Cisco ME 3600X, Command Reference Manual

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Cisco ME 3800X and ME 3600X Switch Command Reference
OL-28238-01
Chapter
spanning-tree mst port-priority
spanning-tree mst port-priority
To configure an interface priority, use the spanning-tree mst port-priority command in interface
configuration mode. If a loop occurs, the Multiple Spanning Tree Protocol (MSTP) can find the interface
to put in the forwarding state. To return to the default setting, use the
no form of this command.
spanning-tree mst instance-id port-priority priority
no spanning-tree mst instance-id port-priority
Syntax Description
Defaults The default is 128.
Command Modes Interface configuration
Command History
Usage Guidelines You can assign higher priority values (lower numerical values) to STP port that you want selected first
and lower priority values (higher numerical values) that you want selected last. If all STP ports have the
same priority value, the multiple spanning tree (MST) puts the interface with the lowest interface number
in the forwarding state and blocks other interfaces.
You can verify your settings by entering the show spanning-tree mst interface interface-id privileged
EXEC command.
Examples
This example shows how to increase the likelihood that the interface associated with spanning-tree
instances 20 and 22 is placed into the forwarding state if a loop occurs:
Switch(config)# interface gigabitethernet0/2
Switch(config-if)# spanning-tree mst 20,22 port-priority 0
instance-id Range of spanning-tree instances. You can specify a single instance, a range of
instances separated by a hyphen, or a series of instances separated by a comma. The
range is 0 to 4094.
priority The range is 0 to 240 in increments of 16. Valid priority 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.
Release Modification
12.2(52)EY This command was introduced.