Cisco Nexus 5000 Series Command Reference Release 4.0(1a)N2(1) (OL-16599-01, March 2009)

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Cisco Nexus 5000 Series Command Reference
OL-16599-01
Chapter 2 Ethernet Commands
spanning-tree loopguard default
spanning-tree loopguard default
To enable Loop Guard as a default on all spanning tree normal and network ports, use the spanning-tree
loopguard default command. To disable Loop Guard, use the no form of this command.
spanning-tree loopguard default
no spanning-tree loopguard default
Syntax Description This command has no additional arguments or keywords.
Command Default Disabled.
Command Modes Configuration mode
Command History
Usage Guidelines Loop Guard provides additional security in the bridge network. Loop Guard prevents alternate or root
ports from becoming the designated port because of a failure that could lead to a unidirectional link.
Loop Guard operates only on ports that are considered point-to-point links by the spanning tree, and it
does not run on spanning tree edge ports.
Entering the Loop Guard command, spanning-tree guard loop, for the specified interface overrides this
global Loop Guard command.
Examples This example shows how to enable Loop Guard:
switch(config)# spanning-tree loopguard default
Related Commands
Release Modification
4.0(0)N1(1a) This command was introduced.
Command Description
show spanning-tree
summary
Displays information about the spanning tree state.