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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 39 Configuring QoS
Configuring Standard QoS
3 : 03 03 00 04 04 04 04 04 04 04
4 : 00 05 05 05 05 05 05 05 00 06
5 : 00 06 06 06 06 06 07 07 07 07
6 : 07 07 07 07
Note In the above DSCP-to-CoS map, the CoS values are shown in the body of the matrix. The d1 column
specifies the most-significant digit of the DSCP; the d2 row specifies the least-significant digit of the
DSCP. The intersection of the d1 and d2 values provides the CoS value. For example, in the
DSCP-to-CoS map, a DSCP value of 08 corresponds to a CoS value of 0.
Configuring the DSCP-to-DSCP-Mutation Map
If two QoS domains have different DSCP definitions, use the DSCP-to-DSCP-mutation map to translate
one set of DSCP values to match the definition of another domain. You apply the
DSCP-to-DSCP-mutation map to the receiving port (ingress mutation) at the boundary of a QoS
administrative domain.
With ingress mutation, the new DSCP value overwrites the one in the packet, and QoS treats the packet
with this new value. The switch sends the packet out the port with the new DSCP value.
You can configure multiple DSCP-to-DSCP-mutation maps on an ingress port. The default
DSCP-to-DSCP-mutation map is a null map, which maps an incoming DSCP value to the same DSCP
value.
Beginning in privileged EXEC mode, follow these steps to modify the DSCP-to-DSCP-mutation map.
This procedure is optional.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 mls qos map dscp-mutation
dscp-mutation-name in-dscp to out-dscp Modify the DSCP-to-DSCP-mutation map.
For dscp-mutation-name, enter the mutation map name. You can
create more than one map by specifying a new name.
For in-dscp, enter up to eight DSCP values separated by spaces.
Then enter the to keyword.
For out-dscp, enter a single DSCP value.
The DSCP range is 0 to 63.
Step 3 interface interface-id Specify the port to which to attach the map, and enter interface
configuration mode.
Valid interfaces include physical ports.
Step 4 mls qos trust dscp Configure the ingress port as a DSCP-trusted port. By default, the port
is not trusted.
Step 5 mls qos dscp-mutation
dscp-mutation-name Apply the map to the specified ingress DSCP-trusted port.
For dscp-mutation-name, enter the mutation map name specified in
Step 2.
Step 6 end Return to privileged EXEC mode.
Step 7 show mls qos maps dscp-mutation Verify your entries.
Step 8 copy running-config startup-config (Optional) Save your entries in the configuration file.