Specifications

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Catalyst 4500 Se ries S wit ch C is co IO S C om mand R efer ence —Re lease I OS XE 3 .3.0 XO(1 5.1 (1)XO)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
spanning-tree vlan
The spanning-tree root secondary command alters the switch bridge priority to 16384. If the root
switch fails, this switch becomes the next root switch.
Use the span ning- tree r oot comm ands on backbone switc hes only.
Examples This example shows how to enable spanning tree on VLAN 200:
Switch(config)# spanning-tree vlan 200
Switch(config)#
This example shows how to configure the switc h as the root switch for VLAN 10 with a network
diameter of 4:
Switch(config)# spanning-tree vlan 10 root primary diameter 4
Switch(config)#
This example shows how to configure the switc h as the secondary root sw itch for VLAN 10 with a
network diameter of 4:
Switch(config)# spanning-tree vlan 10 root secondary diameter 4
Switch(config)#
Related Commands Command Description
spanning-tree cost Calculates the path cost of STP on an interface.
spanning-tree port-priority Prioritizes an interface when two bridges compete for
position as the root bridge.
spanning-tree portfast default Enables PortFast by default on all access ports.
spanning- tree po rtfast (i nter face
configuration mode)
Enables PortFast mode.
spanning-tree vlan Config ures STP on a per-VLAN basis .
show spanning-tree Displays spanning-tree state information.