CCNA思科网络技术学院教程-第15章_路由选择和路由选择协议

第15章路由选择和路由选择协议,主要内容,介绍路由选择和路由选择协议及区别，介绍距离矢量、链路状态和混合型三种路由选择方式，及如何解决路由选择问题。,15.1路由选择基础,,,15.1路由选择基础,NetworkProtocol,DestinationNetwork,ConnectedLearned,,ExitInterface,E0S0,RoutedProtocol:IP,Routersmustlearndestinationsthatarenotdirectlyconnected,,,E0,S0,WhatisaRoutingProtocol?,Routingprotocolsareusedbetweenrouterstodeterminepathsandmaintainroutingtables.Oncethepathisdeterminedaroutercanroutearoutedprotocol.,NetworkProtocol,DestinationNetwork,ConnectedRIPIGRP,,ExitInterface,E0S0S1,RoutedProtocol:IPRoutingprotocol:RIP,IGRP,,,,E0,S0,StaticRouteUsesaroutethatanetworkadministratorentersintotheroutermanually,15.2StaticRoutes,,SO,1、StaticRoutes,,B,,Network,A,Configureunidirectionalstaticroutestoandfromastubnetworktoallowcommunicationstooccur.,B,StubNetwork,DefinesapathtoanIPdestinationnetworkorsubnet,Router(config)#iproutenetworkmaskaddress|interfacedistancepermanent,StaticRouteConfiguration,StubNetwork,iproute,,SO,StaticRouteExample,,B,,Network,A,B,Thisisaunidirectionalroute.Youmusthavearouteconfiguredintheoppositedirection.,StubNetwork,iproute,2、DefaultRoutes,,SO,,B,,Network,A,B,ThisrouteallowsthestubnetworktoreachallknownnetworksbeyondrouterA.,3、路由的验证及故障排除,1）是否正确配置showrunning-config2）查看路由表showiproute3）检查端口状态showinterface4）检验IP配置，并使用ping测试连通。,DynamicRouteUsesaroutethatanetworkroutingprotocoladjustsautomaticallyfortopologyortrafficchanges,15.3DynamicRoutesOverview,15.4ClassesofRoutingProtocols,DistanceVector,HybridRouting,LinkState,C,B,A,D,C,D,B,A,例：RIP、IGRP,例：EIGRP,例：OSPF,AutonomousSystem100,AutonomousSystem200,IGPs:RIP,IGRP,EGPs:BGP,15.5AutonomousSystems:InteriororExteriorRoutingProtocols,AnautonomoussystemisacollectionofnetworksunderacommonadministrativedomainIGPsoperatewithinanautonomoussystemEGPsconnectdifferentautonomoussystems,RouterconfigurationSelectroutingprotocolsSpecifynetworksorinterfaces,Network,Network,IGRP,RIP,Network,RIP,RIP,IGRP,IPRoutingConfigurationTasks,Blankforpagination,DefinesanIProutingprotocol,Router(config)#routerprotocolkeyword,MandatoryconfigurationcommandforeachIProutingprocessIdentifiesthephysicallyconnectednetworkthatroutingupdatesareforwardedto,Router(config-router)#networknetwork-number,DynamicRoutingConfiguration,19.2kbps,T1,T1,T1,HopcountmetricselectsthepathRoutesupdateevery30seconds,4、RIPOverview,StartstheRIProutingprocess,Router(config)#routerrip,Router(config-router)#networknetwork-number,SelectsparticipatingattachednetworksThenetworknumbermustbeamajorclassfulnetworknumber,RIPConfiguration,,RIPConfigurationExample,,,S2,E0,S3,,,,,S2,S3,,,A,B,C,,E0,VerifyingtheRoutingProtocolRIP,RouterA#shipprotocolsRoutingProtocolisripSendingupdatesevery30seconds,nextduein0secondsInvalidafter180seconds,holddown180,flushedafter240OutgoingupdatefilterlistforallinterfacesisIncomingupdatefilterlistforallinterfacesisRedistributing:ripDefaultversioncontrol:sendversion1,receiveanyversionInterfaceSendRecvKey-chainEthernet0112Serial2112RoutingforNetworks:RoutingInformationSources:GatewayDistanceLastUpdate12000:00:10Distance:(defaultis120),,S2,E0,S3,,,,,S2,S3,,,A,B,C,,E0,DisplayingtheIPRoutingTable,RouterA#shiprouteCodes:C-connected,S-static,I-IGRP,R-RIP,M-mobile,B-BGPD-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinterareaN1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternaltype2E1-OSPFexternaltype1,E2-OSPFexternaltype2,E-EGPi-IS-IS,L1-IS-ISlevel-1,L2-IS-ISlevel-2,*-candidatedefaultU-per-userstaticroute,o-ODRT-trafficengineeredrouteGatewayoflastresortisnotset/24issubnetted,1subnetsCisdirectlyconnected,Ethernet0/24issubnetted,2subnetsR120/1via,00:00:07,Serial2Cisdirectlyconnected,Serial2R/24120/2via,00:00:07,Serial2,,S2,E0,S3,,,,,S2,S3,,,A,B,C,,E0,ReviewQuestions,1.Whatisanadvantageofusingastaticrouteratherthanadynamicroute?Whatisadisadvantage?2.WhatistheadvantageofusingIGRPratherthenRIP?Whatisapossibledisadvantage?3.ToscaleuptoverylargeIPnetworks,whatroutingprotocolsarerecommended?,Uponcompletionofthischapter,youwillbeabletoperformthefollowingtasks:ConfigureHDLCandPPPprotocolsonaserialWANconnectionConfigurePAPandCHAPauthenticationonaPPPconnectionVerifyproperpoint-to-pointHDLCandPPPconfiguration,Objectives,6.3WAN广域网概述,服务提供商,广域网互联各站点根据用户的需求和花费选择不同的连接,租用专线,串行通信,电话公司,电路交换,异步串行,服务提供商,包交换,同步串行,1、WAN连接类型:第一层,LeasedLine,Circuit-switched,PPP,HDLC,PPP,HDLC,Packet-switched,FrameRelay,X.25,ATM,2、典型WAN封装协议:第二层,TelephoneCompany,ServiceProvider,租用专线,电路交换,包交换,Point-to-pointorcircuit-switchedconnection,COSwitch,CustomerPremisesEquipment,Demarcation,LocalLoop,WANserviceprovidertollnetwork,Trunksandswitches,InterfacingWANServiceProviders,Providerassignsconnectionparameterstosubscriber,3、串行点对点连接,路由器端连接,在CSU/DSU端的网络连接,EIA/TIA-232,EIA/TIA-449,EIA-530,V.35,X.21,CSU/DSU,终端用户设备,服务提供商,DTE,DCE,PPPEncapsulation,TCP/IPNovellIPXAppleTalk,MultipleprotocolencapsulationsusingNCPsinPPP,PPPcancarrypacketsfromseveralprotocolsuitesusingNetworkControlProgramsPPPcontrolsthesetupofseverallinkoptionsusingLCP,LinksetupandcontrolusingLCPinPPP,AnOverviewofPPP,Feature,HowItOperates,Protocol,Authentication,PAP,CHAP,PerformChallengeHandshake,Requireapassword,Compression,Compressdataatsource;reproducedataatdestination,StackerorPredictor,ErrorDetection,Avoidframelooping,Monitordatadroppedonlink,MagicNumber,Multilink,Loadbalancingacrossmultiplelinks,MultilinkProtocol(MP),PPPLCPConfigurationOptions,PPPAuthenticationOverview,TwoPPPauthenticationprotocols:PAPandCHAP,PPPSessionEstablishment1LinkEstablishmentPhase2OptionalAuthenticationPhase3Network-LayerProtocolPhase,DialuporCircuit-SwitchedNetwork,4、配置PPP,Router(config-if)#encapsulationppp,EnablePPPencapsulation,ConfiguringCHAPExample,hostnameleftusernamerightpasswordsameone!intserial0ipaddressencapsulationppppppauthenticationCHAP,hostnamerightusernameleftpasswordsameone!intserial0ipaddressencapsulationppppppauthenticationCHAP,Leftrouter,Rightrouter,PSTN/ISDN,5、什么是ISDN?,Providernetwork,DigitalPBX,Smalloffice,Homeoffice,提供语音、数据、视频和专用服务,Telecommuter,Centralsite,6、FrameRelayOverview,VirtualcircuitsmakeconnectionsConnection-orientedservice,FrameRelayworkshere.,DCEorFrameRelaySwitch,CSU/DSU,FrameRelayStack,OSIReferenceModel,FrameRelay,Physical,Presentation,Session,Transport,Network,DataLink,Application,EIA/TIA-232,EIA/TIA-449,V.35,X.21,EIA/TIA-530,FrameRelay,IP/IPX/AppleTalk,etc.,FrameRelayTerminology,LocalAccessLoop=T1,LocalAccessLoop=64kbps,LocalAccessLoop=64kbps,DLCI:400,PVC,DLCI:500,LMI100=Active400=Active,DLCI:200,DLCI:100,PVC,CSU/DSU,FrameRelayAddressMapping,GetlocallysignificantDLCIsfromproviderMapyournetworkaddressestoDLCIs,DLCI:500,PVC,,InverseARPorFrameRelaymap,IP(),FrameRelay,DLCI(500),FrameRelaySignaling,CiscosupportsthreeLMIstandards:CiscoANSIT1.617AnnexDITU-TQ.933AnnexA,DLCI:400,PVC,Keepalive,CSU/DSU,DLCI:500,PVC,,x,LMI500=Active400=Inactive,FrameRelayInverseARPandLMIOperation,FrameRelayCloud,1,DLCI=100,DLCI=400,,,FrameRelayInverseARPandLMIOperation,2,StatusInquiry,2,StatusInquiry,FrameRelayCloud,1,DLCI=100,DLCI=400,,,FrameRelayInverseARPandLMIOperation,3,LocalDLCI100=Active,4,LocalDLCI400=Active,2,StatusInquiry,2,StatusInquiry,FrameRelayCloud,1,DLCI=100,DLCI=400,3,,,FrameRelayInverseARPandLMIOperation,4,Hello,Iam.,3,LocalDLCI100=Active,4,LocalDLCI400=Active,2,StatusInquiry,2,StatusInquiry,FrameRelayCloud,1,DLCI=100,DLCI=400,3,,,FrameRelayInverseARPandLMIOperation(cont.),Hello,Iam.,4,5,FrameRelayMapDLCI400Active,FrameRelayCloud,DLCI=100,DLCI=400,FrameRelayMapDLCI100Active,5,,,FrameRelayInverseARPandLMIOperation(cont.),Hello,Iam.,4,5,FrameRelayMapDLCI400Active,FrameRelayCloud,DLCI=100,DLCI=400,FrameRelayMapDLCI100Active,5,Hello,Iam.,6,,,FrameRelayInverseARPandLMIOperation(cont.),Keepalives,Keepalives,Hello,Iam.,4,5,FrameRelayMapDLCI400Active,FrameRelayCloud,DLCI=100,DLCI=400,FrameRelayMapDLCI100Active,5,Hello,Iam.,6,7,7,,,Rel.11.2Router,Rel.10.3Router,interfaceSerial1ipaddressencapsulationframe-relaybandwidth64,interfaceSerial1ipaddressencapsulationframe-relaybandwidth64frame-relaylmi-typeansi,HQ,Branch,ConfiguringBasicFrameRelay,InverseARPEnabledbydefaultDoesnotappearinconfigurationoutput,Rel.11.2Router,Rel.10.3Router,HQ,interfaceSerial1ipaddressencapsulationframe-relaybandwidth64,interfaceSerial1ipaddressencapsulationframe-relaybandwidth64frame-relaylmi-typeansi,Branch,ConfiguringBasicFrameRelay(cont.),DLCI=110IPaddress=/24,p1r1,DLCI=100IPaddress=/24,interfaceSerial1ipaddressencapsulationframe-relaybandwidth64frame-relaymapip110broadcast,HQ,Branch,ConfiguringaStaticFrameRelayMap,VerifyingFrameRelayOperation,Displaysline,protocol,DLCI,andLMIinformation,Router#showinterfaces0Serial0isup,lineprotocolisupHardwareisHD64570Internetaddressis/24MTU1500bytes,BW1544Kbit,DLY20000usec,rely255/255,load1/255EncapsulationFRAME-RELAY,loopbacknotset,keepaliveset(10sec)LMIenqsent19,LMIstatrecvd20,LMIupdrecvd0,DTELMIupLMIenqrecvd0,LMIstatsent0,LMIupdsent0LMIDLCI1023LMItypeisCISCOframerelayDTEFRSVCdisabled,LAPFstatedownBroadcastqueue0/64,broadcastssent/dropped8/0,interfacebroadcasts5Lastinput00:00:02,output00:00:02,outputhangneverLastclearingofshowinterfacecountersneverQueueingstrategy:fifoOutputqueue0/40,0drops;inputqueue0/75,0drops,DisplaysLMIinformation,Router#showframe-relaylmiLMIStatisticsforinterfaceSerial0(FrameRelayDTE)LMITYPE=CISCOInvalidUnnumberedinfo0InvalidProtDisc0InvaliddummyCallRef0InvalidMsgType0InvalidStatusMessage0InvalidLockShift0InvalidInformationID0InvalidReportIELen0InvalidReportRequest0InvalidKeepIELen0NumStatusEnq.Sent113100NumStatusmsgsRcvd113100NumUpdateStatusRcvd0NumStatusTimeouts0,VerifyingFrameRelayOperation(cont.),DisplaysPVCtrafficstatistics,VerifyingFrameRelayOperation(cont.),Router#showframe-relaypvc100PVCStatisticsforinterfaceSerial0(FrameRelayDTE)DLCI=100,DLCIUSAGE=LOCAL,PVCSTATUS=ACTIVE,INTERFACE=Serial0inputpkts28outputpkts10inbytes8398outbytes1198droppedpkts0inFECNpkts0inBECNpkts0outFECNpkts0outBECNpkts0inDEpkts0outDEpkts0outbcastpkts10outbcastbytes1198pvccreatetime00:03:46,lasttimepvcstatuschanged00:03:47,Displaystheroutemaps,eitherstaticordynamic,Router#showframe-relaymapSerial0(up):ipdlci100(0 x64,0 x1840),dynamic,broadcast,statusdefined,active,VerifyingFrameRelayOperation(cont.),ClearsdynamicallycreatedFrameRelaymaps,VerifyingFrameRelayOperation(cont.),Router#showframe-relaymapSerial0(up):ipdlci100(0 x64,0 x1840),dynamic,broadcast,statusdefined,activeRouter#clearframe-relay-inarpRouter#shframemapRouter#,DisplaysLMIdebuginformation,VerifyingFrameRelayOperation(cont.),Router#debugFramelmiFrameRelayLMIdebuggingisonDisplayingallFrameRelayLMIdataRouter#1w2d:Serial0(out):StEnq,myseq140,yourseen139,DTEup1w2d:datagramstart=0 xE008EC,datagramsize=131w2d:FRencap=0 xFCF103091w2d:007501010103028C8B1w2d:1w2d:Serial0(in):Status,myseq1401w2d:RTIE1,length1,type11w2d:KAIE3,length2,yourseq140,myseq1401w2d:Serial0(out):StEnq,myseq141,yourseen140,DTEup1w2d:datagramstart=0 xE008EC,datagramsize=131w2d:FRencap=0 xFCF103091w2d:007501010103028D8C1w2d:1w2d:Serial0(in):Status,myseq1421w2d:RTIE1,length1,type01w2d:KAIE3,length2,yourseq142,myseq1421w2d:PVCIE0 x7,length0 x6,dlci100,status0 x2,bw0,Star(HubandSpoke),FullMesh,PartialMesh,FrameRelaydefault:nonbroadcast,multiaccess(NMBA),SelectingaFrameRelayTopology,Problem:Broadcasttrafficmustbereplicatedforeachactiveconnection,RoutingUpdate,A,C,B,ReachabilityIssueswithRoutingUpdates,B,C,D,A,ResolvingReachabilityIssues,Solution:SplithorizoncancauseproblemsinNBMAenvironmentsSubinterfacescanresolvesplithorizonissuesAsinglephysicalinterfacesimulatesmultiplelogicalinterfaces,SubnetA,SubnetB,SubnetC,S0,PhysicalInterface,LogicalInterface,ConfiguringSubinterfaces,Point-to-PointSubinterfacesactasleasedlineEachpoint-to-pointsubinterfacerequiresitsownsubnetApplicabletohubandspoketopologiesMultipointSubinterfacesactasNBMAnetworksotheydonotresolvethesplithorizonissueCansaveaddressspacebecauseusessinglesubnetApplicabletopartial-meshandfull-meshtopology,A,s0.2,B,ConfiguringPoint-to-PointSubinterfaces,interfaceSerial0noipaddressencapsulationframe-relay!interfaceSerial0.2point-to-pointipaddress10