Configuring The Dscp-To-Dscp-Mutation Map - Cisco Catalyst 3750 Software Configuration Manual

Chapter 26 Configuring QoS

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 and apply them to traffic received on a port.
The default DSCP-to-DSCP-mutation map is a null map, which maps an inbound 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
Step 1 configure terminal
Step 2
mls qos map dscp-mutation
dscp-mutation-name in-dscp to out-dscp
Step 3
interface interface-id
Step 4 mls qos trust dscp
Step 5
mls qos dscp-mutation
dscp-mutation-name
Step 6
end
Step 7 show mls qos maps dscp-mutation
Step 8 copy running-config startup-config
To return to the default map, use the no mls qos dscp-mutation dscp-mutation-name global
configuration command.
This example shows how to define the DSCP-to-DSCP-mutation map. All the entries that are not
explicitly configured are not modified (remains as specified in the null map).
Switch(config)# mls qos map dscp-mutation mutation1 1 2 3 4 5 6 7 to 0
Switch(config)# mls qos map dscp-mutation mutation1 8 9 10 11 12 13 to 10
Switch(config)# mls qos map dscp-mutation mutation1 20 21 22 to 20
Switch(config)# mls qos map dscp-mutation mutation1 30 31 32 33 34 to 30
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# mls qos trust dscp
78-15870-01
Purpose
Enter global configuration mode.
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.
Specify the port to which to attach the map, and enter interface
configuration mode.
Valid interfaces include physical ports.
Configure the ingress port as a DSCP-trusted port. By default, the port
is not trusted.
Apply the map to the specified ingress DSCP-trusted port.
For dscp-mutation-name, enter the mutation map name specified in
Step 2.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Metro Switch Software Configuration Guide
Configuring Standard QoS
26-63