Determining which port to use for forwarding

Syntax:

spanning-tree port-list priority priority-multiplier

MSTP uses this parameter to determine the port to use for forwarding. The port with the lowest priority number has the highest priority for use.

The range is 0 to 240, and is configured by specifying a multiplier from 0 - 15. When you specify a priority multiplier of 0 - 15, the actual priority assigned to the switch is:

(priority-multiplier) x 16

If you configure 2 as the priority multiplier on a given port, the actual Priority setting is 32. After specifying the port priority multiplier, the switch displays the actual port priority (and not the multiplier) in the show spanning-tree or show spanning-tree port-list displays.

You can view the actual multiplier setting for ports by executing show running and looking for an entry in this format:

spanning-treeport-list priority priority-multiplier

For example, configuring port A2 with a priority multiplier of 3 results in the following line in the show running output:

spanning-tree A2 priority 3