Cisco Systems 3750E manual Configuring the Switch Priority of a Vlan, 18-21

Chapter 18 Configuring STP

Configuring Spanning-Tree Features

Note The show spanning-tree interface interface-idprivileged EXEC command displays information only for ports that are in a link-up operative state. Otherwise, you can use the show running-configprivileged EXEC command to confirm the configuration.

To return to the default setting, use the no spanning-tree[vlan vlan-id] cost interface configuration command. For information on how to configure load sharing on trunk ports by using spanning-tree path costs, see the “Configuring Trunk Ports for Load Sharing” section on page 13-24.

Configuring the Switch Priority of a VLAN

You can configure the switch priority and make it more likely that a standalone switch or a switch in the stack 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 vlan vlan-idroot primary and the spanning-tree vlan vlan-idroot secondary global configuration commands to modify the switch priority.

Beginning in privileged EXEC mode, follow these steps to configure the switch priority of a VLAN. This procedure is optional.

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	spanning-tree vlan vlan-idpriority priority	Configure the switch priority of a VLAN.
		• For vlan-id, you can specify a single VLAN identified by
		VLAN ID number, a range of VLANs separated by a
		hyphen, or a series of VLANs separated by a comma. The
		range is 1 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.
		Valid priority values are 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 vlan vlan-id	Verify your entries.
Step 5
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return to the default setting, use the no spanning-tree vlan vlan-idpriority global configuration command.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		18-21