IEEE8021Q

IETF86–TutorialIEEE802.1QMediaAccessControlBridgesandVirtualBridgedLocalAreaNetworksPatriciaThaler,NormanFinn,DonFedyk,GlennParsons,EricGrayIEEE802.org/1March10,2013Contents•IEEE802.1Overview•Bridgearchitecture•Dataplane•ProviderBridges(PB)/Q-in-Q/•ProviderBackboneBridges(PBB)/MAC-in-MAC/•EdgeVirtualBridging(EVB)•Controlplane•RapidSpanningTreeProtocol(RSTP),MultipleSpanningTreeProtocol(MSTP)•MultipleRegistrationProtocol(MRP)•ShortestPathBridging(SPB)•SoftwareDefinedNetworking(SDN)aspects•Enhancementstobridgingof802.11•Operation,Administration,andMaintenance(OAM):ConnectivityFaultManagement(CFM)•Protectionswitching•Management•QualityofService(QoS)•Enhancedtransmissionselection(ETS)•Priority-basedflowcontrol(PFC)•CongestionNotification(CN)•StreamReservationProtocol(SRP)•Creditbasedshaper•Preemptionandtimescheduledqueuing•Policing•Other802.1standardsnotcoveredbythistutorial•LinkAggregation•LinkLayerDiscoveryProtocol(LLDP)•Timesynchronization•Audiovideobridgingsystems•Bridgeportextension•Security•Summary•References•AbbreviationsIEEE802.1Q4IETF86–TutorialBRIDGEARCHITECTUREMarch10,2013IEEE802.1Q11BasicPrinciples•MACaddressesare“identifier”addresses,not“location”addresses•ThisisamajorLayer2value,notadefect!•Bridgeforwardingisbasedon•DestinationMAC•VLANID(VID)•Framefilteringforonlyforwardingtoproperoutboundports(s)•Frameisforwardedtoeveryport(exceptforreceptionport)withintheframe'sVLANifitisnotknownwheretosendit•Filter(unnecessary)portsifitisknownwheretosendtheframe(e.g.frameisonlyforwardedtowardsthedestination)•QualityofService(QoS)isimplementedaftertheforwardingdecisionbasedon•Priority•DropEligibility•TimeIEEE802.1Q12ControlPlaneSeparatedfromDataPlane•ControlprotocolsareimplementedasHigherLayerEntities•ExternalAgentmayprovidecontrolinsteadofthedistributedprotocols•Thedataplaneiscomprisedof•AMACRelayand•AtleasttwoportsIEEE802.1Q13DataPlaneControlPlaneRelayPortPortExternalAgentMACBridgeHigherLayerEntitiesSimplified“baggypants”modelLANMediaAccessMethodSpecificFunctionsIEEE802.ne.g.802.3Ethernet802.1BridgingLANseeFigure8-2–“VLAN-awareBridgearchitecture”of802.1QformoredetailsIETF86–TutorialDATAPLANEMarch10,2013IEEE802.1Q15DataPlaneToday•802.1Qtodayis802.Q-2011(Revision2013isongoing)•Notethatiftheyearisnotgiveninthenameofthestandard,thenitreferstothelatestrevision,e.g.today802.1Q=802.1Q-2011and802.1D=802.1D-2004•802.1Qalreadyinvolves•Q-in-Q=ProviderBridges(PB)[IEEE802.1ad-2005]•MAC-in-MAC=ProviderBackboneBridges(PBB)[IEEE802.1ah-2008]•802.1Qbg-2012EdgeVirtualBridging(EVB)isalsopartoftoday’s802.1Qdataplane(802.1Qbgnotyetamendedto802.1Q)•802.1Qisnotonlyabout12-bitC-VLANsanymoreIEEE802.1Q16DataPlaneActions•IngressPort(ActionSet1)•Filtering(drop),(un)tagging,VIDtranslation,de/en-capsulation•Relay(ActionSet2)•Forwarding,filtering•EgressPort(ActionSet3)•Filtering,(un)tagging,VIDtranslation,de/en-capsulation,metering,queuing,transmissionselectionIEEE802.1Q17DataPlaneFrameoutFrameinRelayIngressPort(ActionSet1)EgressPort(ActionSet3)MACBridgeIngressPort(ActionSet1)(Table1)Relay(ActionSet2)(Table2)FrameinFrameoutMACBridgeEgressPort(ActionSet3)(Table3)redrawn(“baggypants”issimple)NetworkOverlaysExampleIEEE802.1Q18BackboneProviderNetworkCustomerNetworkProviderEdgeBridgeProviderEdgeBridgeProviderBridgeNetwork(PBN)CoreBridgeProviderEdgeBridgeProviderEdgeBridgeCoreBridgeProviderBridgeNetwork(PBN)CustomerNetworkCustomerNetworkCustomerMACCustomerMACBackboneMACBackboneEdgeBridgeBackboneEdgeBridgeProviderBackboneBridgeNetwork(PBBN)BackboneCoreBridgeVeryroughanalogyofIETFconceptto802.1concept:Pdevice~BCB;PEdevice~BEB;CEdevice~C-MACbridgeBEBBEBBCBNetworkVirtualizationIsBasedontheDataPlane•Dataplaneevolution[upto802.1Q-2011]•itisnotcomplicated•~maythinkoftagstacking•ProviderBridges(PB,Q-in-Q)•Scalability•Overlayingvirtualnetworks•4KVLANproblemsolved•ProviderBackboneBridges(PBB,MAC-in-MAC)•Scalability•24-bitI-SIDasasinglevirtualnetworkID•Forgetaboutthe4KVLANproblem•Separation•MACaddressspaceseparation(C-MACvs.B-MAC)•Servicelayerisseparatedfromtransportlayer(I-SIDvs.B-VID)•Overall•Uniformforwardingkept:basedonDestinationMAC(DA)andVID•L2dataplaneprovidespowerfulvirtualization•TheremaybeseverallevelsoftaggingorencapsulationIEEE802.1Q19802.1DPayloadEthertypeSrcAddrDstAddrPB802.1ad-2005PayloadEthertypeC-VIDEthertypeS-VIDEthertypeC-SAC-DA802.1Q-1998PayloadEthertypeVIDEthertypeSADAPBB802.1ah-2008PayloadI-tagB-tagB-MACS-tagC-tagEthertypeC-VIDEthertypeS-VIDEthertypeC-SAC-DAI-SIDEthertypeB-VIDEthertypeB-SAB-DAVirtualNetworksandOverlays•Virtualnetworknamesdonotboundtheirapplication!•Alotofflexibilityisprovided,twoexamplesshownhere•UsingallL2virtualnetworkoverlays•Canbeusedindatacenterandcampusnetworkstoo,notonlyinproviderenvironment•IPisanativeoverlayonEthernet•IPpayloadcanbee.g.rightafterI-tag•HostcanbeaVirtualMachine•PBBcanbethecoreofadatacenterIEEE802.1Q2020B-VLANI-SIDS-VLANC-VLANI-SIDB-DAB-SAB-VIDEthertypePayloadC-VIDEthertypeC-DAC-SAS-VIDEthertypeEthertypeEthertypeIPSubnetB-VLANI-SIDI-SIDB-DAB-SAB-VIDEthertypePayloadEthertypeC-DAC-SAEthertypePBBCus