Cisco Catalyst 4500 Series Configuration Manual page 1088

spanning-tree loopguard default
spanning-tree loopguard default
To enable loop guard as the default on all ports of a specific bridge, use the spanning-tree loopguard
default command. To disable loop guard, use the no form of this command.
Syntax Description
This command has no keywords or arguments.
Command Default Loop guard is disabled.
Command Modes Global configuration mode
Command History Release
12.1(12c)EW
Usage Guidelines Loop guard provides an additional security in the bridge network. Loop guard prevents alternate or root ports
from becoming the designated port because of a failure leading to a unidirectional link.
Loop guard operates only on ports that are considered point-to-point by the spanning tree.
Individual loop-guard port configuration overrides this global default.
Examples The following example shows how to enable loop guard:
Switch(config)# spanning-tree loopguard default
Switch(config)#
Related Commands Command
spanning-tree guard
show spanning-tree
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release XE 3.9.xE and 15.2(5)Ex
2-1038
spanning-tree loopguard default
no spanning-tree loopguard default
Modification
This command was introduced on the Catalyst 4500 series switch..
Description
Enables root guard.
Displays spanning-tree information.
Chapter 2