Spanning Tree Protocol Configuration Guide, Cisco Catalyst IE9300 Rugged Series Switches

PDF

Spanning Tree Protocol Configuration Guide, Cisco Catalyst IE9300 Rugged Series Switches

Configure port priority for an interface

Updated: March 2, 2026

Want to summarize with AI?

Log in

Learn how to configure the port priority for an interface to control which interface spanning tree selects when a loop occurs.

You can configure the port priority for an interface to control which interface spanning tree selects when a loop occurs.

This task allows you to assign higher priority values (lower numerical values) to interfaces you want selected first and lower priority values (higher numerical values) to interfaces you want selected last. If all interfaces have the same priority value, spanning tree places the interface with the lowest interface number into the forwarding state.

Before you begin

Perform these steps to configure port priority for an interface.

Procedure

1.

Use the enable command to enter privileged EXEC mode.

Example:

Switch> enable

Enter your password if prompted.
2.

Use the configure terminal command to enter global configuration mode.

Example:

Switch# configure terminal
3.

Use the interface interface-id command to specify an interface to configure and enter interface configuration mode.

Example:

Switch(config)# interface gigabitethernet 1/0/10

Valid interfaces include physical ports and port-channel logical interfaces such as port-channel followed by the port channel number.
4.

Use the spanning-tree port-priority priority command to configure the port priority for an interface.

Example:

Switch(config-if)# spanning-tree port-priority 96

For priority, range is 0 to 240, in increments of 16. The default is 128. Valid values are 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, and 240. Other values are not accepted. A lower value indicates a higher priority.
5.

Use the spanning-tree vlan vlan-id port-priority priority command to configure the port priority for a VLAN.

Example:

Switch(config-if)# spanning-tree vlan 100 port-priority 96

For vlan-id, you can specify a single VLAN identified by VLAN ID number, a range of VLANs separated by a hyphen, or a series of VLANs separated by a comma. The valid range is 1 to 4094.

For priority, the range is 0 to 240, in increments of 16. The default is 128.

6.

Use the end command to return to privileged EXEC mode.

Example:

Switch(config)# end