffer uses one packet resource for each incoming or outgoing packet.
Each type of resources has a fixed area and a shared area.
•
Fixed area —Partitioned into queues, each of which is equally divided by all the interfaces on
the switch, as shown in Figure 27 . When congestion occurs, the following rules apply:
a. An interface first uses the relevant queues of the fixed area to store packets. b. When a queue is full, the interface uses the corresponding queue of the shared area. c. When the queue in the shared area is also full, the interface discards subsequent packets.
The system allocates the fixed area among queues as specified by the user. Even if a queue is not full, other queues cannot preempt its space. Similarly, the share of a queue for an interface cannot be preempted by other interfaces even if it is not full.
•
Shared area —Partitioned into queues, each of which is not equally divided by the interfaces,
as shown in Figure 27 . The system determines the actual shared-area space for each queue
according to user configuration and the number of packets actually received and sent. If a queue is not full, other queues can preempt its space.
The system puts packets received on all interfaces into a queue in the order they arrive. When the queue is full, subsequent packets are dropped.
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Figure 27 Fixed area and shared area
Shared area (configured by the buffer total-shared command)
Queue 0
Queue 1
Queue 2
Queue 3
Queue 4
Queue 5
Queue 6
Queue 7
Port 1 Port 2 Port 3 Port 4 …
Fixed area
Configuration task list
You can configure data buffers either automatically by enabling the Burst feature or manually.
If you have configured data buffers in one way, delete the configuration before using the other way.
Otherwise, the new configuration does not take effect.
Tasks at a glance
Perform one of the following tasks:
Configuring data buffers manually
Setting the maximum shared-area ratio for a queue
Setting the fixed-area ratio for a queue
Applying data buffer configuration
(Optional.)
Configuring data buffer monitoring
Enabling the Burst feature
The Burst feature enables the device to automatically allocate cell and packet resources. It is well suited to the following scenarios:
•
Broadcast or multicast traffic is intensive, resulting in bursts of traffic.
•
Traffic comes in and goes out in one of the following ways:
Enters a device from a high-speed interface and goes out of a low-speed interface.
Enters from multiple same-rate interfaces at the same time and goes out of an interface with the same rate.
To enable the Burst feature:
Step
1. Enter system view.
2. Enable the Burst feature.
Command system-view burst-mode enable
Remarks
N/A
By default, the Burst feature is disabled.
Disabling this feature might cause
82
Step Command Remarks the PFC function to be on longer in effect or to operate incorrectly. For more information about PFC, see Layer 2—LAN Switching
Configuration Guide .
Configuring data buffer monitoring
The data buffer on a switch is shared by all interfaces for buffering packets during periods of congestion.
This feature allows you to identify the interfaces that use an excessive amount of data buffer space.
Then, you can diagnose those interfaces for anomalies.
You can set a per-interface buffer usage threshold. The buffer usage threshold for a queue is the same as the per-interface threshold value. The switch automatically records buffer usage for each interface. When a queue on an interface uses more buffer space than the set threshold, the system counts one threshold violation for the queue.
To configure data buffer monitoring:
Step
1. Enter system view.
2. Set a per-interface buffer usage threshold.
Command system-view buffer usage threshold slot slot-number ratio ratio
Remarks
N/A
The default setting is 70%.
Configuring data buffers manually
CAUTION:
To avoid impact to the system, do not manually change data buffer settings to avoid impact to the system. If large buffer spaces are needed, use the Burst feature.
The switch supports configuring only cell resources.
Setting the shared-area ratio
After you set the shared-area ratio, the rest is automatically assigned to the fixed area.
To set the shared-area ratio:
Step
1. Enter system view.
2. Set the shared-area ratio.
Command system-view buffer egress [ slot slot-number ] cell total-shared ratio ratio
Remarks
N/A
The default setting is
100%.
Setting the maximum shared-area ratio for a queue
By default, all queues have an equal share of the shared area. This task allows you to change the maximum shared-area ratio for a queue. The other queues use the default setting.
83
The actual maximum shared-area space for each queue is determined by the chip based on your configuration and the number of packets to be received and sent.
To set the maximum shared-area ratio for a queue:
Step
1. Enter system view.
2. Set the maximum shared-area ratio for a queue.
Command system-view
Remarks
N/A buffer egress [ slot slot-number ] cell
queue queue-id shared ratio ratio
The default setting is 20%.
Setting the fixed-area ratio for a queue
By default, all queues have an equal share of the fixed area. This task allows you to change the fixed-area ratio for a queue. The other queues equally share the remaining part.
The fixed-area space for a queue cannot be used by other queues. Therefore, it is also called the minimum guaranteed buffer for the queue. The sum of fixed-area ratios configured for all queues cannot exceed the total fixed-area ratio. Otherwise, the configuration fails.
To set the fixed-area ratio for a queue:
Step
1. Enter system view.
2. Set the fixed-area ratio for a queue.
Command system-view buffer egress [ slot slot-number ] cell
queue queue-id guaranteed ratio ratio
Remarks
N/A
The default setting is
13%.
Applying data buffer configuration
Perform this task to apply the data buffer configuration.
You cannot directly modify the applied configuration. To modify the configuration, you must cancel the application, reconfigure data buffers, and reapply the configuration.
To apply data buffer configuration:
Step
1. Enter system view.
Command system-view
2. Apply data buffer configuration. buffer apply
Remarks
N/A
This command might cause the
PFC function to be on longer in effect or to operate incorrectly. For more information about PFC, see Layer 2—LAN Switching
Configuration Guide .
Displaying and maintaining data buffers
Execute display commands in any view.
Task
Display buffer size settings.
Command display buffer [ slot slot-number ] [ queue [ queue-id ] ]
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Task
Display data buffer usage.
Display buffer usage statistics for interfaces.
Command display buffer usage [ slot slot-number ] display buffer usage interface
[ interface-type [ interface-number ] ]
Burst configuration example
Network requirements
As shown in Figure 28 , a server connects to the switch through a 1000 Mbps Ethernet interface. The
server sends high-volume broadcast or multicast traffic to the hosts irregularly. Each host connects to the switch through a 100 Mbps network adapter.
Configure the switch to process high-volume traffic from the server to guarantee that packets can reach the hosts.
Figure 28 Network diagram
Server
Switch
1000M
100M
100M
100M
100M
……
Host A Host B
Configuration procedure
# Enter system view.
<Switch> system-view
# Enable the Burst feature.
[Switch] burst-mode enable
Host M Host N
85
Configuring time ranges
You can implement a service based on the time of the day by applying a time range to it. A time-based service takes effect only in time periods specified by the time range. For example, you can implement time-based ACL rules by applying a time range to them. If a time range does not exist, the service based on the time range does not take effect.
The following basic types of time ranges are available:
•
Periodic time range —Recurs periodically on a day or days of the week.
•
Absolute time range —Represents only a period of time and does not recur.
A time range is uniquely identified by the time range name. You can create a maximum of 1024 time ranges, each with a maximum of 32 periodic statements and 12 absolute statements. The active period of a time range is calculated as follows:
1. Combining all periodic statements.
2. Combining all absolute statements.
3. Taking the intersection of the two statement sets as the active period of the time range.
Configuration procedure
Step
1. Enter system view.
2. Create or edit a time range.
Command system-view
Remarks
N/A time-range time-range-name
{ start-time to end-time days [ from time1 date1 ] [ to time2 date2 ] | from time1 date1 [ to time2 date2 ] | to time2 date2 }
By default, no time ranges exist.
Displaying and maintaining time ranges
Execute the display command in any view.
Task
Display time range configuration and status.
Command display time-range { time-range-name | all }
Time range configuration example
Network requirements
As shown in Figure 29 , configure an ACL on Device A to allow Host A to access the server only
during 8:00 and 18:00 on working days from June 2015 to the end of the year.
86
Figure 29 Network diagram
Server
Host A
192.168.1.2/24
HGE1/0/1
Device A
HGE1/0/2
192.168.0.100/24
Host B
192.168.1.3/24
Configuration procedure
# Create a periodic time range during 8:00 and 18:00 on working days from June 2015 to the end of the year.
<DeviceA> system-view
[DeviceA] time-range work 8:0 to 18:0 working-day from 0:0 6/1/2015 to 24:00 12/31/2015
# Create an IPv4 basic ACL numbered 2001, and configure a rule in the ACL to permit packets only from 192.168.1.2/32 during the time range work .
[DeviceA] acl basic 2001
[DeviceA-acl-ipv4-basic-2001] rule permit source 192.168.1.2 0 time-range work
[DeviceA-acl-ipv4-basic-2001] rule deny source any time-range work
[DeviceA-acl-ipv4-basic-2001] quit
# Apply IPv4 basic ACL 2001 to filter outgoing packets on HundredGigE 1/0/2.
[DeviceA] interface hundredgige 1/0/2
[DeviceA-HundredGigE1/0/2] packet-filter 2001 outbound
[DeviceA-HundredGigE1/0/2] quit
Verifying the configuration
# Verify that the time range work is active on Device A.
[DeviceA] display time-range all
Current time is 13:58:35 6/29/2015 Friday
Time-range : work ( Active )
08:00 to 18:00 working-day
from 00:00 6/1/2015 to 00:00 1/1/2016
87
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.
Square brackets enclose a set of optional syntax choices separated by vertical bars, from which you select one or none.
Asterisk marked braces enclose a set of required syntax choices separated by vertical bars, from which you select at least one.
Asterisk marked square brackets enclose optional syntax choices separated by vertical bars, from which you select one choice, multiple choices, or none.
The argument or keyword and argument combination before the ampersand (&) sign can be entered 1 to n times.
A line that starts with a pound (#) sign is comments. #
GUI conventions
Convention
Boldface
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 .
Symbols
>
Convention
WARNING!
CAUTION:
IMPORTANT:
NOTE:
TIP:
Description
An alert that calls attention to important information that if not understood or followed can result in personal injury.
An alert that calls attention to important information that if not understood or followed can result in data loss, data corruption, or damage to hardware or software.
An alert that calls attention to essential information.
An alert that contains additional or supplementary information.
An alert that provides helpful information.
88
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.
89
Support and other resources
Accessing Hewlett Packard Enterprise Support
•
For live assistance, go to the Contact Hewlett Packard Enterprise Worldwide website: www.hpe.com/assistance
•
To access documentation and support services, go to the Hewlett Packard Enterprise Support
Center website: www.hpe.com/support/hpesc
Information to collect
•
Technical support registration number (if applicable)
•
Product name, model or version, and serial number
•
Operating system name and version
•
Firmware version
•
Error messages
•
Product-specific reports and logs
•
Add-on products or components
•
Third-party products or components
Accessing updates
•
Some software products provide a mechanism for accessing software updates through the product interface. Review your product documentation to identify the recommended software update method.
•
To download product updates, go to either of the following:
Hewlett Packard Enterprise Support Center Get connected with updates page: www.hpe.com/support/e-updates
Software Depot website: www.hpe.com/support/softwaredepot
•
To view and update your entitlements, and to link your contracts, Care Packs, and warranties with your profile, go to the Hewlett Packard Enterprise Support Center More Information on
Access to Support Materials page: www.hpe.com/support/AccessToSupportMaterials
IMPORTANT:
Access to some updates might require product entitlement when accessed through the Hewlett
Packard Enterprise Support Center. You must have an HP Passport set up with relevant entitlements.
Websites
Website
Networking websites
Link
90
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) www.hpe.com/networking/resourcefinder www.hpe.com/info/networking www.hpe.com/networking/support www.hpe.com/networking/mynetworking www.hpe.com/networking/warranty www.hpe.com/info/enterprise/docs www.hpe.com/support/hpesc ssc.hpe.com/portal/site/ssc/ www.hpe.com/assistance www.hpe.com/support/e-updates www.hpe.com/support/softwaredepot www.hpe.com/support/selfrepair www.hpe.com/info/insightremotesupport/docs
Customer self repair
Hewlett Packard Enterprise customer self repair (CSR) programs allow you to repair your product. If a CSR part needs to be replaced, it will be shipped directly to you so that you can install it at your convenience. Some parts do not qualify for CSR. Your Hewlett Packard Enterprise authorized service provider will determine whether a repair can be accomplished by CSR.
For more information about CSR, contact your local service provider or go to the CSR website: www.hpe.com/support/selfrepair
Remote support
Remote support is available with supported devices as part of your warranty, Care Pack Service, or contractual support agreement. It provides intelligent event diagnosis, and automatic, secure submission of hardware event notifications to Hewlett Packard Enterprise, which will initiate a fast and accurate resolution based on your product’s service level. Hewlett Packard Enterprise strongly recommends that you register your device for remote support.
For more information and device support details, go to the following website: www.hpe.com/info/insightremotesupport/docs
Documentation feedback
Hewlett Packard Enterprise is committed to providing documentation that meets your needs. To help us improve the documentation, send any errors, suggestions, or comments to Documentation
Feedback ( [email protected]
). When submitting your feedback, include the document title, part number, edition, and publication date located on the front cover of the document. For online help content, include the product name, product version, help edition, and publication date located on the legal notices page.
91
Index
Numerics
802
QoS packet 802.1p priority, 78
A
absolute time range (ACL), 86, 86
access control list.
ACL
configuration restrictions and guidelines, 3
IPv4 advanced configuration, 5
IPv6 advanced configuration, 7
match order, 1 naming, 1 numbering, 1
packet filtering application (interface), 9 packet filtering configuration, 9
packet filtering default action, 10
packet filtering default action
packet filtering logging+SNMP
time range configuration, 86, 86 time range display, 86
action
ACL packet filtering default action, 10
ACL packet filtering default action
advanced ACL
aggregate CAR
Appendix A
Appendix B
Appendix C
applying
ACL packet filtering (interface), 9
QoS CA queue-based WRED table, 50, 50
QoS policy (control plane), 20
area
data buffer fixed-area queue ratio, 84
data buffer shared-area queue ratio, 83
auto
data buffer shared-area ratio, 83
ACL automatic rule numbering, 2
B bandwidth
basic ACL
behavior
QoS traffic behavior definition, 18
best-effort QoS service model, 14
buffer data.
burst feature (data buffer), 85
C
CAR
aggregate CAR (MQC approach), 70
global CAR display, 70 global CAR maintain, 70
cell
92
changing
QoS priority mapping interface port priority, 25
classifying
QoS traffic class definition, 18
committed access rate.
configuring
ACL packet filtering logging+SNMP
data buffer monitoring, 83 data buffers manually, 83
QoS aggregate CAR (MQC approach), 70
QoS CA queue-based WRED table, 50, 50
QoS congestion management SP+WFQ
QoS congestion management SP+WRR
QoS priority mapping port priority, 26
QoS priority mapping table+priority
QoS priority mapping trusted port packet
congestion avoidance (QoS CA)
queue-based WRED table, 50, 50
congestion management
SP+WFQ queuing configuration, 45
SP+WRR queuing configuration, 44
congestion management (CM)
control plane
QoS policy application (control plane), 20
copying
D data buffer.
data buffer
configuration application, 84 display, 84 fixed-area queue ratio, 84
monitoring configuration, 83 shared-area queue ratio, 83 shared-area ratio, 83
default
ACL packet filtering default action, 10
ACL packet filtering default action
defining
deploying
93
detecting
device
ACL packet filtering application (interface), 9
ACL packet filtering configuration, 9
ACL packet filtering default action, 10
ACL packet filtering default action
ACL packet filtering logging+SNMP
QoS policy application (control plane), 20
QoS policy application (global), 20
QoS policy application (interface), 19
QoS policy application (user profile), 21
QoS policy application (VLAN), 20
DiffServ QoS service model, 14
displaying
drop priority (QoS priority mapping), 23
DSCP
QoS packet IP precedence and DSCP
E
ECN
enabling
ACL packet filtering default action
evaluating
QoS traffic with token bucket, 30, 30, 30
Explicit Congestion Notification.
F filtering
ACL packet filtering logging+SNMP
QoS traffic filtering configuration,
fixed area
forwarding
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
fragment
G
General Traffic Shaping.
global
QoS policy application (global), 20
global CAR
aggregate CAR (MQC approach), 70
configuration, 69 hierarchical CAR, 69
GTS
guideline
ACL configuration restrictions and guidelines, 3
H hardware
hierarchical CAR
I
IP addressing
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
QoS class-based accounting configuration,
IPv4
QoS traffic filtering configuration,
IPv6
ACL configuration (IPv4 advanced), 5
ACL configuration (IPv4 basic), 4
ACL packet filtering configuration, 9
94
ACL configuration (IPv6 advanced), 7
ACL configuration (IPv6 basic), 5
ACL packet filtering configuration, 9
L
Layer 2
limiting
local
QoS priority mapping local precedence, 23
logging
ACL packet filtering logging, 10
M maintaining
matching
mode
QoS priority mapping port priority, 26
modular QoS.
MPLS QoS
MQC
N naming
nesting
network
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
ACL packet filtering application (interface), 9
ACL packet filtering configuration, 9
ACL packet filtering default action, 10
ACL packet filtering default action
ACL packet filtering logging+SNMP
95
ACL packet fragment filtering, 3
data buffer configuration application, 84 data buffer fixed-area queue ratio, 84
data buffer shared-area queue ratio, 83 data buffer shared-area ratio, 83
QoS aggregate CAR (MQC approach), 70
QoS CA WRED queue-based table, 50, 50
QoS CA WRED-queuing relationship, 48
QoS class-based accounting configuration,
QoS congestion management SP+WFQ queuing
QoS congestion management SP+WRR queuing
QoS global CAR configuration, 69
QoS priority mapping configuration,
QoS priority mapping drop priority, 23
QoS priority mapping interface port priority, 25
QoS priority mapping port priority, 26
QoS priority mapping table+priority marking
QoS priority mapping trusted port packet
QoS priority marking configuration,
QoS traffic behavior definition, 18
QoS traffic class definition, 18
QoS traffic filtering configuration,
QoS traffic policing configuration,
QoS traffic redirection configuration,
network management
QoS priority mapping configuration, 26
time range configuration, 86, 86
non-modular QoS.
non-MQC
notifying
ACL packet filtering logging+SNMP
numbering
ACL automatic rule numbering, 2
P packet
QoS aggregate CAR (MQC approach), 70
QoS class-based accounting
QoS global CAR configuration, 69
QoS priority mapping configuration,
QoS priority mapping port priority, 26
QoS priority mapping table+priority marking
QoS priority marking configuration,
QoS traffic filtering configuration,
QoS traffic redirection configuration,
QoS trusted port packet priority, 25
packet filtering
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
ACL default action hardware-count, 10
ACL filtering application (interface), 9
ACL logging+SNMP notifications, 10
ACL packet fragment filtering, 3
parameter
periodic time range (ACL), 86, 86
policy
QoS application (control plane), 20
QoS application (interface), 19
QoS application (user profile), 21
port
QoS priority mapping interface port priority, 25
QoS trusted port packet priority, 25
precedence
QoS priority mapping configuration,
QoS priority mapping local precedence, 23
QoS priority mapping port priority, 26
QoS priority mapping table+priority marking
priority mapping.
marking.
QoS packet 802.1p priority, 78
QoS packet IP precedence and DSCP values, 77
priority mapping
96
mapping table+priority marking
trusted port packet priority, 25
priority marking
procedure
applying ACL packet filtering (interface), 9
applying data buffer configuration, 84
applying QoS CA queue-based WRED
applying QoS policy (control plane), 20 applying QoS policy (global), 20
applying QoS policy (interface), 19
applying QoS policy (user profile), 21
applying QoS policy (VLAN), 20
changing QoS priority mapping interface port
configuring ACL (IPv4 advanced), 5
configuring ACL (IPv4 basic), 4
configuring ACL (IPv6 advanced), 7
configuring ACL (IPv6 basic), 5
configuring ACL packet filtering, 9
configuring ACL packet filtering
logging+SNMP notifications, 10
configuring data buffer monitoring, 83 configuring data buffers manually, 83
configuring QoS aggregate CAR (MQC
configuring QoS CA queue-based WRED
configuring QoS class-based accounting, 71,
configuring QoS congestion management
configuring QoS congestion management
configuring QoS MQC traffic policing, 34
configuring QoS non-MQC GTS, 36
configuring QoS priority mapping, 24 configuring QoS priority mapping map, 24
configuring QoS priority mapping port priority, 26
configuring QoS priority mapping table+priority
configuring QoS priority mapping trusted port
configuring QoS priority marking,
configuring QoS rate limit, 36
configuring QoS traffic filtering,
configuring QoS traffic redirection,
configuring time range, 86, 86
defining QoS policy, 18 defining QoS traffic behavior, 18 defining QoS traffic class, 18
displaying QoS priority mapping, 26
displaying QoS rate limit, 36 displaying QoS traffic policing, 36
enabling ACL packet filtering default action
enabling data buffer burst, 82
enabling data buffer burst feature, 85
maintaining QoS global CAR, 70
setting ACL packet filtering default action, 10
setting data buffer fixed-area queue ratio, 84
setting data buffer shared-area queue ratio, 83 setting data buffer shared-area ratio, 83
Q
QoS
aggregate CAR (MQC approach), 70
Appendix B, Default priority maps, 75
Appendix C, Packet precedence, 77
class-based accounting configuration,
complicated traffic evaluation with token
97
congestion avoidance (CA) WRED
congestion avoidance (CA) WRED-queuing
relationship, 48 congestion avoidance (CA)+ECN, 48
congestion avoidance (CA)WRED display, 51
congestion management (CM)
congestion management (CM) display, 46
congestion management (CM) SP
congestion management (CM) WFQ
congestion management (CM) WRR
congestion management SP+WFQ queuing
congestion management SP+WRR queuing
data buffer configuration (manual), 83
global CAR display, 70 global CAR maintain, 70
policy application (control plane), 20 policy application (global), 20
policy application (interface), 19
policy application (user profile), 21
policy application (VLAN), 20 policy application restrictions (VLAN), 20
policy display, 22 policy maintain, 22
priority mapping configuration,
23, 24, 26 priority mapping display, 26
priority mapping drop priority, 23
priority mapping interface port priority, 25
priority mapping local precedence, 23 priority mapping map,
priority mapping port priority, 26
priority mapping table+priority marking
priority mapping trusted port packet priority, 25
priority mapping user priority, 23
priority marking configuration,
service models, 14 techniques, 14
traffic behavior definition, 18 traffic class definition, 18
traffic evaluation, 30 traffic evaluation with token bucket, 30, 30
traffic filtering configuration,
traffic policing configuration,
traffic redirection configuration,
Quality of Service.
queuing
data buffer fixed-area queue ratio, 84
data buffer shared-area queue ratio, 83
QoS CA WRED-queuing relationship, 48
98
QoS congestion management SP+WFQ
QoS congestion management SP+WRR
R random early detection.
Use RED rate limiting
QoS rate limiting configuration,
redirecting
restriction
ACL configuration restrictions and
restrictions
QoS policy application (VLAN), 20
routing
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
QoS priority mapping configuration,
QoS priority mapping port priority, 26
QoS priority mapping table+priority marking
rule
QoS traffic policing configuration,
ACL automatic rule numbering, 2
ACL config match order sort, 1
S security
ACL configuration (advanced), 5
ACL configuration (IPv4 advanced), 5
ACL configuration (IPv4 basic), 4
ACL configuration (IPv6 advanced), 7
ACL configuration (IPv6 basic), 5
ACL configuration (Layer 2), 8
service
QoS best-effort service model, 14
QoS DiffServ service model, 14
QoS global CAR configuration, 69
QoS priority marking configuration,
QoS traffic filtering configuration,
setting
ACL packet filtering default action, 10
data buffer fixed-area queue ratio, 84
data buffer shared-area queue ratio, 83 data buffer shared-area ratio, 83
shared area
data buffer queue ratio, 83 data buffer ratio, 83
SNMP
ACL packet filtering SNMP notifications, 10
sorting
ACL config match order sort, 1
SP queuing
SP+WFQ queuing
SP+WRR queuing
statistics
QoS class-based accounting configuration,
T table
QoS CA WRED queue-based table, 50, 50
TCP
time range
configuration, 86, 86 display, 86
token bucket
QoS complicated traffic evaluation, 30
QoS traffic evaluation, 30, 30
99
traffic
ACL configuration (advanced), 5
ACL configuration (Layer 2), 8
QoS aggregate CAR (MQC approach), 70
QoS CA WRED queue-based table, 50, 50
QoS CA WRED-queuing relationship, 48
QoS class-based accounting
See also under congestion management (CM)
QoS congestion management SP+WFQ
QoS congestion management SP+WRR
QoS global CAR configuration, 69
QoS policy application (control plane), 20
QoS policy application (global), 20
QoS policy application (interface), 19
QoS policy application (user profile), 21
QoS policy application (VLAN), 20
QoS priority mapping configuration, 26
QoS priority mapping interface port priority, 25
QoS priority mapping port priority, 26
QoS priority mapping table+priority marking
QoS priority mapping trusted port packet
QoS priority marking configuration,
QoS traffic behavior definition, 18
QoS traffic class definition, 18
QoS traffic classification, 15
QoS traffic filtering configuration,
QoS traffic policing configuration,
QoS traffic redirection configuration,
traffic policing
trapping
ACL packet filtering logging+SNMP
trusted
QoS trusted port packet priority, 25
type
ACL config match order sort, 1
U user
QoS priority mapping user priority, 23
user profile
QoS policy application (user profile), 21
V
VLAN
QoS policy application (VLAN), 20
W weighted random early detection.
WFQ queuing
WRED
QoS CA queue-based WRED table, 50, 50
100
QoS CA WRED-queuing relationship, 48
WRR queuing
QoS CM group-based queuing, 41
101
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