Spanning-Tree Port-Priority - Cisco catalyst 3750 Command Reference Manual

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands

spanning-tree port-priority

Use the spanning-tree port-priority interface configuration command to configure an interface
priority. If a loop occurs, spanning tree can find the interface to put in the forwarding state. Use the no
form of this command to return to the default setting.
Syntax Description
vlan vlan-id
priority
Defaults The default is 128.
Command Modes
Interface configuration
Command History Release
12.1(11)AX
12.1(14)EA1
Usage Guidelines If the variable vlan-id is omitted, the command applies to the spanning-tree instance associated with
VLAN 1.
You can set the priority on a VLAN that has no interfaces assigned to it. The setting takes effect when
you assign the interface to the VLAN.
If you configure an interface with both the spanning-tree vlan vlan-id port-priority priority command
and the spanning-tree port-priority priority command, the spanning-tree vlan vlan-id port-priority
priority command takes effect.
If your switch is a member of a switch stack, you must use the spanning-tree [vlan vlan-id] cost cost
interface configuration command instead of the spanning-tree [vlan vlan-id] port-priority priority
interface configuration command to select an interface to put in the forwarding state. Assign lower cost
values to interfaces that you want selected first and higher cost values that you want selected last.
Examples
This example shows how to increase the likelihood that a port will be put in the forwarding state if a
loop occurs:
Switch(config)# interface gigabitethernet2/0/2
OL-8552-07
spanning-tree [vlan vlan-id] port-priority priority
no spanning-tree [vlan vlan-id] port-priority
(Optional) VLAN range associated with a spanning-tree instance. 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 range is 1 to 4094.
Number from 0 to 240, in increments of 16. Valid values are 0, 16, 32, 48, 64, 80,
96, 112, 128, 144, 160, 176, 192, 208, 224, and 240. All other values are rejected.
The lower the number, the higher the priority.
Modification
This command was introduced.
The value for the vlan-id variable was changed. The priority range values
changed.
spanning-tree port-priority
Catalyst 3750 Switch Command Reference
2-793