JN0-650: Enterprise Routing and Switching, Professional (JNCIP-ENT)

By Juniper · Question Mode

QuestionQ30

Class of Service (CoS)

You are configuring CoS across your enterprise network with DSCP. You have configured MF classification on your edge devices and use BA classifiers throughout the core. You are using the EZQoS template supplied on your EX Series switches, which act as the edge devices. You have loaded the configuration group and applied it to the applicable interfaces. Classification and scheduling operate correctly on the edge devices; however, traffic is not classified properly when it arrives at the core devices.

In this scenario, which statement is correct for resolving this problem?

Explanation

BA classifiers in the core use the DSCP code point carried in each packet to select a forwarding class and loss priority. An MF classifier at the edge assigns CoS treatment based on firewall-filter matches, but traffic must be marked on egress with a DSCP rewrite rule so that the downstream core BA classifier receives the intended DSCP value. Juniper documents that rewrite rules set CoS bits in outgoing packets so downstream devices can classify packets into the appropriate service group.

Learn more

Community Discussion

No comments yet. Be the first to start the discussion!