Assigning a priority based on source-port

This option assigns a priority to all outbound packets having the specified source-port. You can configure this option by either specifying the source-port ahead of the qos command or moving to the port context for the port you want to configure for priority. (If you are configuring multiple source-ports with the same priority, you may find it easier to use the interface <port-list> command to go to the port context instead of individually configuring the priority for each port.)

Syntax:


interface <port-list> qos priority <0-7>

Configures an 802.1p priority for packets entering the switch through the specified (source) ports. This priority determines the packet queue in the outbound ports to which traffic is sent. If a 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 source-port or group of source-ports.

(Default: No-override)

Syntax:


no interface <port-list> qos

Disables use of the specified source-ports for QoS classifiers and resets the priority for the specified sourceports to No-override.

Syntax:


show qos port-priority

Lists the QoS port-priority classifiers with their priority data.

For example, suppose that you want to prioritize inbound traffic on the following source-ports:

Source-port

Priority

1–3

2

4

3

You would then execute the following commands to prioritize traffic received on the above ports.

Configuring and displaying source-port QoS priorities

switch(config)# interface e 1-3 qos priority 2
switch(config)# interface e 4 qos priority 3
switch(config)# show qos port-priority

  Port priorities
  
  Port Apply rule  | DSCP  Priority    Radius Override
  ---- ----------    ----  --------    ---------------
  1    Priority    |       2           No-override
  2    Priority    |       2           No-override
  3    Priority    |       2           No-override
  4    Priority    |       3           No-override
  5    No-override |       No-override No-override
  .    .                   .           .
  .    .                   .           .

If you then decided to remove port 1 from QoS prioritization:

Returning a QoS-prioritized VLAN to “No-override” status

In this instance, No-override indicates that port 1 is not prioritized by QoS.

switch(config)# no interface 1 qos
switch(config)# show qos port-priority

  Port priorities
  
  Port Apply rule  | DSCP  Priority    Radius Override
  ---- ----------    ----  --------    ---------------
  1    No-override |       No-override No-override
  2    Priority    |       2           No-override
  3    Priority    |       2           No-override
  4    Priority    |       3           No-override
  5    No-override |       No-override No-override
  .    .                   .           .
  .    .                   .           .