Cisco Catalyst 4500 Series - Spanning-Tree Port-Priority

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
spanning-tree port-priority
spanning-tree port-priority
To prioritize an interface when two bridges compete for position as the root bridge, use the
spanning-tree port-priority command. The priority you set resolves the conflict. To revert to the
default setting, use the no form of this command.
spanning-tree port-priority port_priority
no spanning-tree port-priority
Syntax Description
Defaults Port priority value is set to 128.
Command Modes Interface configuration mode
Command History
Examples This example shows how to increase the possibility that the spanning-tree instance 20 will be chosen as
the root-bridge on interface FastEthernet 2/1:
Switch(config-if)# spanning-tree port-priority 0
Switch(config-if)#
Related Commands
port_priority Port priority; valid values are from 0 to 240 in increments of 16.
Release Modification
12.1(8a)EW Support for this command was introduced on the Catalyst 4500 series switch.
Command Description
spanning-tree cost Calculates the path cost of STP on an interface.
spanning-tree portfast default Enables PortFast by default on all access ports.
spanning-tree portfast (interface
configuration mode)
Enables PortFast mode.
spanning-tree uplinkfast Enables the UplinkFast feature.
spanning-tree vlan Configures STP on a per-VLAN basis.
show spanning-tree Displays spanning-tree state information.