网络技术培训系列课程：路由技术-各种路由协议路由汇总方法分析

1各种路由协议路由汇总方法分析2学习目标掌握各种路由协议路由汇总的配置命令掌握各种路由协议路由汇总的特性3课程内容第一章RIP路由汇总第二章OSPF路由汇总第三章BGP路由汇总34第一章RIP路由汇总RIP路由汇总配置命令接口下面配置汇总命令interfaceFastEthernet0/0.12encapsulationdot1Q12ipaddress9.9.12.1255.255.255.0ipsummary-addressrip192.168.1.0255.255.255.240R1R2R3Lo0:192.168.1.1/32RIPinterfaceFastEthernet0/0.23encapsulationdot1Q23ipaddress9.9.23.2255.255.255.0ipsummary-addressrip192.168.1.0255.255.255.05第一章RIP路由汇总路由汇总的结果R2和R3的路由表r2#shiproute….2.0.0.0/32issubnetted,1subnetsC2.2.2.2isdirectlyconnected,Loopback09.0.0.0/24issubnetted,2subnetsC9.9.12.0isdirectlyconnected,FastEthernet0/0.12C9.9.23.0isdirectlyconnected,FastEthernet0/0.23

192.168.1.0/28issubnetted,1subnetsR192.168.1.0[120/1]via9.9.12.1,00:00:19,FastEthernet0/0.12r3#shiproute…9.0.0.0/24issubnetted,2subnetsR9.9.12.0[120/1]via9.9.23.2,00:00:00,FastEthernet0/0.23C9.9.23.0isdirectlyconnected,FastEthernet0/0.23R192.168.1.0/24[120/2]via9.9.23.2,00:00:00,FastEthernet0/0.236第一章RIP路由汇总路由汇总的结果R1的路由表r1#shiproute…9.0.0.0/24issubnetted,2subnetsC9.9.12.0isdirectlyconnected,FastEthernet0/0.12R9.9.23.0[120/1]via9.9.12.2,00:00:08,FastEthernet0/0.12192.168.1.0/32issubnetted,1subnetsC192.168.1.1isdirectlyconnected,Loopback1R1并没有产生下一跳指向Null0接口的192.168.1.0/24的汇总路由7第一章RIP路由汇总路由汇总的结果R1的RIP数据库r1#shipripdatabase9.0.0.0/8auto-summary9.9.12.0/24directlyconnected,FastEthernet0/0.129.9.23.0/24[1]via9.9.12.2,00:00:06,FastEthernet0/0.12192.168.1.0/24auto-summary192.168.1.0/28int-summary//数据库中关于手动汇总路由的标记192.168.1.1/32directlyconnected,Loopback18第一章RIP路由汇总RIP路由汇总的相关注意事项进行手动汇总之前必须关闭自动汇总noauto-summary汇总可以在任意一台路由器上进行汇总路由的掩码必须大于或等于主类网络掩码r1(config-subif)#ipsummary-addressrip192.168.0.0255.255.0.0Summarymaskmustbegreaterorequaltomajornet9第一章RIP路由汇总RIP路由汇总的相关注意事项在通告汇总路由的路由器上创建指向Null0接口的汇总路由根据实际情况进行配置r1(config)#iproute192.168.1.0255.255.255.0null010课程内容第一章RIP路由汇总第二章OSPF路由汇总第三章BGP路由汇总1011第二章OSPF路由汇总OSPF路由汇总的控制点ABR将1/2类LSA转换为3类LSA时,可对产生的3类LSA进行汇总通告ASBR将外部LSA通告进自治系统内时,可对这些外部LSA进行汇总通告12第二章OSPF路由汇总ABR路由汇总配置命令R1R2R3R4area1area0area2routerospf1area1range172.9.0.0255.255.0.0Lo0:172.9.0.1/32172.9.12.0/2413第二章OSPF路由汇总ABR路由汇总结果R3、R4的路由表r3#shipro…OIA172.9.0.0/16[110/2]via9.9.23.2,00:14:24,FastEthernet0/0.23r4#shipro…OIA172.9.0.0/16[110/3]via192.9.34.3,00:14:19,FastEthernet0/0.3414第二章OSPF路由汇总ABR路由汇总结果R2的数据库没汇总之前的数据库汇总后的区别ABR不再产生明细的3类LSA

SummaryNetLinkStates(Area0)LinkIDADVRouterAgeSeq#Checksum172.9.0.09.9.0.213240x800000010x00BCB5

SummaryNetLinkStates(Area0)LinkIDADVRouterAgeSeq#Checksum172.9.0.19.9.0.270x800000010x00BCB3172.9.12.09.9.0.270x800000010x00382E15第二章OSPF路由汇总ABR路由汇总结果R2的路由表自动产生下一跳为Null0接口的汇总路由r2#shipro…172.9.0.0/16isvariablysubnetted,3subnets,3masksO172.9.0.1/32[110/2]via172.9.12.1,00:00:46,FastEthernet0/0.12O172.9.0.0/16isasummary,00:00:46,Null0C172.9.12.0/24isdirectlyconnected,FastEthernet0/0.129.0.0.0/8isvariablysubnetted,3subnets,2masksC9.9.0.2/32isdirectlyconnected,Loopback0O9.9.0.3/32[110/2]via9.9.23.3,00:00:46,FastEthernet0/0.23…16第二章OSPF路由汇总ABR路由汇总结果产生Null0接口汇总路由的意义R1R2R3R4area1area0area2Lo0:172.9.0.1/32汇总路由172.9.0.0/16出口R3:default-informaionoriginate默认路由R2不产生Null0接口汇总路由17第二章OSPF路由汇总ABR路由汇总结果产生Null0接口汇总路由的意义R1R2R3R4area1area0area2Lo0:172.9.0.1/32访问不存在的一个地址172.9.0.2的数据R2上没有相应的路由，于是按照默认路由转发给R3R3上面存在R2通告的172.9.0.0/16的汇总路由，于是转发回给R2…直至TTL=0，报文被丢弃，其中一台设备返回TTL超时18第二章OSPF路由汇总ABR路由汇总相关注意事项汇总的条件ABR仅在将1/2类LSA转换为3类LSA时，可以进行汇总如果1/2类LSA转换后的3类LSA中的网络号不在汇总网段范围内，则仍以精确的3类LSA通告。汇总路由其他参数r2(config-router)#area1range172.9.0.0255.255.0.0?advertiseAdvertisethisrange(default)costUserspecifiedmetricforthisrange//调整汇总的3类LSA的Metricnot-advertiseDoNotAdvertisethisrange//抑制产生该汇总的3类LSA以及相关明细3类LSA19第二章OSPF路由汇总ASBR路由汇总配置命令R1R2R3R4RIParea0area2routerospf1summary-address172.9.0.0255.255.0.0redistributeripsubnetsLo0:172.9.0.1/32172.9.12.0/2420第二章OSPF路由汇总ASBR路由汇总结果R3的路由表r3#shipro…OE2172.9.0.0/16[110/20]via9.9.23.2,00:03:09,FastEthernet0/0.239.0.0.0/8isvariablysubnetted,3subnets,2masksO9.9.0.2/32[110/2]via9.9.23.2,00:03:09,FastEthernet0/0.23C9.9.0.3/32isdirectlyconnected,Loopback0C9.9.23.0/24isdirectlyconnected,FastEthernet0/0.23192.9.0.0/32issubnetted,1subnetsO192.9.0.4[110/2]via192.9.34.4,00:03:09,FastEthernet0/0.34C192.9.34.0/24isdirectlyconnected,FastEthernet0/0.3421第二章OSPF路由汇总ASBR路由汇总结果R4的路由表r4#shipro…OE2172.9.0.0/16[110/20]via192.9.34.3,00:04:33,FastEthernet0/0.349.0.0.0/8isvariablysubnetted,3subnets,2masksOIA9.9.0.2/32[110/3]via192.9.34.3,00:04:35,FastEthernet0/0.34OIA9.9.0.3/32[110/2]via192.9.34.3,00:04:43,FastEthernet0/0.34OIA9.9.23.0/24[110/2]via192.9.34.3,00:04:39,FastEthernet0/0.34192.9.0.0/32issubnetted,1subnetsC192.9.0.4isdirectlyconnected,Loopback0C192.9.34.0/24isdirectlyconnected,FastEthernet0/0.3422第二章OSPF路由汇总ASBR路由汇总结果R2的路由表r2#shipro…172.9.0.0/16isvariablysubnetted,3subnets,3masksR172.9.0.1/32[120/1]via172.9.12.1,00:00:20,FastEthernet0/0.12O172.9.0.0/16isasummary,00:08:20,Null0C172.9.12.0/24isdirectlyconnected,FastEthernet0/0.129.0.0.0/8isvariablysubnetted,3subnets,2masksC9.9.0.2/32isdirectlyconnected,Loopback0O9.9.0.3/32[110/2]via9.9.23.3,00:07:17,FastEthernet0/0.23C9.9.23.0/24isdirectlyconnected,FastEthernet0/0.23192.9.0.0/32issubnetted,1subnetsOIA192.9.0.4[110/3]via9.9.23.3,00:07:06,FastEthernet0/0.23OIA192.9.34.0/24[110/2]via9.9.23.3,00:07:11,FastEthernet0/0.2323第二章OSPF路由汇总ASBR路由汇总相关注意事项汇总的条件重发布路由生成的5类LSA中的网络号不在汇总网段范围内，则仍以精确的5类LSA通告。汇总路由其他参数r2(config-router)#summary-address172.9.0.0255.255.0.0?not-advertiseDonotadvertisewhentranslatingOSPFtype-7LSAtagSettagmetricSetmetric<cr>24第二章OSPF路由汇总ASBR路由汇总其他方法R1R2R3R4RIParea0area2access-list1permit172.9.0.0route-mapStatic2OSPFpermit10matchipaddress1iproute172.9.0.0255.255.0.0Null0routerospf1redistributestaticsubnetsroute-mapStatic2OSPFLo0:172.9.0.1/32172.9.12.0/2425课程内容第一章RIP路由汇总第二章OSPF路由汇总第三章BGP路由汇总2526第三章BGP路由汇总BGP路由汇总方法:手动汇总首先创建下一跳为Null0的静态汇总路由在BGP进程下面使用network命令引入该汇总路由自动汇总在BGP进程下面使用aggregate-address命令27第三章BGP路由汇总BGP路由手动汇总配置方法R1R2R3OSPFIBGPorEBGPLo0:172.9.0.1/32172.9.12.0/24iproute172.9.0.0255.255.0.0Null0routerbgp1network172.9.0.0mask255.255.0.0neighbor9.9.0.3remote-as1neighbor9.9.0.3update-sourceLoopback0noauto-summary28第三章BGP路由汇总BGP路由手动汇总R3的路由表r3#shipbBGPtableversionis2,localrouterIDis9.9.0.3Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>i172.9.0.09.9.0.201000ir3#shipro…B172.9.0.0/16[200/0]via9.9.0.2,00:13:489.0.0.0/8isvariablysubnetted,3subnets,2masksR9.9.0.2/32[120/1]via9.9.23.2,00:00:10,FastEthernet0/0.23C9.9.0.3/32isdirectlyconnected,Loopback0C9.9.23.0/24isdirectlyconnected,FastEthernet0/0.2329第三章BGP路由汇总BGP路由自动汇总通告汇总路由的条件必须事先在BGPTable中存在明细的BGP路由,才能够在配置汇总命令后，通告出汇总路由。R1R2R3OSPFIBGPorEBGPLo0:172.9.0.1/32172.9.12.0/24routerbgp1aggregate-address172.9.0.0255.255.0.0R2不会通告汇总的BGP路由172.9.0.0/1630第三章BGP路由汇总BGP路由自动汇总通告汇总路由的条件必须事先在BGPTable中存在明细的BGP路由,才能够在配置汇总命令后，通告出汇总路由。R1R2R3OSPFIBGPorEBGPLo0:172.9.0.1/32172.9.12.0/24routerbgp1aggregate-address172.9.0.0255.255.0.0

redistributeospf1matchinternalexternal1external2R2通告汇总的BGP路由172.9.0.0/1631第三章BGP路由汇总BGP路由自动汇总配置命令及关键字r2(config)#routerbgp1r2(config-router)#aggregate-address172.9.0.0255.255.0.0?advertise-mapSetconditiontoadvertiseattributeas-setGenerateASsetpathinformationattribute-mapSetattributesofaggregatenlriNlriaggregateappliestoroute-mapSetparametersofaggregate

summary-onlyFiltermorespecificroutesfromupdatessuppress-mapConditionallyfiltermorespecificroutesfromupdates32第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍summary-only:FiltermorespecificroutesfromupdatesR1R2R3R6(AS6)AS1AS2AS3172.9.2.0/24172.9.3.0/24R4172.9.4.0/24R5routerbgp1aggregate-address172.9.0.0255.255.0.0没有关联summary-only关键字，R1会向BGPPeer既通告明细路由，也会通告汇总路由，并且也会自动生成Null0接口的汇总路由33第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍summary-only:FiltermorespecificroutesfromupdatesR1R2R3R6(AS6)AS1AS2AS3172.9.2.0/24172.9.3.0/24R4172.9.4.0/24R5routerbgp1aggregate-address172.9.0.0255.255.0.0summary-only关联summary-only关键字后，R1仅向BGPPeer通告汇总路由34第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍summary-only:Filtermorespecificroutesfromupdatesr1#shipbBGPtableversionis8,localrouterIDis9.9.0.1Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.0.00.0.0.032768is>172.9.2.0/249.9.12.2002is>172.9.3.0/249.9.13.3003is>i172.9.4.0/249.9.14.401000i所有的明细路由被抑制，标记为小s35第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍summary-only:Filtermorespecificroutesfromupdates从R6的BGP表看出，R1在通告汇总路由时仅携带了自己的AS号，并没有携带明细路由的AS号。r6#shipbBGPtableversionis8,localrouterIDis9.9.0.6Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.0.09.9.16.1001i36第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍summary-only:Filtermorespecificroutesfromupdatesr1#shipb172.9.0.0BGProutingtableentryfor172.9.0.0/16,version7Paths:(1available,best#1,tableDefault-IP-Routing-Table)Advertisedtononpeer-grouppeers:9.9.12.29.9.13.39.9.14.49.9.15.59.9.16.6Local,(aggregatedby19.9.0.1)0.0.0.0from0.0.0.0(9.9.0.1)OriginIGP,localpref100,weight32768,valid,aggregated,local,atomic-aggregate,bestaggregated:标识该路由为一条聚合路由atomic-aggregate:标识明细路由的详细属性信息丢失37第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set:GenerateASsetpathinformationR1R2R3R6(AS6)AS1AS2AS3172.9.2.0/24172.9.3.0/24R4172.9.4.0/24R5routerbgp1aggregate-address172.9.0.0255.255.0.0as-setsummary-only关联as-set关键字后，R1通告的汇总路由会继承明细路由的部分路径属性38第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set:GenerateASsetpathinformationas-set能够继承的明细路由路径属性包括:As-path:将收到的所有明细路由的as号都放置在{}中Origin:继承最差的origin属性Community:继承所有明细路由的community39第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set:GenerateASsetpathinformation使用as-set关键字后，R1通告的汇总路由的atomic-aggregate属性消失r1#shipb172.9.0.0BGProutingtableentryfor172.9.0.0/16,version13Paths:(1available,best#1,tableDefault-IP-Routing-Table)Advertisedtononpeer-grouppeers:9.9.12.29.9.13.39.9.14.49.9.15.59.9.16.6{2,3},(aggregatedby19.9.0.1)0.0.0.0from0.0.0.0(9.9.0.1)OriginIGP,localpref100,weight32768,valid,aggregated,local,best40第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set:GenerateASsetpathinformationr6#shipbBGPtableversionis4,localrouterIDis9.9.0.6Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.0.09.9.16.1001{2,3}i在选路时，{}只算一个as号。如果收到的路由的as-path的大括号中，有自己的as号，仍然执行环路预防。41第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set可能会存在的问题可以看到R1向R3通告了汇总路由，携带的AS号存在{2,3}r1#shipbnei9.9.13.3advertised-routesBGPtableversionis28,localrouterIDis9.9.0.1Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.0.00.0.0.010032768{2,3}i42第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set可能会存在的问题R3收到R1通告的汇总路由时，由于执行AS-Path环路检查机制，在收到的汇总路由的AS-Path中看到了{2,3}，所以不接收该汇总路由，同时又由于summary-only的作用,R1也不会通告明细路由给R3r3#shipbBGPtableversionis10,localrouterIDis9.9.0.3Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.3.0/240.0.0.0032768i43第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set可能会存在的问题的解决办法R1对R3使用unsuppress-map，配置如下access-list1permit172.9.4.0access-list1permit172.9.2.0route-mapABCpermit10matchipaddress1routerbgp1aggregate-address172.9.0.0255.255.0.0as-setsummary-onlyneighbor9.9.13.3unsuppress-mapABCR1将通告Route-mapABC定义的明细路由给特定的邻居R3，虽然这些明细路由已经被抑制44第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set可能会存在的问题的解决办法R1通告给R3的路由r1#shipbnei9.9.13.3advertised-routesBGPtableversionis28,localrouterIDis9.9.0.1Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.0.00.0.0.010032768{2,3}is>172.9.2.0/249.9.12.2002is>i172.9.4.0/249.9.14.401000i45第三章BGP路由汇总BGP路由自动汇总各种关键字的作用介绍as-set可能会存在的问题的解决办法R3接收路由r3#shipbBGPtableversionis12,localrouterIDis9.9.0.3Statuscodes:ssuppressed,ddamped,hhistory,*valid,>best,i-internal,rRIB-failure,SStaleOrigincodes:i-IGP,e-EGP,?-incompleteNetworkNextHopMetricLocPrfWeightPath*>172.9.2.0