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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 14 Configuring MSTP
Configuring MSTP Features
Note
The show spanning-tree mst interface interface-id privileged EXEC command displays information
only for ports that are in a link-up operative state. Otherwise, you can use the show running-config
privileged EXEC command to confirm the configuration.
To return the interface to its default setting, use the no spanning-tree mst instance-id cost interface
configuration command.
Configuring the Switch Priority
You can configure the switch priority and make it more likely that the switch will be chosen as the root
switch.
Note
Exercise care when using this command. For most situations, we recommend that you use the
spanning-tree mst instance-id root primary and the spanning-tree mst instance-id root secondary
global configuration commands to modify the switch priority.
Beginning in privileged EXEC mode, follow these steps to configure the switch priority. This procedure
is optional.
To return the switch to its default setting, use the no spanning-tree mst instance-id priority global
configuration command.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
spanning-tree mst instance-id priority priority
Configure the switch 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 61440 in increments of
4096; the default is 32768. The lower the number, the
more likely the switch will be chosen as the root switch.
Priority values are 0, 4096, 8192, 12288, 16384, 20480,
24576, 28672, 32768, 36864, 40960, 45056, 49152,
53248, 57344, and 61440. All other values are rejected.
Step 3
end
Return to privileged EXEC mode.
Step 4
show spanning-tree mst instance-id
Verify your entries.
Step 5
copy running-config startup-config
(Optional) Save your entries in the configuration file.
