C613-50170-01 Rev B
Command Reference for x510 Series
691
AlliedWare Plus™ Operating System - Version 5.4.7-1.x
S
PANNING
T
REE
C
OMMANDS
SPANNING
-
TREE
PORTFAST
BPDU
-
GUARD
spanning-tree portfast bpdu-guard
Overview
This command applies a BPDU (Bridge Protocol Data Unit) guard to the port. A port
with the bpdu-guard feature enabled will block all traffic (BPDUs and user data), if
it starts receiving BPDUs.
Use this command in Global Configuration mode to apply BPDU guard to all ports
on the device. Use this command in Interface mode for an individual interface or a
range of interfaces specified. BPDU Guard is not enabled on a port by default.
Use the
no
variant of this command to disable the BPDU Guard feature on a device
in Global Configuration mode or to disable the BPDU Guard feature on a port in
Interface mode.
Syntax (Global
Configuration)
spanning-tree portfast bpdu-guard
no spanning-tree portfast bpdu-guard
Syntax (Interface
Configuration)
spanning-tree portfast bpdu-guard {default|disable|enable}
no spanning-tree portfast bpdu-guard
Default
BPDU Guard is not enabled on any ports by default.
Mode
Global Configuration or Interface Configuration
Usage
This command blocks the port(s) to all devices and data when enabled. BPDU
Guard is a port-security feature that changes how a portfast-enabled port behaves
if it receives a BPDU. When
bpdu-guard
is set, then the port shuts down if it
receives a BPDU. It does not process the BPDU as it is considered suspicious. When
bpdu-guard
is not set, then the port will negotiate spanning-tree with the device
sending the BPDUs. By default, bpdu- guard is not enabled on a port.
You can configure a port disabled by the bpdu-guard to re-enable itself after a
specific time interval. This interval is set with the
spanning-tree errdisable-timeout
command. If you do not use the
errdisable-timeout
feature, then you will
need to manually re-enable the port by using the
no shutdown
command.
Parameter
Description
bpdu-guard
A port that has bpdu-guard turned on will enter the STP blocking state
if it receives a BPDU. This port type has one of the following
parameters (in Interface Configuration mode):
default
Takes the setting that has been configured for the whole
device, i.e. the setting made from the Global configuration
mode.
disable
Turns off BPDU guard.
enable
Turns on BPDU guard and will also set the port as an edge
port.