Cisco Systems 3560 사용자 설명서

The show spanning-tree mst interface interface-id privileged EXEC command displays information 
only if the port is in a link-up operative state. Otherwise, you can use the show running-config interface 
privileged EXEC command to confirm the configuration.

To return the interface to its default setting, use the no spanning-tree mst instance-id port-priority 
interface configuration command.

The MSTP path cost default value is derived from the media speed of an interface. If a loop occurs, the 
MSTP uses cost when selecting an interface to put in the forwarding state. You can assign lower cost 
values to interfaces that you want selected first and higher cost values that you want selected last. If all 
interfaces have the same cost value, the MSTP puts the interface with the lowest interface number in the 
forwarding state and blocks the other interfaces.

Beginning in privileged EXEC mode, follow these steps to configure the MSTP cost of an interface. This 
procedure is optional.

spanning-tree mst instance-id port-priority priority

Configure the port priority. 

For instance-id, 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.

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

The 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. 

Return to privileged EXEC mode.

show spanning-tree mst interface interface-id

or

show spanning-tree mst instance-id

Verify your entries.

(Optional) Save your entries in the configuration file.

Enter global configuration mode.

interface interface-id

Specify an interface to configure, and enter interface 
configuration mode. Valid interfaces include physical ports and 
port-channel logical interfaces. The port-channel range is 1 to 48.