Notes on changing priority settings

If you try to modify the priority associated with a DSCP codepoint in a DSCP policy using the qos dscp-map priority command, and if the DSCP policy is currently used by one or more global QoS or classifier-based QoS policies, the following error message is displayed:

Cannot modify DSCP Policy codepoint - in use by other qos rules.

In this case, enter the following QoS show commands to identify in which global and classifier-based QoS configurations the DSCP policy is currently used:

show policy qos-policy

show qos tcp-udp-port-priority

show qos device-priority

show qos type-of-service

show qos protocol

show qos vlan

show qos port-priority

After determining the QoS configurations in which the DSCP-priority mapping is used, you can either delete a QoS configuration and reset the DSCP-priority mapping to No-override, or change either the 802.1p priority or the codepoint used in the QoS configuration.

Changing the priority of a codepoint

If codepoint 000001 is currently mapped to priority 6, and several global QoS policies use this codepoint to assign a priority to their respective types of matching traffic, you can change the priority associated with the codepoint using the following procedure.

  1. Identify the global and classifier-based QoS policies that use the codepoint.

  2. Do one of the following:
    1. Reconfigure each QoS policy by re-entering a different DSCP codepoint or a different 802.1p priority associated with the codepoint.

    2. Enter the no qos classifier or no policy qos-policy command to remove the current DSCP policy with codepoint 000001 and reset the priority to No-override.

  3. Use the qos dscp-map 000001 priority 0 - 7 command to remap DSCP 000001 to the desired priority.

  4. Do one of the following:
    1. Reconfigure codepoint 000001 in the QoS policies in which you want to use the new DSCP-priority mapping to mark matching packets.

    2. Leave a QoS policy in which you use DSCP 000001 to mark matching packets with the associated No-override priority mapping.