Configuring the CoStoDSCP Map
You use the CoS-to-DSCP map to map CoS values in incoming packets to a DSCP value that QoS uses internally to represent the priority of the traffic.
Table 24-3 shows the default CoS-to-DSCP map.
Table 24-3 Default CoS-to-DSCP Map
Table 24-3 Default CoS-to-DSCP Map
|
CoS value |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
|
DSCP value |
0 |
8 |
16 |
24 |
32 |
40 |
48 |
56 |
If these values are not appropriate for your network, you need to modify them. Beginning in privileged EXEC mode, follow these steps to modify the CoS-to-DSCP map:
Stepl Step 2
Stepl Step 2
Step 3 Step 4 Step 5
|
Command |
Purpose |
|
configure terminal |
Enter global configuration mode. |
|
mls qos map cos-dscp dscp1...dscp8 |
Modify the CoS-to-DSCP map. For dscp1...dscp8, enter 8 DSCP values that correspond to CoS values 0 to 7. Separate each DSCP value with a space. The supported DSCP values are 0, 8, 10, 16,18,24,26,32, 34, 40, 46, 48, and 56. |
|
end |
Return to privileged EXEC mode. |
|
show mls qos maps cos-dscp |
Verify your entries. |
|
copy running-config startup-config |
(Optional) Save your entries in the configuration file. |
To return to the default map, use the no mls qos map cos-dscp global configuration command. This example shows how to modify and display the CoS-to-DSCP map:
Switch# configure terminal
Switch(config)#mls qos map cos-dscp 8 8 8 8 24 32 56 56
Switch(config)# end
Switch# show mls qos maps cos-dscp
Step 3 Step 4 Step 5
To return to the default map, use the no mls qos map cos-dscp global configuration command. This example shows how to modify and display the CoS-to-DSCP map:
Switch# configure terminal
Switch(config)#mls qos map cos-dscp 8 8 8 8 24 32 56 56
Switch(config)# end
Switch# show mls qos maps cos-dscp
Cos-dscp map:
cos: 01234567
dscp: 8 8 8 8 24 32 56 56
Continue reading here: Understanding Ether Channels
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