Cisco Catalyst 3560X-24P Command Reference Manual page 862

spanning-tree mst root
When you enter the spanning-tree mst instance-id root secondary command, because of support for
the extended system ID, the software changes the switch priority from the default value (32768) to
28672. If the root switch fails, this switch becomes the next root switch (if the other switches in the
network use the default switch priority of 32768 and are therefore unlikely to become the root switch).
Examples
This example shows how to configure the switch as the root switch for instance 10 with a network
diameter of 4:
Switch(config)# spanning-tree mst 10 root primary diameter 4
This example shows how to configure the switch as the secondary root switch for instance 10 with a
network diameter of 4:
Switch(config)# spanning-tree mst 10 root secondary diameter 4
You can verify your settings by entering the show spanning-tree mst instance-id privileged EXEC
command.
Related Commands Command
show spanning-tree
spanning-tree mst forward-time
spanning-tree mst hello-time
spanning-tree mst max-age
spanning-tree mst max-hops
Catalyst 3750-X and 3560-X Switch Command Reference
2-830
Description
mst instance-id Displays MST information for the specified instance.
Sets the forward-delay time for all MST instances.
Sets the interval between hello BPDUs sent by root switch
configuration messages.
Sets the interval between messages that the spanning tree
receives from the root switch.
Sets the number of hops in a region before the BPDU is
discarded.
Chapter 2 Catalyst 3750-X and 3560-X Cisco IOS Commands
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