Applying a Traffic Class to DSCP Map to an Egress Interface

A QoS traffic class-to-DSCP map has been configured.
For Extreme 8720, Extreme 8520, SLX 9250, and SLX 9150 devices, a L2 switch port needs qos remark dscp be enabled before applying “qos traffic class-to-DSCP map”. On L2 switch port “qos remark dscp” cannot be disabled before removing “qos traffic class-to-DSCP map”.

Enter global configuration mode.
```
device# configure terminal
```
Enter interface configuration mode.
```
device(config)# interface ethernet 2/2
```
Apply the configured QoS traffic class-to-DSCP map to the interface.
```
device(conf-if-eth-2/2)# qos traffic-class-cos TcDscpMap
```
Return to privileged exec mode.
```
 device(conf-if-eth-2/2)# end 
```

Verify the configuration.

device# show qos maps traffic-class-dscp
          [Note: CoS = Class of Service, TC = Traffic Class, DP = Drop Precedence,DSCP = Differentiated Services Code Point]
  TC-to-DSCP Map: TcDscpMap
  In-TC:  0   1   2   3   4   5   6   7
  ----------------------------------------------
  Out-DSCP(DP=0): 00  08  16  24  32  40  48  56
  Out-DSCP(DP=1): 00  30  16  24  32  40  48  56
  Out-DSCP(DP=2): 00  08  16  61  32  40  48  56
  Out-DSCP(DP=3): 00  08  16  24  32  40  48  56     

  Enabled on the following interfaces: Eth 0/2

Save the running-config file to the startup-config file.
```
device# copy running-config startup-config
```

The following example shows how to apply a QoS traffic class-to-CoS map to an egress interface.

 device# configure terminal 
device(config)# interface ethernet 2/2 
device(conf-if-eth-2/2)# qos traffic-class-cos TcDscpMap
device(conf-if-eth-2/2)# end 
device# show qos maps traffic-class-dscp
device# copy running-config startup-config