PPTAPICMod03 - Packet Forwarding

Nexus9000StandaloneModePacketForwarding,Thenextgenerationofdatacenterswitching,ForwardingBehaviorOverview,Thismodulewillexplore:UnicastForwardingMulticastForwardingAccessControlListsQualityofServiceBufferManagement,ForwardingBehaviorUnicastForwarding,ForwardingBehaviorUnicastPipelineNexus9500Overview,UnicastVoQ,NXOSModeOnly,ForwardingBehaviorUnicastPacketProcessorPipelineIntelligentParser,ExaminesingresspacketsfromallphysicalportsEthernetPortsHiGigportsCMICportParsethefirst128bytesofpackettoextractinformationincluding:Layer2headerEtherTypeL3headerTCP/IPprotocolsTheextractedinformationissavedfordifferentsearchenginestouse.,NXOSModeOnly,ForwardingBehaviorUnicastPacketProcessorPipelineTunnelTermination,TunnelTerminationdetermineswhetherthedeviceisthetunnelendpointfortheincomingtunnelpackets(IP,VxLAN,etc).IfthetunnelheaderlookupresolvesamatchinMY_STATIONtable,thenthedeviceisbethetunnelendpoint,willproceedforthefurtherprocessofinnerpacket.,NXOSModeOnly,ForwardingBehaviorUnicastPacketProcessorPipelineLayer2/Layer3Lookup,L2Switchinglogicperforms:VLANlookupL2unicastlookupL2multicastlookupMACsourceaddresslookupsforhardware-basedlearning,L3Routinglogicperforms:L3unicastlookupL3multicastlookupLPMlookupLineCardonlyinstalls0.0.0.0/0inLPMtableuRPFchecks,NXOSModeOnly,ForwardingBehaviorUnicastPacketProcessorPipelineForwardingTableScaling,ThepacketProcessorusesUnifiedForwardingTable(UFT)toflexiblyaccommodatethreeforwardingtablesbasedondifferentdeploymentscenarios:Layer2TableLayer3HostRoutesTableLPM(LongestPrefixMatch)Table,NXOSModeOnly,DedicatedL2MACEntries:32kx105bits,SharedEntries:256kx105bits,DedicatedL3HostEntries:16kx105bits,SUPPORTEDCOMBINATIONS,ThePacketProcessorhasa16KtraditionalLPMTCAM.Inadditiontoit,thePacketProcessorhasthefollowingUnifiedForwardingTable:,FabricmodulePacketprocessorisprogrammedinMode4togetthemaxLPMtable.,LinecardPacketProcessorisprogrammedinMode2togetlargeandbalancedLayer-2MACtableandLayer-3Hosttable.,ForwardingBehaviorUnicastPacketProcessorPipelineUnifiedForwardingTable,NXOSModeOnly,ForwardingBehaviorUnicastUnicastScaleonNexus9500withMerchant+,LeveragePacketProcessorUFT(UnifiedForwardingTable)todistributeforwardinginformationacrossLineCardandFabricModuleTables.Layer-2MACTableandLayer-3HostRoutesTableareonLineCardsLPMRouteTableisonFabricModulesInstalladefaultroute0.0.0.0/0onLineCardsusingthevirtualMODIDofFabricModuleastheDMODtoforceLineCardstoforwardLPMpacketstoFabricModules;FabricModulesperformLPMlookupandforwardpacketstotheresolvedDMOD/DPORT,PP,FabricCard,PP,PP,EPP,LineCard,*Sharedwithmulticast,NXOSModeOnly,ForwardingBehaviorUnicastUnicastScaleonNexus9500withMerchant+,OnlyLayer-2MACandLayer-3hostroutesarelookedupontheingressLineCard.AdefaultrouteisprogrammedontheLineCardtopointtoFabricModulesforLongestPrefixMatch(LPM)lookup.AlltheLineCardPacketProcessorASICshavethesameentries.ThisallowsscaletothecapacityofasinglechipofaLCforLayer-2MACaddressesandLayer-3hostroutes.AllPacketProcessorASICsontheFabricModuleshavethesameentriesscalingthecapacityofachipforLayer-3LPMlookups.Eachlookupprovidesaresultintermsofa(destination-module,destination-port)tuplethatallowsforpacketstobesenttotheappropriatelinecardandport.,NXOSModeOnly,ForwardingBehaviorNexus9500UnicastPacketWalk,ForwardingBehaviorUnicastPacketWalkLayer-2,Parser,NetworkInterfaces,L2/L3LookupSendsonecopytoeachegr.module;,L2/L3mcastlkup;Replicatepcktstolocalreceivingports;Send1copytofabricmodule;,Examinesingresspacket.Getpacketheadersforprocessing.,NorthStarforwardpcktstoFabricModule,NorthStarforwardpcktstolocalT2,Lookupforlocalreceivingports;replicatepktsontothoseports.,NXOSModeOnly,ForwardingBehaviorMulticastStandaloneIGMPSnooping,SourceIPandgroupaddressbasedforwardingforIGMPv3snoopingevenwhenN9000isL2switchCanfiltertrafficbasedonsourceIPforIGMPv3NoconcernofoverlappingmulticastMACaddresses,H1,1.1.1.10,Group:224.1.1.1Include:10.0.0.1,v3Report(224.0.0.22),MulticastMACbasedforwarding,IPbasedforwarding,VLAN100100.5E01.0101eth1/1,VLAN1010.0.0.1224.1.1.1eth1/1,NXOSModeOnly,ForwardingBehaviorACLSupport,ForwardingBehaviorAccessControlListsPacketProcessorPipelineForwardingTableScaling,TheACLModule(AC)performsthefollowingfunctionsSecurityACLs:IFACL,VACL,RBACLQoSACLs:ClassificationSupervisorRedirect:TrafficbasedSPAN:Ingress/EgressSPANsessionclassification,packetsamplingNetworkAddressTranslation(NAT)PolicyBasedRouting(PBR)COPPtrafficclassification,NXOSModeOnly,ForwardingBehaviorAccessControlListsNexus9500ACLSupports,Nexus9500supportsawiderangeofACLtypes:(AllACLtypessupportIPv4,IPv6andMACwhenapplicable.),Ingress,Egress,IngressACL:4Kentriesoneachlinecard(4x512banks+8x256banks)EgressACL:1Kentriesoneachlinecard(4x256banks),NXOSModeOnly,ForwardingBehaviorAccessControlListsNexus9500DefaultACLTCAMAllocation,TheallocationofbothingressandegressACLTCAMtodifferentACLtypesisuserconfigurable.Thedefaultsettingisshownbelow:,9508-1#showhardwareaccess-listtcamregion|ex=0TCAMRegionSizes:IPV4PACLsize=512IPV4PortQoSsize=512IPV4VACLsize=256IPV4VLANQoSsize=256IPV4RACLsize=256EgressIPV4VACLsize=256EgressIPV4RACLsize=256IPV4L3QoSsize=256IngressSystemsize=256EgressSystemsize=256SPANsize=256IngressCOPPsize=2569508-1#,NoteACLtypesthatarenotinthelisthavedefaultsizeof0Thissettingisuserconfigurable.Changestakeeffectonapermodulebasis.NeedtoreloadthemodulesorthesystemTheCLIcommandtoshowtheACLTCAMcarvingisshowhardwareaccess-listtcamregionTheCLIcommandtochangeACLTCAMcarvingishardwareaccess-listtcamregionACLtypetcamsize,EachACLtypeneedsitsowndedicatedbank/banks;IPv4,IPv6orMACeachneedsdedicatedbank/banks;IPv6andMACACLsneedsdouble-widthentries,whichmeansIPv6orMACACLsneedatleast2banks;VACLisprogrammedsymmetricallyinbothegressACLandingressACL;,NXOSModeOnly,ForwardingBehaviorAccessControlListsNexus9500ACLEntriesSharing,WhensameACLpolicy(securityACLsuchasPACL,VACL,RACLorQoSACL)isappliedtomultipleinterfacesorVLANs,onlyonecopyisprogrammedinTCAMwhichissharedbythoseinterfacesandVLANs.EachACLpolicyhaslabel.ByassignsamelabeltomultipleinterfacesandVLANssameTCAMrulecanbeappliestomultipleinterfacesorVLANs.,interfaceEthernet1/10ipportaccess-groupip-list-1ininterfaceEthernet1/11ipportaccess-groupip-list-1ininterfaceEthernet1/12ipportaccess-groupip-list-1in,ipaccess-listip-list-110permitip100.1.1.0/24200.1.1.0/2420permitip100.1.2.0/24200.1.2.0/24,NXOSModeOnly,ForwardingBehaviorQoSandBufferManagement,ForwardingBehaviorQoS/BufferManagement,IngressQoSClassificationPolicy-maptypeqos)MatchonCoS/IPPrecedence/DSCP/ACLSetqos-groupRemarkCoS/IPPrecedence/DSCPIngresspolicingNetwork-QoSPolicy-maptypenetwork-qosMatchonqos-groupEnablePFCEgressQueuingandShapingPolicy-maptypequeueingEnableWREDorECN(defaultistaildrop)4user-definedclassesbasedonqos-group1controlclassforCPUand1classforSPANtraffic3PFCnon-dropqueues3Priorityqueues,NXOSModeOnly,Shared12MBbuffer,Shared10MBbufferforfabricboundtraffic;Shared30MBbufferforfrontpanelboundtraffic.UnicastVoQisusingthisbuffer.,EPP,ToLocalPacketProcessor,ToFabricModules,PacketProcessor,ForwardingBehaviorQoS/BufferManagement-BufferAllocation,NXOSModeOnly,ForwardingBehaviorQoS/BufferManagement-EPPBufferAllocation,NXOSModeOnly,12MB,PP,FabricModule,Port1-48(10GE),Port49-52(40GE),Port1-12(40GE),Port13-24(40GE),Port2536(40GE),EPP,EPP,48-Port1/10GT+4-Port40GI/OModule48-Port1/10GT+4-Port40GI/OModule,36-Port40GI/OModule,ForwardingBehaviorQoS/BufferManagement-BufferStructure,NXOSModeOnly,FabricModule,FabricModule,FabricModule,TridentII,TridentII,TridentII,1GE,10GE,ForwardingBehaviorQoS/BufferManagement-LocalSwitching,TrafficbetweenportsofthesamespeedislocallyswitchedonTridentII.,TrafficfromfastporttoslowportisforwardedtoNorthStarforadditionalbuffers.,TrafficfromslowporttofastportislocallyswitchedonTridentII.,48/4AccessLineCards,NXOSModeOnly,ForwardingBehaviorQoS/BufferManagement-EgressQueuing,Nexus9500switchesaredesignedwithegressqueuingarchitectureforsimpleandefficientbufferutilizationEPPASIConACIreadylinecardsprovidesadditionalbufferstosupportextendedegressqueuingforunicasttrafficEPPASIChasa30MBbufferfortrafficgoingtolinecardPPthatsupportsupto96x4extendedegressqueuesOOBFC(Out-of-BandFlowControl)SignalingbetweenlinecardPPandEPPcontrolsextendedegressqueuesonEPP.UnicasttrafficfromFabricmoduleandhair-pinnedlocalunicasttrafficfromlinecardPPgoesintotheextendedegressqueuesThePPhasadedicatedbufferpoolfortheextendedegressqueues.Othertraffic,includingPPlocallyswitchedUnicast,Multicast,andSPANtrafficshareanotherbufferpoolForeachUnicasttrafficclass,therearetwoqueuesontheegressTridentII,oneisfortrafficfromEPPextendedegressqueues,theotherisPPlocallyswitchedunicasttraffic,NXOSModeOnly,Allusertraffic(unicast+multicast)andspantraffic,ControlTraffic,Default,SharedBuffer(12MB),Control,ForwardingBehaviorQoS/BufferManagementonPP,The12MBbufferonPPissharedforbothingressandegressandbyallTridentIIports.Thebufferiscarvedintotwoservicepools,includingcontrolanddefaultpools.Controlservicepoolisforcontroltrafficandisassigned450cells(93KB)bydefault.Itsupports4user-defaultclassesinthedefaultservicepool,providing4uncastand4multicastuserdefinedqueuesandthespantrafficqueue.,NXOSModeOnly,Non-OOBFCtraffic(locallyswitchedUnicast;Multicast;SPAN),ControlTraffic,Non-OOBFCTraffic,SharedBuffer(12MB),OOBFCUnicast,Control,OOBFCUnicastFraffic,ForwardingBehaviorQoS/BufferManagementonLine-CardPP,The12MBbufferonPPissharedforbothingressandegressandbyallPPports.Thebufferiscarvedintothreeservicepools,includingOut-of-bandFlowControl(OOBFC)traffic,Non-OOBFCtrafficandcontroltraffic.OOBFCclasstrafficisflow-controlledVoQunicasttraffic.Thereareupto96x4queues.Non-OOBFCclasstrafficincludesPPlocallyswitchedunicast,multicastandSPANtraffic.Therereupto96x4multicastand96x4unicastuserdefinedqueuesinadditiontothecontroltrafficqueueandthespantrafficqueue.OOBFCUnicastservicepoolisonlyprovisionedonLineCardsthathaveEPPASIC.,NXOSModeOnly,ForwardingBehaviorQoS/BufferManagementQueuingandSchedulingon36PortSpineLineCard,TrafficClassification,IngressCos/DSCPMarking,IngressPolicing,FabricModule,EgressPortQueues,multicast,span,MTUchecking,PP,IngressLineCard,EgressLineCard,control,NXOSModeOnly,EgressPortQueues,Multicast,Span,LocalUnicast,PP,EgressLineCard,Queue,Control,0,1,2,3,4,5,6,7,ClassofService,0,1,2,3,Control,SPAN,PortN,ForwardingBehaviorQoS/BufferManagementQueuingandSchedulingon36PortSpineLineCard,NXOSModeOnly,The10MBbufferontheEPPisdedicatedforfabric-boundtraffic.ThisBufferiscarvedinto2servicepools,includingcontrolanddefaultpoolsControlservicepoolisforcontroltrafficandisassigned450cells(93KB)bydefault.Itsupportsfouruser-defaultclassesinthedefaultservicepool,providingfourunicastandfourmulticastuserdefinedqueuesaswellasthespantrafficqueue.,Allusertraffic(unicast+multicast)andspantraffic,ControlTraffic,Default,SharedBuffer(12MB),Control,ForwardingBehaviorQoS/BufferManagementFabric-BoundBufferManagementonEPP,NXOSModeOnly,EPPhas30MBbufferforegresstraffictoLine-cardPP.Itprovides4Unicastextendedegressqueuesperegressport;TheextendedegressqueuesarecontrolledbyLCTridentIIthroughOOBFC(Out-of-BandFlowControl);Multicasttrafficandtransitunicasttraffic(unicastt