SecureStack C2 Configuration Guide 9-1
9
Spanning Tree Configuration
ThischapterdescribestheSpanningTreeConfigurationsetofcommandsandhowtousethem.
Spanning Tree Configuration Summary
Overview: Single, Rapid, and Multiple Spanning Tree Protocols
TheIEEE802.1DSpanningTreeProtocol(STP)resolvestheproblemsofphysicalloopsina
networkbyestablishingoneprimarypathbetweenanytwodevicesinanetwork.Anyduplicate
pathsarebarredfromuseandbecomestandbyorblockedpathsuntiltheoriginalpathfails,at
whichpointtheycan
bebroughtintoservice.
RSTP
TheIEEE802.1wRapidSpanningProtocol(RSTP),anevolutionof802.1D,canachievemuch
fasterconvergencethanlegacySTPinaproperlyconfigurednetwork.RSTPsignificantlyreduces
thetimetoreconfigurethenetwork’sactivetopologywhenphysicaltopology orconfiguration
parameterchangesoccur.Itselectsoneswitchastherootof
aSpanningTree‐connectedactive
topologyandassignsportrolestoindividualportsontheswitch,depend ingonwhetherthatport
ispartoftheactivetopology.
RSTPprovidesrapidconnectivityfollowingthefailureofaswitch,switchport,oraLAN.Anew
rootportandthedesignatedport
ontheothersideofthebridgetransitiontoforwardi ngthrough
anexplicithandshakebetweenthem.Bydefault,userportsareconfiguredtorapidlytransitionto
forwardinginRSTP.
MSTP
TheIEEE802.1sMultipleSpanningTreeProtocol(MSTP )buildsupon802.1DandRSTPby
optimizingutilizationofredundantlinksbetweenswitchesinanetwork.Whenredundantlinks
existbetweenapairofswitchesrunningsingleSTP,onelinkisforwardingwhilethe othersare
For information about... Refer to page...
Spanning Tree Configuration Summary 9-1
Configuring Spanning Tree Bridge Parameters 9-3
Configuring Spanning Tree Port Parameters 9-33
Configuring Spanning Tree Loop Protect Parameters 9-41
Caution: Spanning Tree configuration should be performed only by personnel who are very
knowledgeable about Spanning Trees and the configuration of the Spanning Tree Algorithm.
Otherwise, the proper operation of the network could be at risk.