Quick Reference Guide

770 Spanning Tree Commands
Syntax
spanning-tree vlan { vlan-list } priority priority
no spanning-tree vlan { vlan-list } priority
• vlan-list –A single VLAN ID or a list of VLAN IDs in comma delineated or
range format with no embedded blanks. Range 1-4094.
•
priority –The bridge priority advertised when combined with the switch
MAC address. Range 0-61440.
Default Configuration
The default bridge priority is 32768.
Valid values are 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768,
36864, 40960, 45056, 49152, 53248, 57344, and 61440. The default value is
32768.
If the value configured is not among the specifed values, it will be rounded off
to the nearest valid value.
Command Modes
Global Configuration mode
User Guidelines
This command can be configured even if the switch is configured for
MST(RSTP) mode. It is only used when the switch is configured for PVST or
RPVST modes.
The root bridge for a VLAN should be carefully selected to provide optimal
paths for traffic through the network. Generally, this means selecting a switch
that is well-connected with other switches in the network.
Example
This example configures a switch to be the spanning tree root bridge for
VLANs 12, 13, 24, 25, and 26. This presumes other switches in the network
utilize the default bridge priority configuration.
console(config)#spanning-tree vlan 12,13,24-26 priority 8192
2CSNXXX_SWUM200.book Page 770 Tuesday, December 10, 2013 1:22 PM