spanning-tree port-priority

To set an interface priority when two bridges compete for position as the root bridge, use the spanning-tree port-priority command. The priority you set breaks the tie. To return to the default settings, use the no form of this command.

spanning-tree [vlan vlan-id] port-priority value

no spanning-tree [vlan vlan-id] port-priority

Syntax Description

vlan vlan-id

(Optional) Specifies the VLAN identification number. The range is from 0 to 4094.

value

Port priority. The range is from 1 to 224, in increments of 32.


Command Default

Port priority default value is 128.

Command Modes

Interface configuration mode

Command History

Release
Modification

4.0(0)N1(1a)

This command was introduced.


Usage Guidelines

Do not use the vlan vlan-id parameter on access ports. The software uses the port priority value for access ports and the VLAN port priority values for trunk ports.

The priority values are 0, 32, 64, 96, 128, 160, 192, and 224. All other values are rejected.


Note Use this command to configure the port priority for Rapid per VLAN Spanning Tree Plus (Rapid PVST+) spanning tree mode, which is the default STP mode. To configure the port priority for Multiple Spanning Tree (MST) spanning tree mode, use the spacing-tree mst port-priority command.


Examples

This example shows how to increase the probability that the spanning tree instance on access port interface 2/0 is chosen as the root bridge by changing the port priority to 32:

switch(config-if)# spanning-tree port-priority 32  

Related Commands

Command
Description

show spanning-tree

Displays information about the spanning tree state.

spanning-tree interface priority

Displays information on the spanning tree port priority for the interface.