Cisco Systems 3750E manual Revision version, Show pending, Exit, Spanning-tree mode mst, 19-17

Chapter 19 Configuring MSTP

Configuring MSTP Features

	Command	Purpose
Step 5
	revision version		Specify the configuration revision number. The range is 0 to 65535.
Step 6
	show pending		Verify your configuration by displaying the pending configuration.
Step 7
	exit		Apply all changes, and return to global configuration mode.
Step 8
	spanning-tree mode mst		Enable MSTP. RSTP is also enabled.
			Caution Changing spanning-tree modes can disrupt traffic because all
				spanning-tree instances are stopped for the previous mode and
				restarted in the new mode.
			You cannot run both MSTP and PVST+ or both MSTP and rapid PVST+
			at the same time.
Step 9
	end		Return to privileged EXEC mode.
Step 10
	show running-config		Verify your entries.
Step 11
	copy running-config startup-config		(Optional) Save your entries in the configuration file.

To return to the default MST region configuration, use the no spanning-tree mst configuration global configuration command. To return to the default VLAN-to-instance map, use the no instance instance-id[vlan vlan-range] MST configuration command. To return to the default name, use the no name MST configuration command. To return to the default revision number, use the no revision MST configuration command. To re-enable PVST+, use the no spanning-tree mode or the spanning-tree mode pvst global configuration command.

This example shows how to enter MST configuration mode, map VLANs 10 to 20 to MST instance 1, name the region region1, set the configuration revision to 1, display the pending configuration, apply the changes, and return to global configuration mode:

Switch(config)# spanning-tree mst configuration Switch(config-mst)#instance 1 vlan 10-20 Switch(config-mst)#name region1 Switch(config-mst)#revision 1 Switch(config-mst)#show pending

Pending MST configuration

Name [region1] Revision 1 Instance Vlans Mapped

-------- ---------------------

01-9,21-4094

110-20

-------------------------------

Switch(config-mst)# exit

Switch(config)#

Configuring the Root Switch

The switch maintains a spanning-tree instance for the group of VLANs mapped to it. A switch ID, consisting of the switch priority and the switch MAC address, is associated with each instance. For a group of VLANs, the switch with the lowest switch ID becomes the root switch.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		19-17