CISCO Routing and Bridging Configuration Guide

CorporateHeadquartersCiscoSystems,Inc.170WestTasmanDriveSanJose,CA95134-1706USA(6387)Fax:[phone]CiscoContentServicesSwitchRoutingandBridgingConfigurationGuideSoftwareVersion8.10November2005TextPartNumber:OL-8241-01THESPECIFICATIONSANDINFORMATIONREGARDINGTHEPRODUCTSINTHISMANUALARESUBJECTTOCHANGEWITHOUTNOTICE.ALLSTATEMENTS,INFORMATION,ANDRECOMMENDATIONSINTHISMANUALAREBELIEVEDTOBEACCURATEBUTAREPRESENTEDWITHOUTWARRANTYOFANYKIND,EXPRESSORIMPLIED.USERSMUSTTAKEFULLRESPONSIBILITYFORTHEIRAPPLICATIONOFANYPRODUCTS.THESOFTWARELICENSEANDLIMITEDWARRANTYFORTHEACCOMPANYINGPRODUCTARESETFORTHINTHEINFORMATIONPACKETTHATSHIPPEDWITHTHEPRODUCTANDAREINCORPORATEDHEREINBYTHISREFERENCE.IFYOUAREUNABLETOLOCATETHESOFTWARELICENSEORLIMITEDWARRANTY,CONTACTYOURCISCOREPRESENTATIVEFORACOPY.TheCiscoimplementationofTCPheadercompressionisanadaptationofaprogramdevelopedbytheUniversityofCalifornia,Berkeley(UCB)aspartofUCB’spublicdomainversionoftheUNIXoperatingsystem.Allrightsreserved.Copyright©1981,RegentsoftheUniversityofCalifornia.NOTWITHSTANDINGANYOTHERWARRANTYHEREIN,ALLDOCUMENTFILESANDSOFTWAREOFTHESESUPPLIERSAREPROVIDED“ASIS”WITHALLFAULTS.CISCOANDTHEABOVE-NAMEDSUPPLIERSDISCLAIMALLWARRANTIES,EXPRESSEDORIMPLIED,INCLUDING,WITHOUTLIMITATION,THOSEOFMERCHANTABILITY,FITNESSFORAPARTICULARPURPOSEANDNONINFRINGEMENTORARISINGFROMACOURSEOFDEALING,USAGE,ORTRADEPRACTICE.INNOEVENTSHALLCISCOORITSSUPPLIERSBELIABLEFORANYINDIRECT,SPECIAL,CONSEQUENTIAL,ORINCIDENTALDAMAGES,INCLUDING,WITHOUTLIMITATION,LOSTPROFITSORLOSSORDAMAGETODATAARISINGOUTOFTHEUSEORINABILITYTOUSETHISMANUAL,EVENIFCISCOORITSSUPPLIERSHAVEBEENADVISEDOFTHEPOSSIBILITYOFSUCHDAMAGES.CiscoContentServicesSwitchRoutingandBridgingConfigurationGuideCopyright©2005CiscoSystems,Inc.Allrightsreserved.CCSP,CCVP,theCiscoSquareBridgelogo,FollowMeBrowsing,andStackWisearetrademarksofCiscoSystems,Inc.;ChangingtheWayWeWork,Live,Play,andLearn,andiQuickStudyareservicemarksofCiscoSystems,Inc.;andAccessRegistrar,Aironet,ASIST,BPX,Catalyst,CCDA,CCDP,CCIE,CCIP,CCNA,CCNP,Cisco,theCiscoCertifiedInternetworkExpertlogo,CiscoIOS,CiscoPress,CiscoSystems,CiscoSystemsCapital,theCiscoSystemslogo,CiscoUnity,EmpoweringtheInternetGeneration,Enterprise/Solver,EtherChannel,EtherFast,EtherSwitch,FastStep,FormShare,GigaDrive,GigaStack,HomeLink,InternetQuotient,IOS,IP/TV,iQExpertise,theiQlogo,iQNetReadinessScorecard,LightStream,Linksys,MeetingPlace,MGX,theNetworkerslogo,NetworkingAcademy,NetworkRegistrar,Packet,PIX,Post-Routing,Pre-Routing,ProConnect,RateMUX,ScriptShare,SlideCast,SMARTnet,StrataViewPlus,TeleRouter,TheFastestWaytoIncreaseYourInternetQuotient,andTransPathareregisteredtrademarksofCiscoSystems,Inc.and/oritsaffiliatesintheUnitedStatesandcertainothercountries.AllothertrademarksmentionedinthisdocumentorWebsitearethepropertyoftheirrespectiveowners.TheuseofthewordpartnerdoesnotimplyapartnershiprelationshipbetweenCiscoandanyothercompany.(0502R)iiiCiscoContentServicesSwitchRoutingandBridgingConfigurationGuideOL-8241-01CONTENTSPrefacexvAudiencexviHowtoUseThisGuidexviRelatedDocumentationxviiSymbolsandConventionsxxObtainingDocumentationxxiCisco.comxxiProductDocumentationDVDxxiiOrderingDocumentationxxiiDocumentationFeedbackxxiiiCiscoProductSecurityOverviewxxiiiReportingSecurityProblemsinCiscoProductsxxivObtainingTechnicalAssistancexxivCiscoTechnicalSupport&DocumentationWebsitexxvSubmittingaServiceRequestxxvDefinitionsofServiceRequestSeverityxxviObtainingAdditionalPublicationsandInformationxxviiCHAPTER1ConfiguringInterfacesandCircuits1-1InterfaceandCircuitOverview1-1InterfaceandCircuitConfigurationQuickStart1-4ConfiguringInterfaces1-6ConfiguringanInterface1-7EnteringaDescriptionfortheInterface1-7ContentsivCiscoContentServicesSwitchRoutingandBridgingConfigurationGuideOL-8241-01ConfiguringInterfaceDuplexandSpeed1-8SettingInterfaceMaximumIdleTime1-10BridginganInterfacetoaVLAN1-11SpecifyingVLANTrunkingforanInterface1-12SelectingaDefaultVLANinaTrunk1-13ConfiguringSpanning-TreeBridgingforaVLANoraTrunkedInterface1-14ConfiguringSpanning-TreeBridgePathcost1-15ConfiguringSpanning-TreeBridgePortPriority1-15ConfiguringSpanning-TreeBridgeState1-16ConfiguringPortFastonanInterface1-16EnablingPortFast1-17EnablingBPDUGuard1-17ShowingPortFastInformation1-18ShowingInterfaceConfigurations1-19ShowingBridgeConfigurations1-19ShowingTrunkingConfigurations1-22ShowingInterfaceInformation1-22ShowingInterfaceDuplexandSpeed1-23ShowingInterfaceStatistics1-24ShowingEthernetInterfaceErrors1-27ShuttingDownanInterface1-29ShuttingDownAllInterfaces1-29RestartinganInterface1-30RestartingAllInterfaces1-30ConfiguringCircuits1-31EnteringCircuitConfigurationMode1-31ConfiguringaCircuitIPInterface1-31ConfiguringaCircuitIPAddress1-32ConfiguringaCircuit-IPBroadcastAddress1-32ConfiguringCircuit-IPRedirects1-33vCiscoContentServicesSwitchRoutingandBridgingConfigurationGuideOL-8241-01ContentsConfiguringCircuit-IPUnreachables1-33ConfiguringRouter-DiscoveryPreferenceforaCircuitIPInterface1-33EnablingandDisablingaCircuitIP1-34ConfiguringRouter