Cisco WS-C3560E-48PD-SF Command Reference - Page 626

spanning-tree mst root Chapter 2 Catalyst 3560 Switch Cisco IOS Commands 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 mst instance-id spanning-tree mst forward-time spanning-tree mst hello-time spanning-tree mst max-age spanning-tree mst max-hops Description 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. 2-594 Catalyst 3560 Switch Command Reference 78-16405-05