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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter20 Configuring QoS Configuring QoS
Configuring the DSCP-to-DSCP-Mutation Map
You apply the DSCP-to-DSCP-mutation map to a port at the boundary of a QoS administrativ e domain.
If the two domains have different DSCP definitions between them, you use the DSCP-to -DSCP-mutation
map to translate a set of DSCP values to match the definition of the other domain.
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 DSC P-t o-DS CP-mu tati on map:
To return to the default map, use the no mls qos dscp-mutation dscp-mutation-name global
configuration command.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 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 8 DSCP values separated by spaces. Then
enter the to keyword.
•For out-dscp, enter up to 8 DSCP values separated by spaces.
The DSCP range is 0 to 63.
Step3 interface interface-id Enter interface configuration mode, and specify the interface to which
to attach the map.
Valid interfaces include physical interfaces.
Step4 mls qos trust dscp Configure the ingress port as a DSCP-trusted port.
Step5 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.
You can apply the map to different Gigabit-capable Ethernet ports.
However, on 10/100 Ethernet ports, you can attach only one
DSCP-to-DSCP-mutation map to a group of twelve ports. For example,
Fast Ethernet ports 0/1 to 0/12 are a group, Fast Ethernet ports 0/13 to
0/24 are a group, Gigabit Ethernet port 0/1 is a group, an d Giga bit
Ethernet port 0/2 is a group. When applying a mutation map to any port
in a group, all ports in the same group are automatically configured
with the same map.
Step6 end Return to privileged EXEC mode.
Step7 show mls qos maps dscp-mutation Verify your entries.
Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.