Example: Configuring Forwarding Class Sets

Requirements

• A Juniper Networks QFX3500 Switch
• Junos OS Release 11.1 or later for the QFX Series

Overview

You can configure up to three unicast fc-sets and one multicast fc-set. A common way to configure unicast priority groups is to configure separate fc-sets for local area network (LAN) traffic, storage area network (SAN) traffic, and high-performance computing (HPC) traffic, and then assign the appropriate forwarding classes to each fc-set.

Note: If you configure strict-high priority queues, you must create an fc-set that is dedicated only to strict-high priority traffic. Only one fc-set can contain strict-high priority queues. Queues that are not strict-high priority cannot belong to the same fc-set as strict-high priority queues. The multidestination fc-set cannot contain strict-high priority queues.

To apply ETS, you map one or more fc-sets to a physical egress port. You can map up to three forwarding class sets to each port. When you map an fc-set to a port, the port uses hierarchical scheduling to allocate port resources to the priority group (fc-set) and to allocate the priority group resources to the queues (forwarding classes) that belong to the priority group.

This example describes how to:

• Configure three fc-sets called lan-pg, san-pg, and hpc-pg.
• Assign forwarding classes to each of the fc-sets.
• Apply the fc-sets and their output traffic control profiles to an egress interface.

This example does not describe how to configure the forwarding classes assigned to the fc-sets or how to configure traffic control profiles. Table 1 shows the configuration components for this example:

Configuring Forwarding Class Sets

Step-by-Step Procedure

1. Define the lan-pg priority group (fc-set) and assign to it the forwarding classes best-effort-1 and best-effort-2:
   [edit class-of-service]
user@switch# set forwarding-class-sets lan-pg class best-effort-1
user@switch# set forwarding-class-sets lan-pg class best-effort-2

   
   

2. Define the san-pg priority group and assign to it the forwarding classes fcoe and fcoe-2:
   [edit class-of-service]
user@switch# set forwarding-class-sets san-pg class fcoe
user@switch# set forwarding-class-sets san-pg class fcoe-2

   
   

3. Define the hpc-pg priority group and assign to it the forwarding classes nc and high-perf:
   [edit class-of-service]
user@switch# set forwarding-class-sets hpc-pg class nc
user@switch# set forwarding-class-sets hpc-pg class high-perf

   
   

4. Map the three forwarding class sets to an interface (the output traffic control profiles associated with the forwarding class sets determine the class of service scheduling for the priority groups):
   [edit class-of-service]
user@switch# set interfaces xe-0/0/7 forwarding-class-set lan-pg output-traffic-control-profile lan-tcp
user@switch# set interfaces xe-0/0/7 forwarding-class-set san-pg output-traffic-control-profile san-tcp
user@switch# set interfaces xe-0/0/7 forwarding-class-set hpc-pg output-traffic-control-profile hpc-tcp

   
   

Verification

To verify the priority group configuration, perform these tasks:

• Verifying Forwarding Class Set Membership
• Verifying the Egress Interface Configuration

Verifying Forwarding Class Set Membership

Purpose

Verify that you configured the lan-pg, san-pg, and hpc-pg priority groups with the correct forwarding classes.

Action

List the forwarding class set member configuration using the operational mode command show configuration class-of-service forwarding-class-sets:

lan-pg {
    class best-effort-1;
    class best-effort-2;
}
san-pg {
    class fcoe;
    class fcoe-2;
}
hpc-pg {
    class high-perf;
    class nc;
}

Verifying the Egress Interface Configuration

Purpose

Verify that egress interface xe-0/0/7 is associated with the lan-pg, san-pg, and hpc-pg priority groups and with the correct output traffic control profiles.

Action

Display the egress interface using the operational mode command show configuration class-of-service interfaces xe-0/0/7:

forwarding-class-set {
    lan-pg {
        output-traffic-control-profile lan-tcp;
    }
    san-pg {
        output-traffic-control-profile san-tcp;
    }
    hpc-pg {
        output-traffic-control-profile hpc-tcp;
    }
}