Administrator Guide

Layer 2 Switching Commands 776
spanning-tree mst priority
Use the spanning-tree mst priority command in Global Configuration mode
to set the switch priority for the specified spanning-tree instance. To return to
the default setting, use the no form of this command.
Syntax
spanning-tree mst instance-id priority priority
no spanning-tree mst instance-id priority
• instance-id —ID of the spanning-tree instance. (Range: 1-4094)
•
priority —Sets the switch priority for the specified spanning-tree instance.
This setting affects the likelihood that the switch is selected as the root
switch. A lower value increases the probability that the switch is selected as
the root switch. (Range: 0-61440)
Default Configuration
The default bridge priority for IEEE STP is 32768.
Command Mode
Global Configuration mode
User Guidelines
The priority value must be a multiple of 4096. The priority will be set to the
nearest multiple of 4096 if not an exact multiple of 4096.
Bridge priority configuration is given preference over the root
primary/secondary configuration. Root primary/secondary configuration is
given preference over the DRC configuration.
The switch with the lowest priority is selected as the root of the spanning tree.
Example
The following example configures the spanning tree priority of instance 1 to
4096.
console(config)#spanning-tree mst 1 priority 4096
2CSNXXX_SWUM204.book Page 776 Monday, January 25, 2016 1:25 PM