module1企業(yè)路由域快速部署協(xié)議原理與配置

PIM協(xié)議原理與配置組播報(bào)文發(fā)送給一組特定的接收者，這些接收者可能分布在網(wǎng)絡(luò)中的任意位置。為了實(shí)現(xiàn)組播報(bào)文正確、高效地轉(zhuǎn)發(fā)，組播路由器需要建立和維護(hù)組播路由表項(xiàng)。隨著多個(gè)組播路由協(xié)議的開發(fā)與應(yīng)用，人們漸漸感覺(jué)到，如果像單播路由一樣通過(guò)多種路由算法動(dòng)態(tài)生成組播路由，會(huì)帶來(lái)不同路由協(xié)議間在互相引入時(shí)操作繁瑣的問(wèn)題。PIM（ProtocolIndependentMulticast）直接利用單播路由表的路由信息進(jìn)行組播報(bào)文RPF檢查，創(chuàng)建組播路由表項(xiàng)，轉(zhuǎn)發(fā)組播報(bào)文。學(xué)完本課程后，您將能夠：了解組播轉(zhuǎn)發(fā)需求掌握PIM-DM的基本原理和配置掌握PIM-SM的基本原理和配置組播報(bào)文轉(zhuǎn)發(fā)需求PIM-DM的工作機(jī)制PIM-DM的局限性PIM-SM的工作機(jī)制路由器如何轉(zhuǎn)發(fā)組播報(bào)文路由器需要依據(jù)哪些信息進(jìn)行轉(zhuǎn)發(fā)：各接口所在網(wǎng)段有無(wú)潛在接收者。接收者需要接收哪些組的數(shù)據(jù)。人工配置上述信息存在一些問(wèn)題：實(shí)時(shí)性差。靈活性差。工作量大、易出錯(cuò)。MulticastPacketClientC（G1）SourceMulticastNetworkClientBClientA(G1)組播報(bào)文轉(zhuǎn)發(fā)需求PIM-DM的工作機(jī)制PIM-DM的局限性PIM-SM的工作機(jī)制PIM-DM基本概述采用“推（Push）模式”轉(zhuǎn)發(fā)組播報(bào)文。PIM-DM的關(guān)鍵任務(wù)：建立SPT（ShortestPathTree，最短路徑樹）。PIM-DM的工作機(jī)制：鄰居發(fā)現(xiàn)。擴(kuò)散與剪枝。狀態(tài)刷新。嫁接。斷言。PIM-DM鄰居發(fā)現(xiàn)使用Hello機(jī)制發(fā)現(xiàn)鄰居：選舉DR：RTARTBHello優(yōu)先級(jí)高的或者IP地址大的成為DR。HelloClientARTCRTDHelloHelloPIM-DM構(gòu)建SPT擴(kuò)散過(guò)程。RPF檢查。剪枝過(guò)程。ClientA(G1)ClientC（G1）SourceMulticastNetwork下游節(jié)點(diǎn)沒(méi)有組播成員，則向上進(jìn)行Prune。收到組播流，向下游進(jìn)行擴(kuò)散。RTCRTEClientB每個(gè)路由器都會(huì)創(chuàng)建（S,G）表項(xiàng)。RTARTDRTB狀態(tài)刷新周期性地刷新剪枝狀態(tài)。ClientA(G1)ClientC（G1）SourceMulticastNetworkStateRefreshRTCRTERTAClientBRTDRTBGraft機(jī)制新的組成員加入組播組后，快速得到組播報(bào)文。ClientA(G1)SourceMulticastNetworkGraft/GraftAckIGMP報(bào)告（G1）①②③RTCRTERTAClientBClientC（G1）RTDRTBAssert機(jī)制避免重復(fù)組播報(bào)文。MulticastPacketAssert消息ClientARTARTBRTCRTDMulticastNetwork同一網(wǎng)絡(luò)出現(xiàn)三份同樣的組播數(shù)據(jù)流。PIM-DM配置實(shí)現(xiàn)multicastrouting-enableinterfaceG0/0/0pimdminterfaceG0/0/1pimdmClientCSourcePIM-DMRTDG0/0/1G0/0/0G0/0/0G0/0/0G0/0/0G0/0/0G0/0/1G0/0/1G0/0/1G0/0/1G0/0/2G0/0/2RTARTBRTCRTEmulticastrouting-enableinterfaceG0/0/0pimdminterfaceG0/0/1pimdminterfaceG0/0/2pimdm同RTA配置同RTD配置同RTD配置ClientBClientAPIM-DM配置驗(yàn)證<RTD>displaypimrouting-tableVPN-Instance:publicnetTotal1(*,G)entry;1(S,G)entry(192.168.0.1,239.255.255.250)Protocol:pim-dm,Flag:ACTUpTime:00:00:09Upstreaminterface:GigabitEthernet0/0/0Upstreamneighbor:10.1.14.1RPFprimeneighbor:10.1.14.1Downstreaminterface(s)information:Totalnumberofdownstreams:11:GigabitEthernet0/0/1Protocol:pim-dm,UpTime:00:00:09,Expires:-<RTD>displaypimneighborVPN-Instance:publicnetTotalNumberofNeighbors=1NeighborInterfaceUptimeExpiresDr-PriorityBFD-Session10.1.14.1GE0/0/000:12:1900:01:161N組播報(bào)文轉(zhuǎn)發(fā)的需求PIM-DM的工作機(jī)制PIM-DM的局限性PIM-SM的工作機(jī)制PIM-DM的局限性PIM-DM適用于組播成員分布較為密集的園區(qū)網(wǎng)絡(luò)。PIM-DM的局限性：在組播成員分布較為稀疏的網(wǎng)絡(luò)中，組播流量的周期性擴(kuò)散會(huì)給網(wǎng)絡(luò)帶來(lái)較大負(fù)擔(dān)。組播報(bào)文轉(zhuǎn)發(fā)的需求PIM-DM的工作機(jī)制PIM-DM的局限性PIM-SM的工作機(jī)制PIM-SM基本概述使用“拉（Pull）模式”轉(zhuǎn)發(fā)組播報(bào)文。PIM-SM的關(guān)鍵任務(wù)：建立RPT（RendezvousPointTree，匯聚點(diǎn)樹也稱共享樹）。建立SPT（ShortestPathTree，最短路徑樹）。適用于組播成員分布較為稀疏的網(wǎng)絡(luò)環(huán)境。匯聚點(diǎn)RP（RendezvousPoint）充當(dāng)RPT樹的根節(jié)點(diǎn)。共享樹中的所有組播流量都經(jīng)過(guò)RP轉(zhuǎn)發(fā)給接收者。所有PIM路由器都要知道RP的位置。RPT及其建立過(guò)程思考：如果連接ClientA的路由器有兩臺(tái)，這兩臺(tái)路由器都會(huì)向RP發(fā)送（*，G）Join消息嗎？IGMP報(bào)告ClientARP①（*，G）Join②③RPTSourceClientB（*，G）條目在RPT沿途的路由器上生成。組播接收者側(cè)DR與組播源側(cè)DRClientASourcePIM-SMRP用戶端DR源端DR（*，G）JoinRegister單播Register發(fā)往RP。向RP發(fā)送（*，G）的Join。SPT的建立過(guò)程RP源端DR①②③③④Source④⑤⑤Register/RegisterStop第一個(gè)組播報(bào)文RPT(S,G)Join消息SPT⑥SPT建好之后，組播報(bào)文沿SPT到達(dá)RP。（*，G）與（S，G）條目關(guān)系模式類型使用場(chǎng)景PIM-DM（S，G）第一跳路由器到最后一跳路由器的SPT。PIM-SM（*，G）RP到最后一跳路由器的RPT。（S，G）源端DR到RP的SPT。（S，G）Switchover之后，從第一跳路由器到最后一跳路由器的SPT。ClientBPIM-SM的轉(zhuǎn)發(fā)樹SPT和RPT構(gòu)成組播報(bào)文的轉(zhuǎn)發(fā)路徑，存在哪些問(wèn)題？RPTClientARPSourceSPT非最優(yōu)轉(zhuǎn)發(fā)路徑Switchover機(jī)制RPTClientARPSPT①用戶端DR收到組播報(bào)文的速率超過(guò)閾值時(shí)，會(huì)向組播源發(fā)送（S，G）Join消息。(S,G)Join消息②形成新的SPT。③剪掉共享樹上的數(shù)據(jù)流。ClientBSourcePIM-SM配置實(shí)現(xiàn)multicastrouting-enableinterfaceG0/0/0pimsminterfaceG0/0/1pimsminterfaceG0/0/2pimsmpimstatic-rp4.4.4.4ClientARPSourceClientBG0/0/0G0/0/1G0/0/1G0/0/1G0/0/1G0/0/1G0/0/1G0/0/0G0/0/2G0/0/0G0/0/0G0/0/2G0/0/2G0/0/0G0/0/0multicastrouting-enableinterfaceG0/0/0pimsminterfaceG0/0/1pimsmpimstatic-rp4.4.4.4RTARTBRTCRTDRTERTF同RTA配置同RTA配置同RTB配置同RTB配置PIM-SM配置驗(yàn)證<RTF>displaypimrouting-tableVPN-Instance:publicnetTotal1(*,G)entry;0(S,G)entry(*,224.1.1.1)RP:4.4.4.4Protocol:pim-sm,Flag:WCUpTime:00:00:20Upstreaminterface:GigabitEthernet0/0/0Upstreamneighbor:10.1.46.4RPFprimeneighbor:10.1.46.4Downstreaminterface(s)information:Totalnumberofdownstreams:11:GigabitEthernet0/0/1Protocol:igmp,UpTime:00:00:20,Expires:-<RTB>displaypimneighborVPN-Instance:publicnetTotalNumberofNeighbors=3NeighborInterfaceUptimeExpiresDr-PriorityBFD-Session10.1.12.1GE0/0/000:04:0800:01:271N10.1.23.3GE0/0/100:01:2900:01:161N10.1.24.4GE0/0/200:03:1900:01:251N組播綜合實(shí)驗(yàn)ClientAClientBClientCRTARTBRTCRTDRTESWARTFSourceA如圖所示，要求在網(wǎng)絡(luò)中部署PIM-SM協(xié)議且以靜態(tài)方式指定RTB為RP。用戶側(cè)網(wǎng)絡(luò)配置IGMPv2協(xié)議，同時(shí)需要盡可能地降低用戶側(cè)網(wǎng)絡(luò)資源消耗，提高安全性。RTE和RTF連接接收者，要求在RTE和RP之間建立RPT。RTD連接重要的用戶網(wǎng)絡(luò)，當(dāng)用戶加入組播組238.1.1.1組后，需要馬上就能收到組播數(shù)據(jù)。RPPIM-SM配置實(shí)現(xiàn)(1)multicastrouting-enableinterfaceg0/0/0pimsminterfaceg0/0/1pimsminterfaceg0/0/2pimsmpimstatic-rp2.2.2.2RTD配置同RTEmulticastrouting-enableinterfaceg0/0/0pimsminterfaceg0/0/1pimsmpimstatic-rp2.2.2.2ClientAClientBClientCRTARTBRTCRTDRTESWARTFSourceAG0/0/0G0/0/0G0/0/0G0/0/0G0/0/0G0/0/0G0/0/1G0/0/1G0/0/1G0/0/1G0/0/1G0/0/2G0/0/2G0/0/2G1/0/0G0/0/1multicastrouting-enableinterfaceg0/0/0pimsm