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Example: Configuring Classifiers
Packet classification associates incoming packets with a particular CoS servicing level. Classifiers associate packets with a forwarding class and loss priority and assign packets to output queues based on the associated forwarding class. You apply classifiers to ingress interfaces.
Configuring Classifiers
Step-by-Step Procedure
To configure an IEEE 802.1 BA classifier named ba-classifier as the default IEEE 802.1 classifier:
Associate code point
000with forwarding classbeand loss prioritylow:[edit class-of-service classifiers] user@switch# set ieee-802.1 ba-classifier import default forwarding-class be loss-priority low code-points 000
Associate code point
011with forwarding classfcoeand loss prioritylow:[edit class-of-service classifiers] user@switch# set ieee-802.1 ba-classifier forwarding-class fcoe loss-priority low code-points 011
Associate code point
100with forwarding classno-lossand loss prioritylow:[edit class-of-service classifiers] user@switch# set ieee-802.1 ba-classifier forwarding-class no-loss loss-priority low code-points 100
Associate code point
110with forwarding classncand loss prioritylow:[edit class-of-service classifiers] user@switch# set ieee-802.1 ba-classifier forwarding-class nc loss-priority low code-points 110
Apply the classifier to ingress interface
xe-0/0/10:[edit class-of-service interfaces] user@switch# set xe-0/0/10 unit 0 classifiers ieee-802.1 ba-classifier
Requirements
This example uses the following hardware and software components:
One switch.
Junos OS Release 15.1X53-D10 or later for the QFX Series.
Overview
Junos OS supports three general types of classifiers:
Behavior aggregate or CoS value traffic classifiers—Examine the CoS value in the packet header. The value in this single field determines the CoS settings applied to the packet. BA classifiers allow you to set the forwarding class and loss priority of a packet based on the Differentiated Services code point (DSCP or DSCP IPv6) value, IEEE 802.1p value, or MPLS EXP value. (EXP classifiers can be applied only to
family mplsinterfaces.)Fixed classifiers. Fixed classifiers classify all ingress traffic on a physical interface into one forwarding class, regardless of the CoS bits in the VLAN header or the DSCP bits in the IP packet header.
Multifield traffic classifiers—Examine multiple fields in the packet, such as source and destination addresses and source and destination port numbers of the packet. With multifield classifiers, you set the forwarding class and loss priority of a packet based on firewall filter rules.
This example describes how to configure a BA classifier called ba-classifier as the default IEEE 802.1 mapping of incoming traffic to forwarding classes, and apply it to ingress interface xe-0/0/10. The BA classifier assigns loss priorities, as shown in Table 1, to incoming packets in the four default forwarding classes. You can adapt the example to DSCP traffic by specifying a DSCP classifier instead of an IEEE classifier, and by applying DSCP bits instead of CoS bits.
To set multifield classifiers, use firewall filter rules.
Forwarding Class |
CoS Traffic Type |
ba-classifier Loss Priority to IEEE 802.1p Code Point Mapping |
Packet Drop Attribute |
|---|---|---|---|
|
Best-effort traffic |
Low loss priority code point: |
drop |
|
Guaranteed delivery for Fibre Channel over Ethernet (FCoE) traffic |
Low loss priority code point: |
no-loss |
|
Guaranteed delivery for TCP traffic |
Low loss priority code point: |
no-loss |
|
Network-control traffic |
Low loss priority code point: |
drop |
Verification
To verify the classifier configuration, perform these tasks:
Verifying the Classifier Configuration
Purpose
Verify that you configured the classifier with the correct forwarding classes, loss priorities, and code points.
Action
List the classifier configuration using the operational mode command show configuration class-of-service classifiers ieee-802.1 ba-classifier:
user@switch> show configuration class-of-service classifiers ieee-802.1 ba-classifier
forwarding-class be {
loss-priority low code-points 000;
}
forwarding-class fcoe {
loss-priority low code-points 011;
}
forwarding-class no-loss {
loss-priority low code-points 100;
}
forwarding-class nc
loss-priority low code-points 110;
}Verifying the Ingress Interface Configuration
Purpose
Verify that the classifier ba-classifier is attached to ingress interface xe-0/0/10.
Action
List the ingress interface using the operational mode command show configuration class-of-service interfaces xe-0/0/10:
user@switch> show configuration class-of-service interfaces xe-0/0/10
congestion-notification-profile fcoe-cnp;
unit 0 {
classifiers {
ieee-802.1 ba-classifier;
}
}