Defining a Traffic Classifier

You need to configure a traffic classifier before configuring class-based QoS. The traffic classifier can be configured based on the ACL rule, IP precedence, MAC address, protocol address, and so on.

Procedure

Define a traffic classifier based on Layer 3 or Layer 4 information
1. Run system-view
  The system view is displayed.
2. Run traffic classifier classifier-name [ operator { and | or } ]
  A traffic classifier is defined, and the traffic classifier view is displayed.
  
  If multiple matching rules are defined in a traffic classifier, you can set the logical relationship between the matching rules by specifying the parameter operator.
  - and: A packet belongs to the classifier only when it matches all the rules.
  - or: A packet belongs to the classifier when it matches any one of the rules.
3. Choose the required matching rule as required:
  - To define a matching rule to classify traffic based on the ACL number, run the if-match [ ipv6 ] acl { acl-number | name acl-name } [ precedence precedence-value ] command.
  - To define a matching rule to classify traffic based on the DSCP value, run the if-match [ ipv6 ] dscp dscp-value command.
  - To define a matching rule to classify traffic based on the IPv4 TCP flag value, run the if-match tcp syn-flag { tcpflag-value [ mask tcpflag-mask ] | bit-match { established | fin | syn | rst | psh | ack | urg | ece | cwr | ns } } command.
  - To define a matching rule to classify traffic based on the IPv6 TCP flag value, run the if-match ipv6 tcp syn-flag { tcpflag-value [ mask tcpflag-mask ] | bit-match { established | fin | syn | rst | psh | ack | urg } } command.
  - To define a matching rule to classify traffic based on the precedence of an IP packet, run the if-match [ ipv6 ] ip-precedence ip-precedence command.
  - To define a matching rule to classify traffic based on the MPLS EXP value, run the if-match mpls-exp exp-value command.
  - To define a matching rule to match all packets, run the if-match [ ipv6 ] any command.
  - To define a matching rule to classify traffic based on the value of the next IPv6 header, run the if-match ipv6 next-header header-number first-next-header command.
  - To define a matching rule to classify traffic based on the source IPv6 address, run the if-match ipv6 source-address ipv6-address prefix-length command.
  - To define a matching rule to classify traffic based on a destination IPv6 address, run the if-match ipv6 destination-address ipv6-address prefix-length command.
  - To define a matching rule to classify traffic based on the source or destination QoS policy ID, run the if-match qos-local-id qos-local-id command.
  - To define a matching rule to classify traffic based on the QoS policy ID, run the if-match qos-local-id qos-local-id command.
  - To define a matching rule to classify traffic based on the source and destination QoS policy IDs, run the if-match qos-local-id source source-qos-local-id destination destination-qos-local-id command.
  - To define a matching rule to classify traffic based on the IPv6 QoS policy ID, run the if-match ipv6 qos-local-id qos-local-id command.
  - To define a matching rule to classify traffic based on the IPv6 QoS policy ID, run the if-match ipv6 qos-local-id qos-local-id command.
  For IPv6 packets, you need to specify the keyword ipv6 when defining a matching rule in Step 3. A matching rule defined to match packets based on the source or destination addresses applies to IPv6 packets, but not IPv4 packets.
  
  You can define different ACL rules as required, including the protocol type, source address, destination address, and ToS in packets. The if-match acl command filters packets according to the ACL rules defined in the rule command. The system then performs the corresponding traffic behavior for the matching packets.
4. Run commit
  The configuration is committed.

Define a traffic classifier based on Layer 2 information

Run system-view
The system view is displayed.
Run traffic classifier classifier-name [ operator { and | or } ]
A traffic classifier is configured, and the traffic classifier view is displayed.

If multiple matching rules are defined for the same traffic classifier, you can set their logical relationships by specifying the parameter operator. For details, see the previous section.

Define matching rules on the router as required.

To define a matching rule to classify traffic based on the ACL number, run the if-match [ ipv6 ] acl { acl-number | name acl-name } [ precedence precedence-value ] command.
To define a matching rule to classify traffic based on the 802.1p priority of VLAN packets, run the if-match 8021p 8021p-value command.
To define a matching rule to classify traffic based on the COS , run the if-match service-class service-class-value command.
To define a matching rule to classify traffic based on the source MAC address, run the if-match source-mac mac-address command.
To define a matching rule to classify traffic based on the destination MAC address, run the if-match destination-mac mac-address command.
To define a matching rule to classify traffic based on the VLAN, run the if-match vlan vlan-id [ cvlan ce-vlan-id ].

If multiple traffic classifiers are configured in one traffic policy, the traffic behaviors corresponding to these traffic classifiers are implemented in different orders.

When multiple traffic classifiers match different fields of an IP packet, the traffic behavior of the traffic classifier that is first bound to a traffic policy is preferentially implemented.

For example, as shown in Table 1, Policy 1 defines two traffic classifiers and their corresponding traffic behaviors in sequence. If a packet matches both of the traffic classifiers, behavior 1 is performed on the packet, and the 802.1p value of the packet is re-marked as 1.

**Table 1** Traffic classifiers and behaviors defined in Policy 1
Traffic Classifier	Matching Rule	Traffic Behavior	Traffic Action
Classifier 1	Matching the destination MAC address	Behavior 1	Re-marking the 802.1p value as 1
Classifier 3	Matching the source MAC address	Behavior 3	Re-marking the 802.1p value as 3

When multiple traffic classifiers match the same field of an IP packet, the traffic behavior corresponding to the specific traffic classifier is implemented for the packet.

For example, as shown in Table 2, three traffic classifiers and their corresponding traffic behaviors are associated with Policy 2 in sequence. If the destination MAC address of a packet is 2-2-2, behavior 2 is performed on the packet, and the 802.1p value of the packet is re-marked as 2.

**Table 2** Traffic classifiers and behaviors defined in Policy 2
Traffic Classifier	Matching Rule	Traffic Behavior	Traffic Action
Classifier 1	Matching the destination MAC address 1-1-1	Behavior 1	Re-marking the 802.1p value as 1
Classifier 2	Matching the destination MAC address 2-2-2	Behavior 2	Re-marking the 802.1p value as 2
Classifier 3	Matching the destination MAC address 3-3-3	Behavior 3	Re-marking the 802.1p value as 3

Run commit
The configuration is committed.