Cisco Catalyst 3550 Series User Manual

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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 29 Configuring QoS
Configuring Standard QoS
This example shows how to map DSCP values 0, 8, 16, 24, 32, 40, 48, and 50 to CoS value 0:
Switch# configure terminal
Switch(config)# mls qos map dscp-cos 0 8 16 24 32 40 48 50 to 0
Switch(config)# end
Switch# show mls qos maps dscp-cos
Dscp-cos map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 00 00 00 00 00 00 00 00 01
1 : 01 01 01 01 01 01 00 02 02 02
2 : 02 02 02 02 00 03 03 03 03 03
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 this 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 gives 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
You apply the DSCP-to-DSCP-mutation map to a port at the boundary of a QoS administrative domain.
If the two domains have different DSCP definitions between them, 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 DSCP-to-DSCP-mutation map:
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, with each value
separated by a space. Then enter the to keyword.
• For out-dscp, enter a single DSCP value.
The range is 0 to 63.
Step 3
interface interface-id Enter interface configuration mode, and specify the interface to which
to attach the map.
Valid interfaces include physical interfaces.
Step 4
mls qos trust dscp Configure the ingress port as a DSCP-trusted port.

Cisco Catalyst 3550 Series Specifications

General

Brand	Cisco
Model	Catalyst 3550 Series
Category	Network Router
Language	English