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 bpduguard
spanning-tree bpduguard
To enable BPDU Guard on an interface, use the spanning-tree bpduguard command. To return to the
default settings, use the no form of this command.
spanning-tree bpduguard {enable | disable}
no spanning-tree bpduguard
Syntax Description
Command Default The setting that is already configured when you enter the spanning-tree port type edge bpduguard
default command.
Command Modes Interface configuration mode
Command History
Usage Guidelines BPDU Guard prevents a port from receiving BPDUs. If the port still receives a BPDU, it is put in the
error-disabled state as a protective measure.
Caution Be careful when using this command. You should use this command only with interfaces that connect to
end stations; otherwise, an accidental topology loop could cause a data-packet loop and disrupt the
switch and network operation.
When you enable this BPDU Guard command globally, the command applies only to spanning tree edge
ports. See spanning-tree port type edge bpduguard default for more information on the global
command for BPDU Guard. However, when you enable this feature on an interface, it applies to that
interface regardless of the spanning tree port type.
This command has three states:
• spanning-tree bpduguard enable—Unconditionally enables BPDU Guard on the interface.
• spanning-tree bpduguard disable—Unconditionally disables BPDU Guard on the interface.
• no spanning-tree bpduguard—Enables BPDU Guard on the interface if it is an operational
spanning tree edge port and if the spanning-tree port type edge bpduguard default command is
configured.
Typically, this feature is used in a service-provider environment where the network administrator wants
to prevent an access port from participating in the spanning tree.
enable Enables BPDU Guard on this interface.
disable Disables BPDU Guard on this interface.
Release Modification
4.0(0)N1(1a) This command was introduced.