IP路由高级技术.ppt
IP路由协议（三）路由协议（三）NE实验室，2008西安邮电学院1/27/20231主要内容主要内容l描述OSPF多区域互联和寻址时面临的问题l解释不同类型的区域,routers,和 LSA之间的区别l解释 OSPF 如何支持 VLSMl解释 OSPF 在多区域中如何支持路由汇总l能够正确配置一个多区域的OSPF网络1/27/20232 2000,Cisco Systems,Inc.5-3多区域多区域OSPF创建创建1/27/20233维护大型维护大型 OSPF网络的问题网络的问题 My routing table is too big,I am running low on memory.The SPF is running toooften for me to route.I am only receivingLSAs,no data.OSPFOSPFOSPFOSPFOSPF1/27/20234Area 0Area 1Area 2Autonomous Systeml一个自治系统由多个区域组成l最小化路由更新产生的业务量解决方案解决方案:OSPF分层路由分层路由1/27/20235OSPF 多区域网络的组成成分多区域网络的组成成分RoutersLSAsInternalInternalABRABRASBRASBRBackboneBackboneType 1Type 2Type 3/4Type 5afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713Area 0I am a backbone.Area 2I am a stub.Area 1I am standard.Areas1/27/20236ExternalASOSPFOSPF路由器的类型路由器的类型路由器的类型路由器的类型InternalRouters Area 1Area 2Backbone Area 0InternalRouters 1/27/20237ExternalASOSPFOSPF路由器的类型路由器的类型路由器的类型路由器的类型InternalRouters Area 1Area 2Backbone/InternalRouters Backbone Area 0InternalRouters 1/27/20238ExternalASOSPFOSPF路由器的类型路由器的类型路由器的类型路由器的类型InternalRouters Area 1Area 2Backbone/InternalRouters ABR 和和BackboneRouter Backbone Area 0ABR 和和BackboneRouter InternalRouters 1/27/20239ExternalASInternalRouters Backbone/InternalRouters ABR 和和BackboneRouter ABR 和和 BackboneRouter InternalRouters ASBR 和和Backbone RouterOSPFOSPF路由器的类型路由器的类型路由器的类型路由器的类型Area 1Area 2Backbone Area 01/27/202310Link-State Advertisements的类型的类型lType 1:Router link entrylType 2:Network link entrylType 3 and 4:Summary link entrylType 5:AS external link entry1/27/202311OSPF链路状态数据库中的链路状态数据库中的LSARouterArea 1Area 0NetworkSummaryExternalABRABRDRDRrouter#show ip ospf databaseOSPFRouterwithID(10.64.0.1)(ProcessID1)RouterLinkStates(Area1)LinkIDADVRouterAgeSeq#ChecksumLinkcount10.1.2.110.1.2.16510 x800000050 xD4824NetLinkStates(Area1)LinkIDADVRouterAgeSeq#Checksum10.64.0.110.64.0.15380 x800000020 xAD9ASummaryNetLinkStates(Area1)LinkIDADVRouterAgeSeq#Checksum10.2.1.010.2.1.24390 x800000020 xE6F8ASBRASBRExternalAS1/27/202312区域的类型区域的类型区域的类型区域的类型骨干区负责互联骨干区负责互联;它接收所有的它接收所有的 LSAs.Backbone Area 01/27/202313Stub Area不接受外部不接受外部LSAs.区域的类型区域的类型区域的类型区域的类型骨干区负责互联骨干区负责互联;它接收所有的它接收所有的 LSAs.Backbone Area 01/27/202314Totally StubbyArea不接受外部路由，不接受外部路由，也不接收也不接收 区域间区域间汇总汇总 LSAs.Stub Area不接受外部不接受外部LSAs.区域的类型区域的类型区域的类型区域的类型Backbone Area 0骨干区负责互联骨干区负责互联;它接收所有的它接收所有的 LSAs.1/27/202315 2000,Cisco Systems,Inc.5-16OSPF多区域工作原理多区域工作原理1/27/202316多区域网络中的分组转发多区域网络中的分组转发BBoneInternalInternalABR2ABR1Area 50Data到到 ABR1到到 Backbone到到 ABR2到到 目的网络目的网络Area 1Area 0afadjfjorqpoeru395474390707131/27/202317洪泛洪泛洪泛洪泛 LSUs LSUs 到多个区域到多个区域到多个区域到多个区域 BBoneBBoneInternalInternalABR2ABR2ABR1ABR1InternalInternalType 1afadjfjorqpoeru39547439070713Area 1Area 0Area 50 Stub1/27/202318洪泛洪泛洪泛洪泛 LSUs LSUs 到多个区域到多个区域到多个区域到多个区域BBoneBBoneInternalInternalABR2ABR2ABR1ABR1InternalInternalType 3Type 1afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713Type 3afadjfjorqpoeru39547439070713Area 1Area 0Area 50 Stub1/27/202319Type 5afadjfjorqpoeru39547439070713Type 5DefaultArea 1Area 0BBoneBBoneInternalInternalABR2ABR2ABR1ABR1Area 50 StubInternalInternalRIPType 3Type 3Type 1afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713洪泛洪泛洪泛洪泛 LSUs LSUs 到多个区域到多个区域到多个区域到多个区域1/27/202320洪泛洪泛洪泛洪泛 LSUs LSUs 到多个区域到多个区域到多个区域到多个区域(cont.)(cont.)Routing TableInter-Area RoutesIntra-Area RoutesExternal(Non-OSPF Routes)Area 1Area 1Area 0Area 1RIP1/27/202321 2000,Cisco Systems,Inc.5-22Virtual Links 简介简介1/27/202322l其它区域必须与骨干区直连lVirtual links 提供一条到骨干区的路径l应尽可能避免配置Virtual links 骨干区域的要求骨干区域的要求Area 3Area 1Area 2Virtual LinkArea 0(Backbone)Transit AreaArea 31/27/202323remoterouter#showipospfinterfaceethernet0remoterouter#showipospfinterfaceethernet0Ethernet0isup,lineprotocolisupEthernet0isup,lineprotocolisupInternetAddress10.64.0.2/24,Area0InternetAddress10.64.0.2/24,Area0ProcessID1,RouterID10.64.0.2,NetworkTypeBROADCAST,Cost:10ProcessID1,RouterID10.64.0.2,NetworkTypeBROADCAST,Cost:10TransmitDelayis1sec,StateDR,Priority1TransmitDelayis1sec,StateDR,Priority1配置配置 Virtual Links创建 virtual linkRouter(config-router)#area area-id virtual-link router-id1/27/202324OSPF Virtual Link 配置实例配置实例R2:R2:routerospf63routerospf63network10.3.0.00.0.0.255area1network10.3.0.00.0.0.255area1network10.7.0.00.0.0.255area3network10.7.0.00.0.0.255area3R1:R1:routerospf100routerospf100network10.2.3.00.0.0.255area0network10.2.3.00.0.0.255area0network10.3.2.00.0.0.255area1network10.3.2.00.0.0.255area1 Router IDArea 3Area 0Area 1Router IDR1R21/27/202325 2000,Cisco Systems,Inc.5-26配置实例配置实例1/27/202326 2000,Cisco Systems,Inc.5-27多区域多区域OSPF 的配置的配置1/27/202327OSPF ABR配置配置 E0E0 S0S1A AB BC CABRinterfaceEthernet0interfaceEthernet0!routerospf77routerospf77network10.0.0.00.255.255.255area0network10.0.0.00.255.255.255area0Area 1Area 0interfaceEthernet0interfaceEthernet0!interfaceSerial0interfaceSerial0routerospf50routerospf50network10.2.1.20.0.0.0area1network10.2.1.20.0.0.0area1network10.64.0.20.0.0.0area0network10.64.0.20.0.0.0area01/27/202328DefaultDefaultSummaryDefaultStub 和和Totally Stubby 区域区域Area 1Totally StubbyArea 0InternalInternalABR2ABR2ABR1ABR1Area 50StubSummaryExternalExternalInternalNon-CiscoRouterBBoneBBoneSummaryRIPASBRASBRafadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru39547439070713afadjfjorqpoeru395474390707131/27/202329l典型的只有一个出口点.l内部不允许有ASBRl不能是 骨干区0l不允许Virtual linksStub 和和Totally Stubby 区域的区域的 限限制制单出口点单出口点Area 2R3R3R4R4ExternalASX X1/27/202330l建立一个 stub 区域l指定 发往stub 区域缺省路由的costRouter(config-router)#area area-id stub no-summary Router(config-router)#area area-id default-cost cost配置配置 Stub 和和 Totally Stubby 区区1/27/202331OSPF Stub 区配置举例区配置举例Area 0 Stub Area 2 S0S0E0R3#R3#interfaceEthernet0interfaceEthernet0interfaceSerial0interfaceSerial0routerospf100routerospf100network192.168.14.00.0.0.255area0network192.168.14.00.0.0.255area0network192.168.15.00.0.0.255area2network192.168.15.00.0.0.255area2area2stubarea2stubR4#R4#interfaceSerial0interfaceSerial0routerospf15routerospf15network192.168.15.00.0.0.255area2network192.168.15.00.0.0.255area2area2stubarea2stubExternalASR4R4R3R31/27/202332R4#R4#routerospf15routerospf15network192.168.15.00.0.0.255area2network192.168.15.00.0.0.255area2area2stubarea2stubOSPF Totally Stubby 区配置区配置R3#R3#routerospf100routerospf100network192.168.14.00.0.0.255area0network192.168.14.00.0.0.255area0network192.168.15.00.0.0.255area2network192.168.15.00.0.0.255area2area2stubno-summaryarea2stubno-summaryArea 0 S0S0E0ExternalASR4R4R3R3Totally Stubby Area 2 1/27/202333l减小路由表的条目l限制拓扑改变的影响范围l减少 LSA的数目支持支持 路由汇总路由汇总Area 0 BackboneABRsArea 1汇总汇总x x1/27/202334支持支持 VLSMlOSPF 携带 subnet 掩码信息l使用分层地址结构1/27/202335l区域间(IA)链路汇总消息携带掩码信息l一项代表多个子网 subnets使用路由汇总使用路由汇总B 的的Routing Table发往路由器发往路由器C的的LSAsArea 1Area 0ABR汇总汇总BBAACC1/27/202336l在ABR上合并 内部路由 l在 ASBR合并外部路由Router(config-router)#area area-id range address maskRouter(config-router)#summary-address address mask not-advertise tag tag配置路由汇总配置路由汇总1/27/202337路由汇总配置举例路由汇总配置举例R2R2#R2#routerospf100routerospf100network172.16.64.1network172.16.64.10.0.0.0area20.0.0.0area2network172.16.127.10.0.0.0area0network172.16.127.10.0.0.0area0R1#R1#routerospf100routerospf100network172.16.32.10.0.0.0area1network172.16.32.10.0.0.0area1network172.16.96.10.0.0.0area0network172.16.96.10.0.0.0area0area0range172.16.96.0255.255.224.0area0range172.16.96.0255.255.224.0area1range172.16.32.0255.255.224.0area1range172.16.32.0255.255.224.0255.255.255.0 Area 2255.255.255.0 255.255.255.0 Area 1Interface Addresses(255.255.255.0 Mask)Interface Addresses(255.255.255.0 Mask)R1R1R2R2Area 0 1/27/202338 2000,Cisco Systems,Inc.5-39OSPF配置验证配置验证1/27/202339show ip ospf 命令命令显示显示 自治域内的自治域内的ABRs 显示显示 virtual link的状态的状态显示路由器连接的每个区域的统计信息显示路由器连接的每个区域的统计信息显示显示 OSPF 数据库的内容数据库的内容show ip ospf process-idRouter#show ip ospf virtual-linksRouter#show ip ospf databaseRouter#show ip ospf border-routersRouter#1/27/202340总结总结l解释不同的 区域,路由器,和 LSA的区别l解释 OSPF 怎样支持 VLSM?l解释OSPF 区域间的路由汇总的?l配置多区域 OSPF 网络l验证OSPF多区域配置1/27/202341问题问题1.OSPF路由器的路由器的4种类型种类型?2.哪种路由器产生哪种路由器产生 2型型LSA?3.配置一个完全配置一个完全 totally stubby区的优点区的优点?4.在在ABR上上 汇总指定区域路由信息的指令是什么汇总指定区域路由信息的指令是什么?1/27/202342
