configuring_cisco_stackwise_virtual.pdf

cisco

1. ConfiguringCiscoStackWiseVirtual
•FindingFeatureInformation,onpage1
•PrerequisitesforCiscoStackWiseVirtual,onpage1
•RestrictionsforCiscoStackWiseVirtual,onpage2
•InformationAboutCiscoStackWiseVirtual,onpage3
•HowtoConfigureCiscoStackWiseVirtual,onpage13
•VerifyingCiscoStackWiseVirtualConfiguration,onpage21
•AdditionalReferencesforStackWiseVirtual,onpage22
•FeatureHistoryforCiscoStackWiseVirtual,onpage22
FindingFeatureInformation
Yoursoftwarereleasemaynotsupportallthefeaturesdocumentedinthismodule.Forthelatestcaveatsand
featureinformation,seeBugSearchToolandthereleasenotesforyourplatformandsoftwarerelease.To
findinformationaboutthefeaturesdocumentedinthismodule,andtoseealistofthereleasesinwhicheach
featureissupported,seethefeatureinformationtableattheendofthismodule.
UseCiscoFeatureNavigatortofindinformationaboutplatformsupportandCiscosoftwareimagesupport.
ToaccessCiscoFeatureNavigator,gotohttps://cfnng.cisco.com/.AnaccountonCisco.comisnotrequired.
PrerequisitesforCiscoStackWiseVirtual
•BothswitchesintheCiscoStackWiseVirtualpairmustbedirectlyconnectedtoeachother.
•BothswitchesintheCiscoStackWiseVirtualpairmustbeofthesameswitchmodel.
•BothswitchesintheCiscoStackWiseVirtualpairmustberunningthesamelicenselevel.
•BothswitchesintheCiscoStackWiseVirtualpairmustberunningthesamesoftwareversion.
•BothswitchesintheCiscoStackWiseVirtualpairmustberunningthesameSDMtemplate.
•AlltheportsusedforconfiguringaStackWiseVirtualLink(SVL)mustsharethesamespeed.For
example,youcannotconfigurea10Gora40GporttoformanSVL,simultaneously.
ConfiguringCiscoStackWiseVirtual
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2. WhenyouenableCiscoStackWiseVirtualonthedevice:
•Layer2,Layer3,Security,QualityofService,Multicast,Application,MonitoringandManagement,
MultiprotocolLabelSwitching,andHighAvailabilityaresupported.ContacttheCiscoTechnicalSupport
Centreforthespecificlistoffeaturesthataresupportedundereachoneofthesetechnologies.
•ResilientEthernetProtocol,RemoteSwitchedPortAnalyzer,andSofware-DefinedAccessareNOT
supported.
Note
RestrictionsforCiscoStackWiseVirtual
CommonRestrictionsforCiscoCatalyst9500and9500HighPerformanceSeriesSwitches
Thefollowingaretherestrictionscommontoalltheswitches:
•TheFederalInformationProcessingStandards(FIPS)isnotsupportedonSVLs;usingFIPScommands
inreleasesthatdonotsupportFIPSwillresultinnondeterministicbehavior.
•WhendeployingCiscoStackWiseVirtual,ensurethatVLANID4094isnotusedanywhereonthe
network.Allinter-chassissystemcontrolcommunicationbetweenstackmembersiscarriedoverthe
reservedVLANID4094fromtheglobalrange.
•Dual-ActiveDetection(DAD)andSVLconfigurationmustbeperformedmanuallyandthedevices
shouldberebootedfortheconfigurationchangestotakeeffect.
•CiscoStackWiseVirtualconfigurationcommandswillberecognisedonlyonaswitchrunningNetwork
Advantagelicense.TheconfigurationcommandswillnotberecognisedonaNetworkEssentialslicense.
•OnlyCiscoTransceiverModulesaresupported.
•TheinterfaceVLANMACaddressthatisassignedbydefault,canbeoverriddenusingthemac-address
command.IfthiscommandisconfiguredonasingleSVIorrouterportthatrequiresLayer3injected
packets,allotherSVIsorroutedportsonthedevicealsomustbeconfiguredwiththesamefirstfour
mostsignificantbytes(4MSB)oftheMACaddress.Forexample,ifyousettheMACaddressofany
SVItoxxxx.yyyy.zzzz,settheMACaddressofallotherSVIstostartwithxxxx.yyyy.IfLayer3injected
packetsarenotused,thisrestrictiondoesnotapply.
ThisappliestoallLayer3ports,SVIs,androutedports.Thisdoesnotapplyto
GigabitEthernet0/0port.
Note
RestrictionsforCiscoCatalyst9500SeriesSwitches
•WhenconfiguringStackWiseVirtuallinks(SVLs)on9500-40XandC9500-16XmodelsoftheCisco
Catalyst9500SeriesSwitches,notethatyoucannotcreateSVLsonanyofthenetworkmodules.
•4x10GbreakoutcablesarenotsupportedwithSVLmode.
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ConfiguringCiscoStackWiseVirtual
RestrictionsforCiscoStackWiseVirtual

3. RestrictionsforCiscoCatalyst9500SeriesHighPerformanceSwitches
•4x25Gand4x10GbreakoutcablesarenotsupportedwithSVLmode.
•OnC9500-32Cswitches,youcanconfigureSVLandDADonlyoninterfacesnumbered1-16onthe
frontpaneloftheswitch.
•OnC9500-32QC,youcanconfigureSVLandDADonlyonnative100Gand40Ginterfaces(default
configurationports).YoucannotconfigureSVLandDADonconverted100Gand40Ginterfaces.
•OnCiscoCatalyst9500SeriesHighPerformanceSwitches,configuringSVLusing1Ginterfacesisnot
supported.
InformationAboutCiscoStackWiseVirtual
CiscoStackWiseVirtualonCiscoCatalyst9500SeriesSwitches
ThissectiondescribestheCiscoStackWiseVirtualfeaturesspecifictoCiscoCatalyst9500SeriesSwitches
andCiscoCatalyst9500SeriesHighPerformanceSwitches.
•CiscoStackWiseVirtualissupportedonthefollowingmodels:
Table1:SwitchessupportingStackWiseVirtual
CiscoCatalyst9500SeriesHighPerformance
Switches
CiscoCatalyst9500SeriesSwitches
C9500-32CC9500-24Q
C9500-32QCC9500-12Q
C9500-24Y4CC9500-40X
C9500-48Y4CC9500-16X
•YoucanestablishSVLsusing40Gor10GEthernetconnections(downlinkconnections)onCiscoCatalyst
9500SeriesSwitchesand100G,40G,25Gand10GEthernetconnectionsonCiscoCatalyst9500Series
HighPerformanceSwitches.
•Youcanconfigureupto8SVLsinaCiscoStackWiseVirtualsolutionusingCiscoCatalyst9500Series
SwitchesorCiscoCatalyst9500SeriesHighPerformanceSwitches.
StackWiseVirtualOverview
CiscoStackWiseVirtualisanetworksystemvirtualizationtechnologythatpairstwoswitchesintoonevirtual
switch.SwitchesinaCiscoStackWiseVirtualsolutionincreaseoperationalefficiencybyusingsinglecontrol
andmanagementplane,scalesystembandwidthwithdistributedforwardingplane,andassistinbuilding
resilientnetworksusingtherecommendednetworkdesign.CiscoStackWiseVirtualallowstwophysical
switchestooperateasasinglelogicalvirtualswitchusinganEthernetconnection.
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ConfiguringCiscoStackWiseVirtual
InformationAboutCiscoStackWiseVirtual

4. CiscoStackWiseVirtualTopology
Atypicalnetworkdesignconsistsofcore,distribution,andaccesslayers.Thedefaultmodeofaswitchis
standalone.Whentworedundantswitchesaredeployedinthedistributionlayer,thefollowingnetwork
challengesarise:
•IfVLANIDsarereusedbetweenaccesslayersthen,itwillintroduceaspanningtreeloopthatwillimpact
theoverallperformanceofthenetwork.
•SpanningtreeprotocolsandconfigurationarerequiredtoprotectLayer2networkagainstspanningtree
protocolloop,androotandbridgeprotocoldataunitmanagement.
•AdditionalprotocolssuchasfirsthopredundancyprotocolarerequiredtovirtualizetheIPgateway
function.ThisshouldalignwithSTProotprioritiesforeachVLAN.
•TheProtocolindependentmulticastdesignatedrouter(PIMDR)configurationshouldbefine-tunedto
selectivelybuildamulticastforwardingtopologyonaVLAN.
•Thestandalonedistributionlayersystemprovidesprotocol-drivenremotefailureanddetection,which
resultsinslowerconvergencetime.Fine-tuneFHRPandPIMtimersforrapidfaultdetectionandrecovery
process.
WerecommendCiscoStackWiseVirtualmodelforaggregationlayersandcollapsedaggregationandcore
layers.Thestackcanbeformedoveraredundant100G,25G,40Gor10Gfiberlinkstoensurethatthe
distributionortheaggregationswitchescanbedeployedoveralargedistance.
NotethatSTPkeepsoneoftheportsconnectedtothedistributionswitchesblockedontheaccessswitches.
Asaresultofthis,anactivelinkfailurecausesSTPconvergenceandthenetworksuffersfromtrafficloss,
flooding,andapossibletransientloopinthenetwork.Ontheotherhand,iftheswitchesarelogicallymerged
intooneswitch,alltheaccessswitchesmightformanEtherChannelbundlewithdistributionswitches,and
alinkfailurewithinanEtherChannelwouldnothaveanyimpactaslongasatleastonememberwithinthe
EtherChannelisactive.
Figure1:TypicalNetworkDesignusingCiscoStackWiseVirtual
EtherchannelinStackWiseVirtualiscapableofimplementingMulti-chassisEtherChannel(MEC)acrossthe
stackmembers.WhenaccesslayerandaggregationlayerarecollapsedintoasingleStackWiseVirtualsystem,
MECacrossthedifferentaccesslayerdomainmembersandacrossdistributionandaccesslayerswitcheswill
notbesupported.MECisdesignedtoforwardthetrafficoverthelocallinkirrespectiveofthehashresult.
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CiscoStackWiseVirtualTopology

5. Sincethecontrolplane,managementplane,anddataplaneareintegrated,thesystembehavesasasingle
switch.
Thevirtualizationofmultiplephysicalswitchesintoasinglelogicalswitchisfromacontrolandmanagement
planeperspectiveonly.Becauseofthecontrolplanebeingcommon,itmaylooklikeasinglelogicalentity
topeerswitches.Thedataplaneoftheswitchesisdistributed.Eachswitchiscapableofforwardingoverits
localinterfaceswithoutinvolvingothermembers.However,whenapacketcomingintoaswitchhastobe
forwardedoveradifferentmember’sport,theforwardingcontextofthepacketiscarriedovertothedestination
switchafteringressprocessingisperformedintheingressswitch.Egressprocessingisdoneonlyintheegress
switch.Thisprovidesauniformdataplanebehaviortotheentireswitchirrespectivewhetherofthedestination
portisinalocalswitchorinaremoteswitch.However,thecommoncontrolplaneensuresthatalltheswitches
haveequivalentdataplaneentryforeachforwardingentity.
AnelectionmechanismelectsoneoftheswitchestobeCiscoStackWiseVirtualactiveandtheotherswitch
tobeCiscoStackWiseVirtualstandbyintermsofControlPlanefunctions.Theactiveswitchisresponsible
forallthemanagement,bridgingandroutingprotocols,andsoftwaredatapath.Thestandbyswitchisinhot
standbystatereadytotakeovertheroleofactive,iftheactiveswitchfailsover.
ThefollowingarethecomponentsoftheCiscoStackWiseVirtualsolution:
•Stackmembers
•StackWiseVirtuallink:100G,25G,40Gor10GEthernetconnections.SVLisestablishedusingthe
100G,25G,40Gor10Ginterfacesdependingontheswitchmodels.However,acombinationoftwo
differentspeedsisnotsupported.
StackWiseVirtuallinkisthelinkthatconnectstheswitchesoverEthernet.Typically,CiscoStackWiseVirtual
consistsofmultiple100G,25G,40Gor10Gphysicallinks.Itcarriesallthecontrolanddatatrafficbetween
theswitchingunits.YoucanconfigureaStackWiseVirtuallinkonasupportedport.Whenaswitchispowered
upandthehardwareisinitialized,itlooksforaconfiguredStackWiseVirtuallinkbeforetheinitializationof
thecontrolplane.
TheLinkManagementProtocol(LMP)isactivatedoneachlinkoftheStackWiseVirtuallinksassoonasthe
linksareestablished.LMPensuretheintegrityofSVLlinksandmonitorsandmaintainsthehealthofthe
links.TheredundancyroleofeachswitchisresolvedbytheStackWiseDiscoveryProtocol(SDP).Itensures
thatthehardwareandsoftwareversionsarecompatibletoformtheSVLanddetermineswhichswitchbecomes
activeorstandbyfromacontrolplaneperspective.
CiscoStackWiseVirtualHeader(SVH)is64-byteframeheaderthatisprependedoverallcontrol,data,and
managementplanetrafficthattraverseovereachSVLbetweenthetwostackmembersoftheCiscoStackWise
Virtualdomain.TheSVH-encapsulatedtrafficoperatesatOSILayer2andcanberecognizedandprocessed
onlybyCiscoStackWiseVirtual-enabledswitches.SVLinterfacesarenon-bridgeableandnon-routeable,
andallowsnon-routeabletrafficoverL2orL3network.
CiscoStackWiseVirtualRedundancy
CiscoStackWiseVirtualoperatesstatefulswitchover(SSO)betweentheactiveandstandbyswitches.The
followingarethewaysinwhichCiscoStackWiseVirtual'sredundancymodeldiffersfromthatofthestandalone
mode:
•TheCiscoStackWiseVirtualactiveandstandbyswitchesarehostedinseparateswitchesandusea
StackWiseVirtuallinktoexchangeinformation.
•TheactiveswitchcontrolsboththeswitchesofCiscoStackWiseVirtual.Theactiveswitchrunsthe
Layer2andLayer3controlprotocolsandmanagestheswitchingmodulesofboththeswitches.
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CiscoStackWiseVirtualRedundancy

6. •TheCiscoStackWiseVirtualactiveandstandbyswitchesperformdatatrafficforwarding.
IftheCiscoStackWiseVirtualactiveswitchfails,thestandbyswitchinitiatesaswitchoverandassumesthe
CiscoStackWiseVirtualactiveswitchrole.
Note
SSORedundancy
AStackWiseVirtualsystemoperateswithSSOredundancyifitmeetsthefollowingrequirements:
•Boththeswitchesmustberunningthesamesoftwareversion,unlesstheyareintheprocessofsoftware
upgrade.
•StackWiseVirtuallink-relatedconfigurationinthetwoswitchesmustmatch.
•Licensetypemustbesameonboththeswitchmodels.
•BoththeswitchmodelsmustbeinthesameStackWiseVirtualdomain.
WithSSOredundancy,theStackWiseVirtualstandbyswitchisalwaysreadytoassumecontrolifafault
occursontheStackWiseVirtualactiveswitch.Configuration,forwarding,andstateinformationare
synchronizedfromtheStackWiseVirtualactiveswitchtotheredundantswitchatstartup,andwhenever
changestotheStackWiseVirtualactiveswitchconfigurationoccur.Ifaswitchoveroccurs,trafficdisruption
isminimized.
IfStackWiseVirtualdoesnotmeettherequirementsforSSOredundancy,itwillbeincapableofestablishing
arelationshipwiththepeerswitch.StackWiseVirtualrunsstatefulswitchover(SSO)betweentheStackWise
Virtualactiveandstandbyswitches.TheStackWiseVirtualdeterminestheroleofeachswitchduring
initialization.
TheCPUintheStackWiseVirtualstandbyswitchrunsinhotstandbystate.StackWiseVirtualusesaStackWise
VirtuallinktosynchronizeconfigurationdatafromtheStackWiseVirtualactiveswitchtotheStackWise
Virtualstandbyswitch.Also,protocolsandfeaturesthatsupporthighavailabilitysynchronizetheirevents
andstateinformationtotheStackWiseVirtualstandbyswitch.
NonstopForwarding
WhileimplementingNonstopForwarding(NSF)technologyinsystemsusingSSOredundancymode,network
disruptionsareminimizedforcampususersandapplications.Highavailabilityisprovidedevenwhenthe
control-planeprocessingstack-memberswitchisreset.DuringafailureoftheunderlyingLayer3,NSF-capable
protocolsperformgracefulnetworktopologyresynchronization.Thepresetforwardinginformationonthe
redundantstack-memberswitchremainsintact;thisswitchcontinuestoforwardthedatainthenetwork.This
serviceavailabilitysignificantlylowersthemeantimetorepair(MTTR)andincreasesthemeantimebetween
failure(MTBF)toachieveahighlevelofnetworkavailability.
MultichassisEtherChannels
MultichassisEtherChannel(MEC)isanEtherChannelbundledwithphysicalportshavingcommon
characteristicssuchasspeedandduplex,thataredistributedacrosseachCiscoStackWiseVirtualsystem.A
CiscoStackWiseVirtualMECcanconnecttoanynetworkelementthatsupportsEtherChannel(suchasa
host,server,router,orswitch).CiscoStackWiseVirtualsupportsupto128MECsdeployedinLayer2or
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SSORedundancy

7. Layer3modes.EtherChannel127and128arereservedforSVLconnections.Hence,themaximumavailable
MECcountis126.
InaCiscoStackWiseVirtualsystem,anMECisanEtherChannelwithadditionalcapability.Amultichassis
EtherChannellinkreducestheamountoftrafficthatrequirestransmissionacrosstheStackWiseVirtuallink
bypopulatingtheindexportonlywiththeportslocaltothephysicalswitch.Thisallowstheswitchtogive
precedencetothelocalportsofthemultichassisEtherChannellinkoverthoseontheremoteswitch.
EachMECcanoptionallybeconfiguredtosupporteitherCiscoPAgP,IEEELACP,orStaticONmode.We
recommendthatyouimplementEtherChannelusingCiscoPAgPorLACPwithacompatibleneighbor.Ifa
remotelyconnectedneighborsuchasCiscoWirelessLANController(WLC)doesnotsupportthislink-bundling
protocol,thenaStaticONmodecanbedeployed.TheseprotocolsrunonlyontheCiscoStackWiseVirtual
activeswitch.
AnMECcansupportuptoeightphysicallinksthatcanbedistributedinanyproportionbetweentheCisco
StackWiseVirtualactiveswitchandtheCiscoStackWiseVirtualstandbyswitch.Werecommendthatyou
distributetheMECportsacrossbothswitchesevenly.
MECMinimumLatencyLoadBalancing
TheStackWiseVirtualenvironmentisdesignedsuchthatdataforwardingalwaysremainswithintheswitch.
TheVirtualStackalwaystriestoforwardtrafficonthelocallyavailablelinks.ThisistrueforbothLayer2
andLayer3links.Theprimarymotivationforlocalforwardingistoavoidunnecessarilysendingdatatraffic
overtheStackWiseVirtuallinkandthusreducethelatency(extrahopovertheSVL)andcongestion.The
bidirectionaltrafficisload-sharedbetweenthetwoStackWiseVirtualmembers.However,foreachStackWise
Virtualmember,ingressandegresstrafficforwardingisbasedonlocally-attachedlinksthatarepartofMEC.
ThislocalforwardingisakeyconceptinunderstandingconvergenceandfaultconditionsinaStackWise
Virtualenabledcampusnetwork.
Theactiveandstandbyswitchessupportlocalforwardingthatwillindividuallyperformthedesiredlookups
andforwardthetrafficonlocallinkstouplinkneighbors.IfthedestinationisaremoteswitchintheStackWise
Virtualdomain,ingressprocessingisperformedontheingressswitchandthentrafficisforwardedoverthe
StackWiseVirtuallinktotheegressswitchwhereonlyegressprocessingisperformed.
MECFailureScenarios
WerecommendthatyouconfigureaMECwithatleastonelinktoeachswitch.Thisconfigurationensures
thatthereisalwaysanalternatepathfordatatrafficincaseofaswitchfailure.
Thefollowingsectionsdescribeissuesthatmayariseandtheresultingimpact:
SingleMECLinkFailure
IfalinkwithinaMECfails(andotherlinksintheMECarestilloperational),theMECredistributestheload
amongtheoperationallinks,asinaregularport.
AllMECLinkstotheCiscoStackWiseVirtualActiveSwitchFail
IfallthelinkstotheCiscoStackWiseVirtualactiveswitchfail,aMECbecomesaregularEtherChannelwith
operationallinkstotheCiscoStackWiseVirtualstandbyswitch.
DatatrafficthatterminatesontheCiscoStackWiseVirtualactiveswitchreachestheMECbycrossinga
StackWiseVirtuallinktotheCiscoStackWiseVirtualstandbyswitch.Controlprotocolscontinuetorunin
theCiscoStackWiseVirtualactiveswitch.ProtocolmessagesreachtheMECbycrossingaStackWiseVirtual
link.
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MECMinimumLatencyLoadBalancing

8. AllMECLinksFail
IfallthelinksinanMECfail,thelogicalinterfacefortheEtherChannelissettoUnavailable.Layer2control
protocolsperformthesamecorrectiveactionasforalink-downeventonaregularEtherChannel.
Onadjacentswitches,routingprotocolsandtheSpanningTreeProtocol(STP)performthesamecorrective
actionasforaregularEtherChannel.
CiscoStackWiseVirtualStandbySwitchFailure
IftheCiscoStackWiseVirtualstandbyswitchfails,aMECbecomesaregularEtherChannelwithoperational
linksontheCiscoStackWiseVirtualactiveswitch.Connectedpeerswitchesdetectthelinkfailures,and
adjusttheirload-balancingalgorithmstouseonlythelinkstotheStackWiseVirtualactiveswitch.
CiscoStackWiseVirtualActiveSwitchFailure
CiscoStackWiseVirtualactiveswitchfailureresultsinastatefulswitchover(SSO).Aftertheswitchover,a
MECisoperationalonthenewCiscoStackWiseVirtualactiveswitch.Connectedpeerswitchesdetectthe
linkfailures(tothefailedswitch),andadjusttheirload-balancingalgorithmstouseonlythelinkstothenew
CiscoStackWiseVirtualactiveswitch.
CiscoStackWiseVirtualPacketHandling
InCiscoStackWiseVirtual,theCiscoStackWiseVirtualactiveswitchrunstheLayer2andLayer3protocols
andfeaturesandmanagestheportsonboththeswitches.
CiscoStackWiseVirtualusesStackWiseVirtuallinktocommunicatesystemandprotocolinformationbetween
thepeerswitchesandtocarrydatatrafficbetweenthetwoswitches.
ThefollowingsectionsdescribepackethandlinginCiscoStackWiseVirtual.
TrafficonaStackWiseVirtuallink
AStackWiseVirtuallinkcarriesdatatrafficandin-bandcontroltrafficbetweentwoswitches.Alltheframes
thatareforwardedovertheStackWiseVirtuallinkareencapsulatedwithaspecialStackWiseVirtualHeader
(SVH).TheSVHaddsanoverheadof64bytesforcontrolanddatatraffic,whichprovidesinformationfor
CiscoStackWiseVirtualtoforwardthepacketonthepeerswitch.
AStackWiseVirtuallinktransportscontrolmessagesbetweentwoswitches.Messagesincludeprotocol
messagesthatareprocessedbytheCiscoStackWiseVirtualactiveswitch,butreceivedortransmittedby
interfacesontheCiscoStackWiseVirtualstandbyswitch.Controltrafficalsoincludesmoduleprogramming
betweentheCiscoStackWiseVirtualactiveswitchandtheswitchingmodulesontheCiscoStackWiseVirtual
standbyswitch.
CiscoStackWiseVirtualtransmitsdatatrafficoveraStackWiseVirtuallinkunderthefollowingcircumstances:
•Layer2trafficfloodedoveraVLAN(evenfordual-homedlinks).
•PacketsprocessedbysoftwareontheCiscoStackWiseVirtualactiveswitchwheretheingressinterface
isontheCiscoStackWiseVirtualstandbyswitch.
•Thepacketdestinationisonthepeerswitch,asdescribedinthefollowingexamples:
•TrafficwithinaVLANwheretheknowndestinationinterfaceisonthepeerswitch.
•Trafficthatisreplicatedforamulticastgroupandthemulticastreceiversareonthepeerswitch.
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CiscoStackWiseVirtualPacketHandling

9. •TheknownunicastdestinationMACaddressisonthepeerswitch.
•ThepacketisaMACnotificationframedestinedforaportonthepeerswitch.
AStackWiseVirtuallinkalsotransportssystemdata,suchasNetFlowexportdataandSNMPdata,fromthe
CiscoStackWiseVirtualstandbyswitchtotheCiscoStackWiseVirtualactiveswitch.
TrafficontheStackWiseVirtuallinkisloadbalancedwiththesameglobalhashingalgorithmsavailablefor
EtherChannels(thedefaultalgorithmissource-destinationIP).
Layer2Protocols
TheCiscoStackWiseVirtualactiveswitchrunstheLayer2protocols(suchasSTPandVTP)fortheswitching
modulesonboththeswitches.Protocolmessagesthatarereceivedonthestandbyswitchportsmusttraverse
SVLlinkstoreachtheactiveswitchwheretheyareprocessed.Similarly,protocolmessagesthataretransmitted
fromthestandbyswitchportsoriginateontheactiveswitch,andtraversetheSVLlinkstoreachthestandby
ports.
AlltheLayer2protocolsinCiscoStackWiseVirtualworksimilarlyinstandalonemode.Thefollowing
sectionsdescribethedifferenceinbehaviorforsomeprotocolsinCiscoStackWiseVirtual.
SpanningTreeProtocol
TheCiscoStackWiseVirtualactiveswitchrunstheSTP.TheCiscoStackWiseVirtualstandbyswitchredirects
theSTPBPDUsacrossaStackWiseVirtuallinktotheStackWiseVirtualactiveswitch.
TheSTPbridgeIDiscommonlyderivedfromtheswitchMACaddress.ToensurethatthebridgeIDdoes
notchangeafteraswitchover,CiscoStackWiseVirtualcontinuestousetheoriginalswitchMACaddressfor
theSTPBridgeID.
EtherChannelControlProtocols
LinkAggregationControlProtocol(LACP)andPortAggregationProtocol(PAgP)packetscontainadevice
identifier.CiscoStackWiseVirtualdefinesacommondeviceidentifierforboththeswitches.UseeitherPAgP
orLACPonMultiEtherChannelsinsteadofmodeON,evenifallthethreemodesaresupported.
AnewPAgPenhancementhasbeendefinedforassistingwithdual-activescenariodetection.Note
SwitchedPortAnalyzer
SwitchedPortAnalyzer(SPAN)onStackWiseVirtuallinkportsisnotsupported;SVLportscanbeneither
aSPANsource,noraSPANdestination.CiscoStackWiseVirtualsupportsalltheSPANfeaturesfornon-SVL
interfaces.ThenumberofSPANsessionsthatareavailableonCiscoStackWiseVirtualmatchesthatona
singleswitchrunninginstandalonemode.
PrivateVLANs
PrivateVLANsonStackWiseVirtualworkthesamewayasinstandalonemode.Theonlyexceptionisthat
thenativeVLANonisolatedtrunkportsmustbeconfiguredexplicitly.
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Layer2Protocols

10. ApartfromSTP,EtherChannelControlProtocols,SPAN,andprivateVLANs,theDynamicTrunkingProtocol
(DTP),CiscoDiscoveryProtocol(CDP),VLANTrunkProtocol(VTP),andUnidirectionalLinkDetection
Protocol(UDLD)aretheadditionalLayer2control-planeprotocolsthatrunovertheSVLconnections.
Layer3Protocols
TheCiscoStackWiseVirtualactiveswitchrunstheLayer3protocolsandfeaturesfortheStackWiseVirtual.
AlltheLayer3protocolpacketsaresenttoandprocessedbytheCiscoStackWiseVirtualactiveswitch.Both
thememberswitchesperformhardwareforwardingforingresstrafficontheirinterfaces.Whensoftware
forwardingisrequired,packetsaresenttotheCiscoStackWiseVirtualactiveswitchforprocessing.
ThesamerouterMACaddressassignedbytheCiscoStackWiseVirtualactiveswitchisusedforalltheLayer
3interfacesonboththeCiscoStackWiseVirtualmemberswitches.Afteraswitchover,theoriginalrouter
MACaddressisstillused.TherouterMACaddressischosenbasedonchassis-macandispreservedafter
switchoverbydefault.CiscoCatalyst9500SeriesHighPerformanceswitchessupportLayer3subinterfaces.
ThefollowingsectionsdescribetheLayer3protocolsforCiscoStackWiseVirtual.
IPv4Unicast
TheCPUontheCiscoStackWiseVirtualactiveswitchrunstheIPv4routingprotocolsandperformsany
requiredsoftwareforwarding.AlltheroutingprotocolpacketsreceivedontheCiscoStackWiseVirtualstandby
switchareredirectedtotheCiscoStackWiseVirtualactiveswitchacrosstheStackWiseVirtuallink.The
CiscoStackWiseVirtualactiveswitchgeneratesalltheroutingprotocolpacketstobesentoutoverportson
eitheroftheCiscoStackWiseVirtualmemberswitches.
HardwareforwardingisdistributedacrossbothmembersonCiscoStackWiseVirtual.TheCPUontheCisco
StackWiseVirtualactiveswitchsendsForwardingInformationBase(FIB)updatestotheCiscoStackWise
Virtualstandbyswitch,whichinturninstallsalltheroutesandadjacenciesintohardware.
Packetsintendedforalocaladjacency(reachablebylocalports)areforwardedlocallyontheingressswitch.
Packetsintendedforaremoteadjacency(reachablebyremoteports)musttraversetheStackWiseVirtual
link.
TheCPUontheCiscoStackWiseVirtualactiveswitchperformsallsoftwareforwardingandfeatureprocessing
(suchasfragmentationandTimetoLiveexceedfunctions).Ifaswitchoveroccurs,softwareforwardingis
disrupteduntilthenewCiscoStackWiseVirtualactiveswitchobtainsthelatestCiscoExpressForwarding
andotherforwardinginformation.
Invirtualswitchmode,therequirementstosupportnon-stopforwarding(NSF)matchthoseinthestandalone
redundantmodeofoperation.
Fromaroutingpeerperspective,Multi-ChassisEtherChannels(MEC)remainoperationalduringaswitchover,
thatis,onlythelinkstothefailedswitcharedown,buttheroutingadjacenciesremainvalid.
CiscoStackWiseVirtualachievesLayer3loadbalancingoverallthepathsintheForwardingInformation
Baseentries,beitlocalorremote.
IPv6
CiscoStackWiseVirtualsupportsIPv6unicastandmulticastbecauseitispresentinthestandalonesystem.
IPv4Multicast
TheIPv4multicastprotocolsrunontheCiscoStackWiseVirtualactiveswitch.InternetGroupManagement
Protocol(IGMP)andProtocolIndependentMulticast(PIM)protocolpacketsreceivedontheCiscoStackWise
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Layer3Protocols

11. VirtualstandbyswitcharetransmittedacrossaStackWiseVirtuallinktotheStackWiseVirtualactiveswitch.
ThelattergeneratesIGMPandPIMprotocolpacketstobesentoverportsoneitheroftheCiscoStackWise
Virtualmembers.
TheCiscoStackWiseVirtualactiveswitchsynchronizestheMulticastForwardingInformationBase(MFIB)
statetotheCiscoStackWiseVirtualstandbyswitch.Onboththememberswitches,allthemulticastroutes
areloadedinthehardware,withreplicaexpansiontable(RET)entriesprogrammedforonlylocal,outgoing
interfaces.Boththememberswitchesarecapableofperforminghardwareforwarding.
Toavoidmulticastroutechangesasaresultofaswitchover,werecommendthatallthelinkscarryingmulticast
trafficbeconfiguredasMECratherthanEqualCostMultipath(ECMP).
Note
ForpacketstraversingaStackWiseVirtuallink,allLayer3multicastreplicationsoccurontheegressswitch.
Iftherearemultiplereceiversontheegressswitch,onlyonepacketisreplicatedandforwardedoverthe
StackWiseVirtuallink,andthenreplicatedtoallthelocalegressports.
SoftwareFeatures
SoftwarefeaturesrunonlyontheCiscoStackWiseVirtualactiveswitch.IncomingpacketstotheCisco
StackWiseVirtualstandbyswitchthatrequiresoftwareprocessingaresentacrossaStackWiseVirtuallink
totheCiscoStackWiseVirtualactiveswitch.
Dual-ActiveDetection
IfthestandbyswitchdetectsacompletelossoftheStackWiseVirtuallink,itassumestheactiveswitchhas
failedandwilltakeoverastheactiveswitch.However,iftheoriginalCiscoStackWiseVirtualactiveswitch
isstilloperational,boththeswitcheswillnowbeCiscoStackWiseVirtualactiveswitches.Thissituationis
calledadual-activescenario.Thisscenariocanhaveadverseeffectsonnetworkstabilitybecauseboththe
switchesusethesameIPaddresses,SSHkeys,andSTPbridgeIDs.CiscoStackWiseVirtualdetectsa
dual-activescenarioandtakesrecoveryaction.Dual-active-detectionlinkisthededicatedlinkusedtomitigate
this.
IfaStackWiseVirtuallinkfails,theCiscoStackWiseVirtualstandbyswitchcannotdeterminethestateof
theCiscoStackWiseVirtualactiveswitch.Toensurethatswitchoveroccurswithoutdelay,theCiscoStackWise
VirtualstandbyswitchassumesthattheCiscoStackWiseVirtualactiveswitchhasfailedandinitiatesswitchover
totakeovertheCiscoStackWiseVirtualactiverole.TheoriginalCiscoStackWiseVirtualactiveswitch
entersrecoverymodeandbringsdownalltheinterfacesexcepttheStackWiseVirtuallinkandthemanagement
interfaces.
Dual-Active-DetectionLinkwithFastHello
Tousethedual-activefasthellopacketdetectionmethod,youmustprovisionadirectethernetconnection
betweenthetwoCiscoStackWiseVirtualswitches.Youcandedicateuptofourlinksforthispurpose.
Thetwoswitchesperiodicallyexchangespecialdual-activehellomessagescontaininginformationaboutthe
switchstate.IfallSVLsfailandadual-activescenariooccurs,eachswitchrecognizesthatthereisadual-active
scenariofromthepeer'smessages.ThisinitiatesrecoveryactionsasdescribedintheRecoveryActions,on
page12section.Ifaswitchdoesnotreceiveanexpecteddual-activefasthellomessagefromthepeerbefore
thetimerexpires,theswitchassumesthatthelinkisnolongercapableofdual-activedetection.
ConfiguringCiscoStackWiseVirtual
11
ConfiguringCiscoStackWiseVirtual
Dual-ActiveDetection

12. DonotusethesameportforSVLandDADlink.Note
Dual-ActiveDetectionwithenhancedPAgP
Portaggregationprotocol(PAgP)isaCiscoproprietaryprotocolusedformanagingEtherChannels.Ifa
StackWiseVirtualMECterminatesonaCiscoswitch,youcanrunPAgPprotocolontheMEC.IfPAgPis
runningontheMECsbetweentheStackWiseVirtualswitchandanupstreamordownstreamswitch,the
StackWiseVirtualcanusePAgPtodetectadual-activescenario.TheMECmusthaveatleastoneporton
eachswitchoftheStackWiseVirtualsetup.
EnhancedPAgPisanextensionofthePAgPprotocol.Invirtualswitchmode,ePAgPmessagesincludea
newtypelengthvalue(TLV)whichcontainstheIDoftheStackWiseVirtualactiveswitch.Onlyswitchesin
virtualswitchmodesendthenewTLV.
WhentheStackWiseVirtualstandbyswitchdetectsSVLfailure,itinitiatesSSOandbecomesStackWise
Virtualactive.SubsequentePAgPmessagessenttotheconnectedswitchfromthenewlyStackWiseVirtual
activeswitchcontainthenewStackWiseVirtualactiveID.TheconnectedswitchsendsePAgPmessages
withthenewStackWiseVirtualactiveIDtobothStackWiseVirtualswitches.
IftheformerlyStackWiseVirtualactiveswitchisstilloperational,itdetectsthedual-activescenariobecause
theStackWiseVirtualactiveIDintheePAgPmessageschanges.
Figure2:Dual-active-detectionwithePAgP
ToavoidPAgPflapsandtoensurethatdual-activedetectionfunctionsasexpected,thestackMACpersistent
waittimermustbeconfiguredasindefiniteusingthecommandstack-macpersistenttimer0.
Note
RecoveryActions
ACiscoStackWiseVirtualactiveswitchthatdetectsadual-activeconditionshutsdownallofitsnon-SVL
interfacestoremoveitselffromthenetwork.TheswitchthenwaitsinrecoverymodeuntiltheSVLshave
beenrecovered.YoushouldphysicallyrepairtheSVLfailureandtherecoveryswitchshouldbemanually
reloadedforittobethestandbyswitch.
ConfiguringCiscoStackWiseVirtual
12
ConfiguringCiscoStackWiseVirtual
Dual-ActiveDetectionwithenhancedPAgP

13. ImplementingCiscoStackWiseVirtual
Thetwo-nodesolutionofCiscoStackWiseVirtualisnormallydeployedattheaggregationlayer.Twoswitches
areconnectedoveranSVL.
CiscoStackWiseVirtualcombinesthetwoswitchesintoasinglelogicalswitchwithalargenumberofports,
offeringasinglepointofmanagement.Oneofthememberswitchesistheactiveandworksasthecontrol
andmanagementplane,whiletheotheroneisthestandby.Thevirtualizationofmultiplephysicalswitches
intoasinglelogicalswitchisonlyfromacontrolandmanagementperspective.Becauseofthecontrolplane
beingcommon,itmaylooklikeasinglelogicalentitytopeerswitches.Thedataplaneoftheswitchesare
converged,thatis,theforwardingcontextofaswitchmightbepassedtotheothermemberswitchforfurther
processingwhentrafficisforwardedacrosstheswitches.However,thecommoncontrolplaneensuresthat
alltheswitcheshaveequivalentdataplaneentryforeachforwardingentity.
Figure3:Two-NodeSolution
AnelectionmechanismthatdetermineswhichswitchisCiscoStackWiseVirtualactiveandwhichoneisa
controlplanestandby,isavailable.Theactiveswitchisresponsibleformanagement,bridgingandrouting
protocols,andsoftwaredatapath.ThesearecentralizedontheactiveswitchsupervisoroftheCiscoStackWise
Virtualactiveswitch.
HowtoConfigureCiscoStackWiseVirtual
ConfiguringCiscoStackWiseVirtualSettings
ToenableStackWiseVirtual,performthefollowingprocedureonboththeswitches:
Procedure
PurposeCommandorAction
EnablesprivilegedEXECmode.enableStep1
Example: •Enteryourpasswordifprompted.
Device>enable
(Optional)Reassignstheswitchnumber.switchswitch-numberrenumbernewswitch
-number
Step2
ConfiguringCiscoStackWiseVirtual
13
ConfiguringCiscoStackWiseVirtual
ImplementingCiscoStackWiseVirtual

14. PurposeCommandorAction
Thedefaultswitchnumberwillbe1.Thevalid
valuesforthenewswitchnumberare1and2.
Example:
Device#switch1renumber 2
(Optional)Assignstheprioritynumber.switchswitch-numberprioritypriority-numberStep3
Example: Thedefaultprioritynumberis1.Thehighest
prioritynumberis15.
Device#switch1priority5
Entersglobalconfigurationmode.configureterminal
Example:
Step4
Device#configureterminal
EnablesCiscoStackWiseVirtualandenters
stackwise-virtualsubmode.
stackwise-virtual
Example:
Step5
Device(config)#stackwise-virtual
(Optional)SpecifiestheCiscoStackWise
VirtualdomainID.
ThedomainIDrangeisfrom1to255.The
defaultvalueisone.
domainid
Example:
Device(config-stackwise-virtual)# domain
2
Step6
ReturnstoprivilegedEXECmode.end
Example:
Step7
Device(config-stackwise-virtual)# end
showstackwise-virtualStep8
Example:
Device#showstackwise-virtual
Savestherunning-configurationwhichresides
inthesystemRAMandupdatestheROMmon
writememory
Example:
Step9
variables.Ifyoudonotsavethechanges,the
Device#writememory
changeswillnolongerbepartofthestartup
configurationwhentheswitchreloads.Note
thattheconfigurationsforstackwise-virtual
anddomainaresavedtothe
running-configurationandthe
startup-configurationafterthereload.
Restartstheswitchandformsthestack.reload
Example:
Step10
ConfiguringCiscoStackWiseVirtual
14
ConfiguringCiscoStackWiseVirtual
ConfiguringCiscoStackWiseVirtualSettings

15. PurposeCommandorAction
Device#reload
ConfiguringCiscoStackWiseVirtualLink
Dependingontheswitchmodel,SVLissupportedonall10Ginterfacesand40GinterfacesoftheCisco
Catalyst9500Seriesswitchesandonallthe100G,40G,25Gand10GinterfacesoftheCiscoCatalyst9500
SeriesHighPerformanceswitches.However,acombinationofdifferentinterfacespeedsisnotsupported.
Note
ToconfigureaswitchportasanSVLport,performthefollowingprocedureonboththeswitches:
Procedure
PurposeCommandorAction
EnablesprivilegedEXECmode.enableStep1
Example: •Enteryourpasswordifprompted.
Device>enable
Entersglobalconfigurationmode.configureterminal
Example:
Step2
Device#configureterminal
Entersethernetinterfaceconfigurationmode.Performonetheofthefollowingdependingon
theswitchthatyouareconfiguring.
Step3
•IfyouareconfiguringaCiscoCatalyst
9500SeriesSwitch,useinterface
{TenGigabitEthernet|FortyGigabitEthernet}<interface>
•IfyouareconfiguringaCiscoCatalyst
9500SeriesHighPerformanceSwitch,use
interface{HundredGigE
|FortyGigabitEthernet
|TwentyFiveGigE}<interface>
Example:
Device(config)#interface
TenGigabitEthernet1/0/2
AssociatestheinterfacewithconfiguredSVL.stackwise-virtuallinklinkvalue
Example:
Step4
Device(config-if)#stackwise-virtual link
1
ConfiguringCiscoStackWiseVirtual
15
ConfiguringCiscoStackWiseVirtual
ConfiguringCiscoStackWiseVirtualLink

16. PurposeCommandorAction
ReturnstoprivilegedEXECmode.end
Example:
Step5
Device(config-if)#end
Savestherunning-configurationwhichresides
inthesystemRAMandupdatestheROMmon
writememory
Example:
Step6
variables.Ifyoudonotsavethechanges,the
Device#writememory
changeswillnolongerbepartofthestartup
configurationwhentheswitchreloads.Note
thattheconfigurationforstackwise-virtual
linklinkvalueissavedonlyinthe
running-configurationandnotthe
startup-configuration.
Restartstheswitch.reloadStep7
Example: Note
WhenconvertingaCiscoCatalyst9500Series
HighPerformanceswitchfromstandalonemode
Device#reload
toSVLmodeforthefirsttime,oneofthe
switchesbootsuporresets,forresolvingthe
switchnumberconflictandsetsthe
SWITCH_NUMBER environmentvariableto
2.Thefollowingmessageappearsonthe
consolepromptindicatingthis:
Waitingforremotechassistojoin
#######################################################################
Chassisnumberis2
Allchassisinthestackhavebeen
discovered.Acceleratingdiscovery
Chassisisreloading,reason:Configured
Switchnumconflictswithpeer,
Changinglocalswitchnumberto2and
reloadingtotakeeffect
ConfiguringStackWiseVirtualFastHelloDual-Active-DetectionLink
ToconfigureStackWiseVirtualFastHelloDADlink,performthefollowingprocedure.Thisprocedureis
optional.
Procedure
PurposeCommandorAction
EnablesprivilegedEXECmode.enableStep1
Example: •Enteryourpasswordifprompted.
Device>enable
ConfiguringCiscoStackWiseVirtual
16
ConfiguringCiscoStackWiseVirtual
ConfiguringStackWiseVirtualFastHelloDual-Active-DetectionLink

17. PurposeCommandorAction
Entersglobalconfigurationmode.configureterminal
Example:
Step2
Device#configureterminal
Entersethernetinterfaceconfigurationmode.Performonetheofthefollowingdependingon
theswitchthatyouareconfiguring.
Step3
•IfyouareconfiguringaCiscoCatalyst
9500SeriesSwitch,useinterface
{TenGigabitEthernet|FortyGigabitEthernet}<interface>
•IfyouareconfiguringaCiscoCatalyst
9500SeriesHighPerformanceSwitch,use
interface{HundredGigE
|FortyGigabitEthernet
|TwentyFiveGigE}<interface>
Example:
Device(config)#interface
TenGigabitEthernet1/0/40
AssociatestheinterfacewithStackWiseVirtual
dual-active-detection.
stackwise-virtualdual-active-detection
Example:
Step4
Thiscommandwillnotbevisibleon
thedeviceaftertheconfiguration,
butwillcontinuetofunction.
Note
Device(config-if)#stackwise-virtual
dual-active-detection
ReturnstoprivilegedEXECmode.end
Example:
Step5
Device(config-if)#end
Savestherunning-configurationwhichresides
inthesystemRAMandupdatestheROMmon
writememory
Example:
Step6
variables.Ifyoudonotsavethechanges,the
Device#writememory
changeswillnolongerbepartofthestartup
configurationwhentheswitchreloads.Note
thattheconfigurationforstackwise-virtual
dual-active-detectionissavedonlyinthe
running-configurationandnotthe
startup-configuration.
Restartstheswitchandconfigurationtakes
effect.
reload
Example:
Step7
Device#reload
ConfiguringCiscoStackWiseVirtual
17
ConfiguringCiscoStackWiseVirtual
ConfiguringStackWiseVirtualFastHelloDual-Active-DetectionLink

18. EnablingePAgPDual-Active-Detection
ToenableePAgPdual-active-detectiononaswitchport,performthefollowingprocedureon.Thisprocedure
isoptional.
Procedure
PurposeCommandorAction
EnablesprivilegedEXECmode.enableStep1
Example: •Enteryourpasswordifprompted.
Device>enable
Entersglobalconfigurationmode.configureterminal
Example:
Step2
Device#configureterminal
Enterstheinterfaceconfigurationmode.interface{TenGigabitEthernet|
FortyGigabitEthernet|TwentyFiveGigE
}<interface>
Step3
Example:
Device(config)#interface
FortyGigabitEthernet 1/0/5
EnablesPAgPMECwithchannel-groupidin
therangeof1to126for10GigabitEthernet
interfaces.
channel-groupgroup_IDmodedesirable
Example:
Device(config-if)#channel-group1mode
desirable
Step4
Exitsinterfaceconfiguration.exit
Example:
Step5
Device(config-if)#exit
Selectsaportchannelinterfacetoconfigure.interfaceport-channelchannel-group-id
Example:
Step6
Device(config)#interfaceport-channel
1
Shutsdownaninterface.shutdown
Example:
Step7
Device(config-if)#shutdown
Exitsinterfaceconfiguration.exit
Example:
Step8
Device(config-if)#exit
ConfiguringCiscoStackWiseVirtual
18
ConfiguringCiscoStackWiseVirtual
EnablingePAgPDual-Active-Detection

19. PurposeCommandorAction
EnterstheStackWiseVirtualconfiguration
mode.
stackwise-virtual
Example:
Step9
Device(config)#stackwise-virtual
Enablespagpdual-activedetection.Thisis
enabledbydefault.
dual-activedetectionpagp
Example:
Step10
Device(config-stackwise-virtual)#dual-active
detectionpagp
Enablesdual-activedetectiontrustmodeon
channel-groupwiththeconfiguredID.
dual-activedetectionpagptrust
channel-groupchannel-groupid
Example:
Step11
Device(config-stackwise-virtual)#dual-active
detectionpagptrustchannel-group1
ExitstheStackWise-Virtualconfiguration
mode.
exit
Example:
Step12
Device(config-stackwise-virtual)# exit
Configuredport-channelontheswitch.interfaceport-channelportchannel
Example:
Step13
Device(config)#interfaceport-channel
1
Enablestheconfiguredport-channelonthe
switch.
noshutdown
Example:
Step14
Device(config-if)#noshutdown
Exitsinterfaceconfiguration.end
Example:
Step15
Device(config-if)#end
Savestherunning-configurationwhichresides
inthesystemRAMandupdatestheROMmon
writememory
Example:
Step16
variables.Ifyoudonotsavethechanges,the
Device#writememory
changeswillnolongerbepartofthestartup
configurationwhentheswitchreloads.Note
thattheconfigurationfordual-active
detectionpagptrustchannel-group
channel-groupidissavedtothe
running-configurationandthe
startup-configurationafterthereload.
Restartstheswitchandconfigurationtakes
effect.
reload
Example:
Step17
ConfiguringCiscoStackWiseVirtual
19
ConfiguringCiscoStackWiseVirtual
EnablingePAgPDual-Active-Detection

20. PurposeCommandorAction
Device#reload
DisablingCiscoStackWiseVirtual
TodisableCiscoStackWiseVirtualonaswitch,performthefollowingprocedure:
Procedure
PurposeCommandorAction
EnablesprivilegedEXECmode.enableStep1
Example: •Enteryourpasswordifprompted.
Device>enable
Entersglobalconfigurationmode.configureterminal
Example:
Step2
Device#configureterminal
Entersethernetinterfaceconfigurationmode.Performonetheofthefollowingdepending
ontheswitchthatyouareconfiguring.
Step3
•IfyouareconfiguringaCiscoCatalyst
9500SeriesSwitch,useinterface
{TenGigabitEthernet|FortyGigabitEthernet}<interface>
•IfyouareconfiguringaCiscoCatalyst
9500SeriesHighPerformanceSwitch,
useinterface{HundredGigE
|FortyGigabitEthernet
|TwentyFiveGigE}<interface>
Example:
Device(config)#interface
TenGigabitEthernet 1/0/41
DissociatestheinterfacefromStackWise
VirtualDAD.
nostackwise-virtualdual-active-detection
Example:
Step4
Device(config-if)#nostackwise-virtual
dual-active-detection
Enterstheinterfaceconfigurationmode.RepeatstepStep3,onpage20.
Example:
Step5
Device(config)#interface
TenGigabitEthernet 1/0/5
ConfiguringCiscoStackWiseVirtual
20
ConfiguringCiscoStackWiseVirtual
DisablingCiscoStackWiseVirtual

21. PurposeCommandorAction
DissociatestheinterfacefromSVL.nostackwise-virtuallinklink
Example:
Step6
Device(config-if)#nostackwise-virtual
link1
Exitsinterfaceconfiguration.exit
Example:
Step7
Device(config-if)#exit
DisablesStackWiseVirtualconfiguration.nostackwise-virtual
Example:
Step8
Device(config)#nostackwise-virtual
Exitstheglobalconfigurationmode.exit
Example:
Step9
Device(config)#exit
Savestherunningconfiguration.writememory
Example:
Step10
Device#writememory
Restartstheswitchandtheconfigurationtakes
effect.
reload
Example:
Step11
Device#reload
VerifyingCiscoStackWiseVirtualConfiguration
ToverifyyourStackWiseVirtualconfiguration,usethefollowingshowcommands:
Displaysinformationofaparticularswitchinthestack.showstackwise-virtualswitchnumber<1-2>
DisplaysStackWiseVirtuallinkinformation.showstackwise-virtuallink
DisplaysthebandwidthavailablefortheCiscoStackWise
Virtual.
showstackwise-virtualbandwidth
DisplaystheCiscoStackWiseVirtualneighbors.showstackwise-virtualneighbors
DisplaysStackWiseVirtualdual-active-detection
information.
showstackwise-virtualdual-active-detection
DisplaysePAgPdual-active-detectioninformation.showstackwise-virtualdual-active-detection
pagp
ConfiguringCiscoStackWiseVirtual
21
ConfiguringCiscoStackWiseVirtual
VerifyingCiscoStackWiseVirtualConfiguration

22. AdditionalReferencesforStackWiseVirtual
RelatedDocuments
DocumentTitleRelatedTopic
HighAvailabilityCommandReferenceforCatalyst9500
Switches
Forcompletesyntaxandusageinformationfor
thecommandsusedinthischapter.
MIBs
MIBsLinkMIB
TolocateanddownloadMIBsforselectedplatforms,CiscoIOSreleases,
andfeaturesets,useCiscoMIBLocatorfoundatthefollowingURL:
http://www.cisco.com/go/mibs
AllthesupportedMIBsforthis
release.
TechnicalAssistance
LinkDescription
http://www.cisco.com/supportTheCiscoSupportwebsiteprovidesextensiveonlineresources,including
documentationandtoolsfortroubleshootingandresolvingtechnicalissues
withCiscoproductsandtechnologies.
Toreceivesecurityandtechnicalinformationaboutyourproducts,youcan
subscribetovariousservices,suchastheProductAlertTool(accessedfrom
FieldNotices),theCiscoTechnicalServicesNewsletter,andReallySimple
Syndication(RSS)Feeds.
AccesstomosttoolsontheCiscoSupportwebsiterequiresaCisco.comuser
IDandpassword.
FeatureHistoryforCiscoStackWiseVirtual
Thistableprovidesreleaseandrelatedinformationforfeaturesexplainedinthismodule.
Thesefeaturesareavailableonallreleasessubsequenttotheonetheywereintroducedin,unlessnoted
otherwise.
ConfiguringCiscoStackWiseVirtual
22
ConfiguringCiscoStackWiseVirtual
AdditionalReferencesforStackWiseVirtual

23. FeatureInformationFeatureRelease
CiscoStackWiseVirtualisanetworksystem
virtualizationtechnologythatpairstwoswitches
intoonevirtualswitchtosimplifyoperational
efficiencywithasinglecontrolandmanagement
plane.
Supportforthisfeaturewasintroducedonthe
C9500-12Q,C9500-16X,C9500-24Q,C9500-40X
modelsoftheCiscoCatalyst9500SeriesSwitches
CiscoStackWiseVirtualCiscoIOSXEEverest16.6.1
CiscoStackWiseVirtualisanetworksystem
virtualizationtechnologythatpairstwoswitches
intoonevirtualswitchtosimplifyoperational
efficiencywithasinglecontrolandmanagement
plane.
Supportforthisfeaturewasintroducedonthe
C9500-32C,C9500-32QC,C9500-48Y4C,and
C9500-24Y4CmodelsoftheCiscoCatalyst9500
SeriesSwitches.
CiscoStackWiseVirtualCiscoIOSXEGibraltar
16.10.1
UseCiscoFeatureNavigatortofindinformationaboutplatformandsoftwareimagesupport.ToaccessCisco
FeatureNavigator,gotohttp://www.cisco.com/go/cfn.
ConfiguringCiscoStackWiseVirtual
23
ConfiguringCiscoStackWiseVirtual
FeatureHistoryforCiscoStackWiseVirtual

24. ConfiguringCiscoStackWiseVirtual
24
ConfiguringCiscoStackWiseVirtual
FeatureHistoryforCiscoStackWiseVirtual