Cisco Catalyst 2960 Series, Configuration Manual

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Exercise care when using this command. For normal network configurations, we recommend that you use
the
spanning-tree mst i nstance-id root primary and the spanning-tree mst instance-id root secondary
global configuration commands to specify a switch as the root or secondary root switch. You should
modify the switch priority only in circumstances where these commands do not work.
Note
This procedure is optional.
Before You Begin
A multiple spanning tree (MST) must be specified and enabled on the switch. For instructions, see Related
Topics.
You must also know the specified MST instance ID used. This example uses 0 as the instance ID because
that was the instance ID set up by the instructions listed under Related Topics.
SUMMARY STEPS
1. enable
2.
configure terminal
3. spanning-tree mst instance-id priority priority
4.
end
DETAILED STEPS
Purpose Command or Action
Enables privileged EXEC mode. Enter your password if prompted. enable Step 1
Example:
Switch> enable
Enters the global configuration mode.
configure terminal
Example:
Switch# configure terminal
Step 2
Configures the switch priority. spanning-tree mst instance-id priority
priority Step 3
• 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.
Example:
Switch(config)# spanning-tree mst 0
priority 40960
• 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. These are the only acceptable values.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
270
How to Configure MSTP Features