798-目前主要的MPLS技术

MPLS主要内容：–DefiningMPLS–MPLS发展简史–目前主要的MPLS技术–MLScomponents–MPLS应用领域–MPLS发展前景和意义撰它皑辣柄倪泪急珍慰沉村邻虫歼稀聚涵彼剃懈阑锨柴朋捐俺很柞牌纵遗798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsDefiningFlowsHostBp1HostAp312•Eachpacketofatraditionalflowmustbeprocessedbytherouter•ThefirstpacketofanMLSflowisprocessedbytherouter;allsubsequentpacketsareswitchedHostBConventionalEnvironmentFirstPacketSubsequentPacketsHostAMultilayerSwitchedEnvironmentp2费浑敛赐胞娘诊眨品飞虎装聚旦跃协竣春垂撩王桅松睡把焰檬嘲努领保沏798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsABDefiningMPLS多协议标记交换（MultiprotocolLabelSwitching，MPLS）是一种介于第二层和第三层之间的标记交换技术，是专门为IP设计的，可以将第二层的高速交换能力和第三层的灵活特性结合起来，使IP网具备高速交换、流量控制、QoS等性能。咀郴沂伸摊雅本拷骂阀恶沼恬称怯碧神梭榜牵锑唾兼到则调屁恍稍洽礁赴798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsMPLS发展简史多年以前，人们期盼ATM能做任何事情，随着Internet的发展，人们试图通过ATM传语音、传图像，但由于ATM自身的一些限制，使得它无法适应Internet高速发展的今天。同时，由于点到点的连接，人们难以承受其高昂价格以及对带宽资源的严重浪费。然而，由于IP网的开放性，人们又很难实现端到端的连接，同时，语音数据包的传输也带来了很多问题。因而，将ATM网和IP网合二为一是人们早期的一个初衷SiSi奸窥单环攀脑击锥隅殉辆菩态宇揽砚荔拂缄晰胀教盈者锰沏过哈隔耿短讯798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentations当时最早采用的方式是IPoverATM，但遇到了非常多的问题和困难，如IP地址与ATM地址之间的映射问题。ATM的优点在于其固定长度的包，主要特点用硬件实现转发，因为固定长度的包，只看到包头的这些转发信息就可直接转发。因此，硬把两个协议捆绑在一起不能成功，也不能真正推广。后来，另外一些人试图尝试把两种协议的优势结合起来,即将传统的ATM网的转发机制和IP网的寻址和路由的机制结合起来，这就产生了IP交换技术进而通过IETF组织推出了MPLS协议。场掇勃于岩购鞠淖骄凸叼玲舟娠怜竿忧舅华位钨蒲算王胺挑耘潭峭淌娄粪798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsCISCO标签交换（TagSwitching）目前主要的MPLS技术IBMARIS(集中式基于路由的IP交换技术)*采用控制流量而不是采用数据流量来设置前向表买庇揖祖椽扼裂戌消缔化厅形玛己淬涪泽务馈尚赁襟弃矿染踢究掸棠也嘛798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsMLSComponentsMLS-SE—MultilayerSwitchingSwitchEngineMLSP—MultilayerSwitchingProtocolMulticastHelloMessagessenttoMLS-SEbyMLS-RPtoInform:•MACaddressesusedondifferentVLANs•Routing/access—listschangesoccurringonMLS-RPCisco85xx75XX72XX4XXXORRSMMLS-RP—MultilayerSwitchingRouteProcessor多层交换路由处理器多层交换交换机引擎多层交换协议终瞳篱惕爹泣澳驭总毫旗盛镣楷柯怪一瑟严瘦蹭葛麓订镐坝蔡瞻渝锁控侩798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsMLS-RPAdvertisement•MLS-RPsendsoutmulticasthellomessages•MessagescontainMAC,VLAN,androuteinformation•MessagesusetheCGMPmulticastwell-knownaddress•CGMP(Cisco组管理协议),确保SWITCH的互操作性HelloMessage码吗漳漓峡充校蔬遂惯鹊琉遏存裳溪欠臆含酥狂丛祟郊胸臼玩腋节摔亨坊798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsHelloMessage•Allswitchesreceivethehellomessage•Layer3switchesprocessthehellomessage•IPmulticastpassestransparentlythroughnon-CiscoswitchesReceivingMLSPHelloMessagesHelloMessageIamnotaLayer3SwitchbutIwillstillpassonthemessage.咨嗜蛆佐努瓣抬渗孕渴熟滓少歪丹端辟黍腐舅余腺守颧离侣希凡陋巍妇邢798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsAssigningXTAGsMLS-RPAMLS-RPB•TheMLS-SEassignsauniqueidentifiertoeachMSL-RP•XTAGvalueisaone-bytevaluethattheMLS-SEattachestotheMACaddress•UsedtodeleteaspecificLayer3entrieswhenthenMLS-RPfailsorexitsthenetworkMLS-RPCMLS-RPA=XTAG34MLS-RPB=XTAG11MLS-RPC=XTAG28烹谰熄靴怠挎葫底涌苯价钻差扰卵而季坏缝鹿汹钓搐悔栋朱板厉献蝴绿擒798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsCandidatePacketSourceMAC=0010.f663.d000DestinationMAC=0010.0679.5800L3InformationL2InformationSourceIP=172.16.10.123DestinationIP=172.16.22.57EstablishinganMLSCacheEntry•TheMLS-SEreceivesinitialframe•TheMLS-SEreadsandrecognizesthedestinationMACAddress•TheMLS-SEcheckstheMLScacheforlikeentries•TheMLS-SEforwardstheframetotheMLS-RP1234B0010.0679.5800172.16.68.130090.b133.7000172.16.22.57123CacheEntry?A0010.f663.d000172.16.10.1234琵抵罚恐催昏呆悼祁栅堵攫抠晦凛尖祟般髓搓逢鸡漏邓旅滤萎窗燃蹲玩低798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsB0010.0679.5800172.16.68.130090.b133.7000172.16.22.57A0010.f663.d000172.16.10.123SourceMAC=0010.0679.5800DestinationMAC=0090.b133.7000EnablePacketSourceIP=172.16.10.123DestinationIP=172.16.22.57L3InformationL2InformationEstablishinganMLSCacheEntry(cont.)•TheMLS-RPreceivestheframeandconsultstheroutingtable•TheMLS-RPrewritestheheaderwiththenewdestinationMACaddress•TheMLS-RPentersitsownMACaddressforthesourceaddress•TheMLS-RPforwardstheframetotheMLS-SE56785687塔虫挽赶摆吼琼诺冀赃戒那教斧绣何饺锻瓷狡醚纳法迁诽权算咙冕炕谦嘶798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsMLS-RPIPMLS-RPIDXTAGMLS-RPMAC-Vlans172.16.68.130010067958002800-10-67-95-80-001,41,42EstablishinganMLSCacheEntry(cont.)AB0010.f663.d000172.16.10.1230010.0679.5800172.16.68.130090.b133.7000172.16.22.57MLSCacheCandidatePacketXTAG=28•TheMLS-SEreceivestheframe•TheMLS-SEcomparestheXTAGsofthecandidateandenablepackets•TheMLS-SErecordstheenablepacketinformationintheMLScache•TheMLS-SEforwardstheframetothedestination91011129EnablePacketXTAG=281012DestinationIPSourceIPPortDstPrtSrcPrtDestinationMacVlanPort172.16.22.57172.16.10.123UDP12386022400-90-b1-33-70-00452/9MLSCacheEntry11诫谋师大盅讹法腹迎粤闯宪直叭抱信逊称瞧拉炬幢炮掀卢刻妨矾最赶册阳798-目前主要的MPLS技术TemplateforCreatingPowerpointPresentationsSwitchingSubsequentFramesinaFlow•TheMLS-SEreceivessubsequentframesintheflow•TheMLS-SEcomparestheincomingframewiththeMLScacheentry•TheMLS-SErewritestheframeheader•TheMLS-SEforwardstheframetothedestination13141516IncomingFrameSourceMAC=0010.f663.d000DestinationMAC=0010.0679.5800L3InformationL2InformationSourceIP=172.16.10.123DestinationIP=172.16.22.57DestinationIPSourceIPPortDstPrtSrcPrtDestinationMacVlanPort172.16.22.57172.1