Cisco Systems RJ-45-to-AUX manual Assigning a Port Cost to a Port Using a CLI−Based Switch, 216

secondary (optional)	Used to designate the switch as a secondary root switch if the root bridge
	fails. The default priority of the secondary bridge is 16,384.
n (optional)	Specifies the VLAN. If you do not specify the VLAN, VLAN 1 is used.
	The valid value range is 1 through 1,005.
dia n (optional)	Specifies the diameter value discussed earlier in the chapter. It is
	essentially the number of bridges between any two points. The diameter
	should be measured starting from the root bridge. Valid values are 2
	through 7.
hello n (optional)	Specifies in seconds how often configuration messages should be
	generated by the root switch. The valid values are 1 through 10.

Setting the Root Bridge for More than One VLAN on a Set/Clear Command−Based Switch

To set the primary root switch for more than one VLAN on a Set/Clear−based switch, use the Privileged mode command to change configuration to a root bridge. The default priority automatically changes to 8,192, which is the default when the command is used to configure the switch as the root bridge. Use the following command to specify the root bridge:

set spantree root <rootsecondary> <VLAN list> dia <diameter>

The following command specifies the root bridge for VLANs 1 through 3:

set spantree root 1−3 dia 2

When the root bridge is configured correctly, the output on the console should be similar to this:

VLANs 1−3		bridge priority set		to 8192
VLANs 1−3		bridge max aging time			set to 10 seconds.
VLANS	1−3	bridge hello	time set		to	2 seconds.
VLANS	1−3	bridge forward delay set				to 7 seconds.
Switch is		now the root	switch	for active VLANs 1−3.

Assigning a Port Cost to a Port Using the Set/Clear Command−Based IOS

To manually change the port cost on a Set/Clear command−based switch, use the following Privileged mode command:

set spantree portcost <module/port> <port cost>

In the following example, 5 is the module number, 2 is the port number, and 100 is the configured port cost:

set spantree portcost 5/2 100

Assigning a Port Cost to a Port Using a CLI−Based Switch

To manually change the port cost on a Cisco IOS−based switch, use this Interface Configuration mode command:

spantree cost <port cost>

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