This article explains SRX/J traffic classification based on checking Layer 2 or Layer 3.
Packets entering the device can be classified by an explicit set of configuration statements to place them in certain forwarding classes with a loss priority by checking the Layer 2 (IEEE 802.1p) or Layer 3 (IPv4 precedence, IPv4 DSCP and IPv6 DSCP) CoS bits already set in the headers, as received from the peer devices.
In specific requirements, when the packets are required to be classified based upon the IEEE 802.1p bits set in a Layer 2 header, the only option is to use the Behavioral Aggregate Classifiers, as Multi-field classifiers do not provide an option to match the IEEE 802.1p bits for classification.
The packets can be classified into required forwarding classes along with the loss priority by using the Behavioral Aggregate Classifiers.
The following section shows a sample configuration for the same :
[edit class-of-service] root# show classifiers { ieee-802.1 L2_test_classifier { forwarding-class expedited-forwarding { loss-priority low code-points ef; } } }
[edit class-of-service interfaces ge-0/0/0 unit 0] root# show classifiers { ieee-802.1 L2_test_classifier; }
The above set of statements place the packets in the forwarding class expedited-forwarding with a loss priority of low when the IEEE 802.1p bits correspond to the ef code points.
ef
root@> show class-of-service classifier type ieee-802.1 Classifier: ieee8021p-default, Code point type: ieee-802.1, Index: 11 Code point Forwarding class Loss priority 000 best-effort low 001 best-effort high 010 expedited-forwarding low 011 expedited-forwarding high 100 assured-forwarding low 101 assured-forwarding high 110 network-control low 111 network-control high Classifier: L2_test_classifier, Code point type: ieee-802.1, Index: 6748 Code point Forwarding class Loss priority 010 expedited-forwarding low