Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring QoS
Configuring Standard QoS
Beginning in privileged EXEC mode, follow these steps to modify the DSCP-to-CoS map. This
procedure is optional.
To return to the default map, use the no mls qos dscp-cos global configuration command.
This example shows how to map DSCP values 0, 8, 16, 24, 32, 40, 48, and 50 to CoS value 0 and to
display the map:
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 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.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 mls qos map dscp-cos dscp-list to cos Modify the DSCP-to-CoS map.
• For dscp-list , enter up to eight DSCP values separated by spaces.
Then enter the to keyword.
•
For cos , enter the CoS value to which the DSCP values correspond.
The DSCP range is 0 to 63; the CoS range is 0 to 7.
Step 3 end Return to privileged EXEC mode.
Step 4 show mls qos maps dscp-to-cos Verify your entries.
Step 5 copy running-config startup-config (Optional) Save your entries in the configuration file.