Spanning-Tree Bpduguard - Cisco Catalyst 4500 Series Command Reference Manual

Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches

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.
Syntax Description
enable
disable
Defaults
BPDU guard is disabled.
Command Modes
Interface configuration mode
Command History Release
12.1(12c)EW
Usage Guidelines
BPDU guard is a feature that prevents a port from receiving BPDUs. This feature is typically used in a
service provider environment where the administrator wants to prevent an access port from participating
in the spanning tree. If the port still receives a BPDU, it is put in the ErrDisable state as a protective
measure. This command has three states:
•
•
•
Examples
This example shows how to enable BPDU guard on this interface:
Switch(config-if)# spanning-tree bpduguard enable
Switch(config-if)#
Related Commands Command
show spanning-tree
spanning-tree portfast bpdufilter
default
OL-25342 -01
spanning-tree bpduguard {enable | disable}
no spanning-tree bpduguard
Enables BPDU guard on this interface.
Disables BPDU guard on this interface.
Modification
Support for this command was introduced on the Catalyst 4500 series switch.
spanning-tree bpduguard enable—This state unconditionally enables BPDU guard on the
interface.
spanning-tree bpduguard disable—This state unconditionally disables BPDU guard on the
interface.
no spanning-tree bpduguard—This state enables BPDU guard on the interface if it is in the
operational PortFast state and if the
configured.
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0SG and IOS 15.1(1)SG)
spanning-tree portfast bpduguard default
Description
Displays spanning-tree information.
Enables the BPDU filtering by default on all PortFast ports.
spanning-tree bpduguard
command is
2-939