Specifications

clear spantree spanguard
9-26 Spanning Tree Configuration
Mode
Switchcommand,read‐write.
Usage
SpanGuardisdesignedtodisable,orlockoutan“edge”portwhenanunexpectedBPDUis
received.Theportcanbeconfiguredtobere‐enabledafterasettimeperiod,oronlyaftermanual
intervention.
Aportcanbedefinedasanedge(user)portusingthesetspantreeadminedge
command,
describedin“setspantreeadminedge”onpage 9‐39.Aportdesignatedasanedgeportis
expectedtobeconnectedtoaworkstationorotherend‐usertypeofdevice,andnottoanother
switchinthenetwork.WhenSpanGuardisenabled,ifanon‐loopbackBPDUis
receivedonan
edgeport,theSpanningTreestateofthatportwillbechangedto“blocking”andwillnolonger
forwardtraffic.Theportwillremaindisableduntiltheamountoftimedefinedbysetspantree
spanguardtimeout(“setspantreespanguardtimeout”onpage 9‐27)haspassedsincethelastseen

BPDU,theportismanuallyunlocked(setorclearspantreespanguardlock,“clear/setspantree
spanguardlock”onpage 9‐29),theconfigurationoftheportischangedsoitisnotlongeranedge
port,ortheSpanGuardfunctionisdisabled.
SpanGuardisenabledanddisabledonlyonaglobal
basis(acrossthestack,ifapplicable).By
default,SpanGuardisdisabledandSpanGuardtrapsareenabled.
Example
ThisexampleshowshowtoenabletheSpanGuardfunction:
B2(rw)->set spantree spanguard enable
clear spantree spanguard
UsethiscommandtoresetthestatusoftheSpanningTreeSpanGuardfunctiontodisabled.
Syntax
clear spantree spanguard
Parameters
None.
Defaults
None.
Mode
Switchcommand,read‐write.
Example
ThisexampleshowshowtoresetthestatusoftheSpanGuardfunctiontodisabled:
B2(rw)->clear spantree spanguard