Assigning a priority for global VLAN-ID QoS

This global QoS packet-marking option assigns a priority to all packets received on the specified VLAN-ID (VID). You can configure this option by either specifying the VLAN-ID ahead of the qos command or moving to the VLAN context for the VLAN you want to configure for priority.

Syntax:

vlan vid qos priority 0 - 7

Configures an 802.1p priority for packets received from the specified VLAN. This priority determines the packet's queue in the outbound port to which it is sent. If the packet leaves the switch on a tagged port, it carries the 802.1p priority with it to the next downstream device. You can configure one QoS classifier for each VLAN-ID.

Default: No-override

no vlan vid qos

Removes the specified VLAN-ID as a QoS classifier and resets the priority for that VLAN to No-override.

show qos vlan-priority

Displays a listing of the QoS VLAN-ID classifiers currently in the running-config file, with their priority data.

Viewing the VLANs available for QoS prioritization

802.1p priorities are assigned to packets received in VLANs 1, 20, 30, and 40:

Enter the following commands to mark VLAN packets that match the specified VLAN IDs with an 802.1p priority:

switch(config)# vlan 1 qos priority 2
switch(config)# vlan 20 qos priority 5
switch(config)# vlan 30 qos priority 5
switch(config)# vlan 40 qos priority 7
switch(config)# show qos vlan

  VLAN priorities

  VLAN ID Apply rule  | DSCP   Priority
  ------- ------------+ ------ -------------
  1       Priority    |        2
  20      Priority    |        5
  30      Priority    |        5
  40      Priority    |        7

Returning a QoS-prioritized VLAN to "No-override" status

If later it is necessary to remove VLAN 20 from QoS prioritization, enter the following command: