《IP路由高级技术》PPT课件.ppt

2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,1,IP路由协议（三）,NE实验室，2008西安邮电学院,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,2,主要内容,描述OSPF多区域互联和寻址时面临的问题解释不同类型的区域,routers,和LSA之间的区别解释OSPF如何支持VLSM解释OSPF在多区域中如何支持路由汇总能够正确配置一个多区域的OSPF网络,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,3,2000,CiscoSystems,Inc.,5-3,多区域OSPF创建,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,4,维护大型OSPF网络的问题,Myroutingtableistoobig,Iamrunninglowonmemory.,TheSPFisrunningtoooftenformetoroute.,IamonlyreceivingLSAs,nodata.,OSPF,OSPF,OSPF,OSPF,OSPF,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,5,Area0,Area1,Area2,AutonomousSystem,一个自治系统由多个区域组成最小化路由更新产生的业务量,解决方案:OSPF分层路由,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,6,OSPF多区域网络的组成成分,Routers,LSAs,Internal,ABR,ASBR,Backbone,Type1,Type2,Type3/4,Type5,Area0Iamabackbone.,Area2Iamastub.,Area1Iamstandard.,Areas,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,7,ExternalAS,OSPF路由器的类型,InternalRouters,Area1,Area2,BackboneArea0,InternalRouters,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,8,ExternalAS,OSPF路由器的类型,InternalRouters,Area1,Area2,Backbone/InternalRouters,BackboneArea0,InternalRouters,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,9,ExternalAS,OSPF路由器的类型,InternalRouters,Area1,Area2,Backbone/InternalRouters,ABR和BackboneRouter,BackboneArea0,ABR和BackboneRouter,InternalRouters,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,10,ExternalAS,InternalRouters,Backbone/InternalRouters,ABR和BackboneRouter,ABR和BackboneRouter,InternalRouters,ASBR和BackboneRouter,OSPF路由器的类型,Area1,Area2,BackboneArea0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,11,Link-StateAdvertisements的类型,Type1:RouterlinkentryType2:NetworklinkentryType3and4:SummarylinkentryType5:ASexternallinkentry,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,12,OSPF链路状态数据库中的LSA,Router,Area1,Area0,Network,Summary,External,ABR,DR,router#showipospfdatabaseOSPFRouterwithID(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 xE6F8,ASBR,ExternalAS,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,13,区域的类型,骨干区负责互联;它接收所有的LSAs.,BackboneArea0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,14,StubArea,不接受外部LSAs.,区域的类型,骨干区负责互联;它接收所有的LSAs.,BackboneArea0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,15,TotallyStubbyArea,不接受外部路由，也不接收区域间汇总LSAs.,StubArea,不接受外部LSAs.,区域的类型,BackboneArea0,骨干区负责互联;它接收所有的LSAs.,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,16,2000,CiscoSystems,Inc.,5-16,OSPF多区域工作原理,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,17,多区域网络中的分组转发,BBone,Internal,Internal,ABR2,ABR1,Area50,Data,到ABR1,到Backbone,到ABR2,到目的网络,Area1,Area0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,18,洪泛LSUs到多个区域,BBone,Internal,ABR2,ABR1,Internal,Type1,Area1,Area0,Area50Stub,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,19,洪泛LSUs到多个区域,BBone,Internal,ABR2,ABR1,Internal,Type3,Type1,Type3,Area1,Area0,Area50Stub,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,20,Type5,afadjfjorqpoeru39547439070713,Type5,Default,Area1,Area0,BBone,Internal,ABR2,ABR1,Area50Stub,Internal,RIP,Type3,Type3,Type1,洪泛LSUs到多个区域,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,21,洪泛LSUs到多个区域(cont.),RoutingTable,Inter-AreaRoutes,Intra-AreaRoutes,External(Non-OSPFRoutes),Area1,Area1,Area0,Area1,RIP,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,22,2000,CiscoSystems,Inc.,5-22,VirtualLinks简介,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,23,其它区域必须与骨干区直连Virtuallinks提供一条到骨干区的路径应尽可能避免配置Virtuallinks,骨干区域的要求,Area3,Area1,VirtualLink,TransitArea,Area3,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,24,remoterouter#showipospfinterfaceethernet0Ethernet0isup,lineprotocolisupInternetAddress10.64.0.2/24,Area0ProcessID1,RouterID10.64.0.2,NetworkTypeBROADCAST,Cost:10TransmitDelayis1sec,StateDR,Priority1DesignatedRouter(ID)10.64.0.2,Interfaceaddress10.64.0.2BackupDesignatedrouter(ID)10.64.0.1,Interfaceaddress10.64.0.1,配置VirtualLinks,创建virtuallink,Router(config-router)#,areaarea-idvirtual-linkrouter-id,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,25,OSPFVirtualLink配置实例,R2:routerospf63network10.3.0.00.0.0.255area1network10.7.0.00.0.0.255area3area1virtual-link10.3.10.5,R1:routerospf100network10.2.3.00.0.0.255area0network10.3.2.00.0.0.255area1area1virtual-link10.7.20.123,RouterID10.7.20.123,Area3,Area0,Area1,RouterID10.3.10.5,R1,R2,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,26,2000,CiscoSystems,Inc.,5-26,配置实例,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,27,2000,CiscoSystems,Inc.,5-27,多区域OSPF的配置,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,28,OSPFABR配置,E010.64.0.1,10.64.0.2E0,S010.2.1.2,10.2.1.1S1,A,B,C,ABR,interfaceEthernet0ipaddress10.64.0.1255.255.255.0!routerospf77network10.0.0.00.255.255.255area0,Area1,Area0,interfaceEthernet0ipaddress10.64.0.2255.255.255.0!interfaceSerial0ipaddress10.2.1.2255.255.255.0routerospf50network10.2.1.20.0.0.0area1network10.64.0.20.0.0.0area0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,29,Default,Default,Summary,Default,Stub和TotallyStubby区域,Area1TotallyStubby,Area0,Internal,ABR2,ABR1,Area50Stub,Summary,External,External,InternalNon-CiscoRouter,BBone,Summary,RIP,ASBR,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,30,典型的只有一个出口点.内部不允许有ASBR不能是骨干区0不允许Virtuallinks,Stub和TotallyStubby区域的限制,单出口点,Area2,0.0.0.0,R3,R4,ExternalAS,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,31,建立一个stub区域指定发往stub区域缺省路由的cost,Router(config-router)#,areaarea-idstubno-summary,Router(config-router)#,areaarea-iddefault-costcost,配置Stub和TotallyStubby区,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,32,OSPFStub区配置举例,192.168.15.2,Area0,StubArea2,192.168.14.1,192.168.15.1,S0,S0,E0,R3#interfaceEthernet0ipaddress192.168.14.1255.255.255.0interfaceSerial0ipaddress192.168.15.1255.255.255.252routerospf100network192.168.14.00.0.0.255area0network192.168.15.00.0.0.255area2area2stub,R4#interfaceSerial0ipaddress192.168.15.2255.255.255.252routerospf15network192.168.15.00.0.0.255area2area2stub,ExternalAS,R4,R3,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,33,R4#routerospf15network192.168.15.00.0.0.255area2area2stub,OSPFTotallyStubby区配置,R3#routerospf100network192.168.14.00.0.0.255area0network192.168.15.00.0.0.255area2area2stubno-summary,192.168.15.2,Area0,192.168.14.1,192.168.15.1,S0,S0,E0,ExternalAS,R4,R3,TotallyStubbyArea2,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,34,减小路由表的条目限制拓扑改变的影响范围减少LSA的数目,支持路由汇总,Area0Backbone,ABRs,Area1,汇总,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,35,支持VLSM,OSPF携带subnet掩码信息使用分层地址结构,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,36,区域间(IA)链路汇总消息携带掩码信息一项代表多个子网subnets,使用路由汇总,O172.16.8.0255.255.252.0O172.16.12.0255.255.252.0O172.16.16.0255.255.252.0O172.16.20.0255.255.252.0O172.16.24.0255.255.252.0O172.16.28.0255.255.252.0,B的RoutingTable,发往路由器C的LSAs,IA172.16.16.0255.255.240.0,Area1,Area0,ABR,汇总,B,A,C,IA172.16.8.0255.255.248.0,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,37,在ABR上合并内部路由在ASBR合并外部路由,Router(config-router)#,areaarea-idrangeaddressmask,Router(config-router)#,summary-addressaddressmasknot-advertisetagtag,配置路由汇总,2019/11/19,YangWu-Jun,xianInstituteofPostandTelecommuniations,38,路由汇总配置举例,R2,R2#routerospf100network172.16.64.10.0.0.0area2network172.16.127.10.0.0.0area0area0range172.16.96.0255.255.224.0area2range172.16.64.0255.255.224.0,172.16.64.0-172.16.95.0255.255.25