49CCNA官方PPT课件――RIP

RIP第九章2CisxoEducationSolution动态路由协议•距离向量(distancevector)主要有：RIPIGRP•链路状态(linkstate)有OSPFIS-IS•混合型(hybrid)有EIGRP3CisxoEducationSolution距离矢量的路由协议•定期将路由表复制给相邻的路由器并且进行矢量堆加CDBACBADRoutingTableRoutingTableRoutingTableRoutingTableDistance—HowfarVector—Inwhichdirection4CisxoEducationSolutionDV路由协议的特征•采用周期性的完全更新(发送整个路由表)和触发更新结合的路由更新方式•采用广播的方式进行路由更新（RIPv2采用的是组播）•DV的路由协议有RIPv1，RIPv2，IGRP•EIGRP和BGP属于高级的DV协议，他们学习路径的方式更多的趋近于DV，但是他们具备很多LS的特征（比如触发更新，组播更新等）5CisxoEducationSolution•路由器从收集到的源信息中选择到达目标地址的最佳路径ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0RoutingTable10.2.0.010.3.0.000S0S1RoutingTable10.3.0.0S0010.4.0.0E00RoutingTable10.1.0.010.2.0.0E0S000距离矢量—源信息的获得6CisxoEducationSolution•路由器从收集到的源信息中选择到达目标地址的最佳路径ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0RoutingTable10.1.0.010.2.0.010.3.0.0RoutingTable10.2.0.010.3.0.010.4.0.010.1.0.00011S0S1S1S0RoutingTable10.3.0.0S0010.4.0.0E0010.2.0.0S01E0S0S0100距离矢量—源信息的获得7CisxoEducationSolution距离矢量—源信息的获得•路由器从收集到的源信息中选择到达目标地址的最佳路径ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0RoutingTable10.1.0.010.2.0.010.3.0.010.4.0.0RoutingTable10.2.0.010.3.0.010.4.0.010.1.0.00011S0S1S1S0RoutingTable10.3.0.0S0010.4.0.0E0010.2.0.0S010.1.0.0S012E0S0S0S012008CisxoEducationSolution距离矢量—管理路由信息•路由表的更新过程将通过路由器之间一步一步来完成A更新路由表网络结构的改变将导致路由表的更新9CisxoEducationSolution距离矢量—管理路由信息•路由表的更新过程将通过路由器之间一步一步来完成A更新路由表在下一个周期后路由器A发送更新过的路由表网络结构的改变将导致路由表的更新10CisxoEducationSolution距离矢量—管理路由信息•路由表的更新过程将通过路由器之间一步一步来完成AB更新路由表更新路由表网络结构的改变将导致路由表的更新在下一个周期后路由器A发送更新过的路由表11CisxoEducationSolution收敛时间•收敛时间（convergencetime):从网络拓扑发生变化到网络中所有路由器都知道这个表化的时间就叫收敛时间12CisxoEducationSolution路由回环•每一个节点管理着与之相连的所有网络ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0RoutingTable10.3.0.0S0E0S0S01210.1.0.010.2.0.010.4.0.000RoutingTable10.1.0.0E0S0S0S01210.4.0.010.3.0.010.2.0.000RoutingTable10.2.0.0S0S1S1S01110.1.0.010.4.0.010.3.0.00013CisxoEducationSolution路由回环•缓慢的收敛容易造成路由信息的不一致ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0E0S0S01210.1.0.010.2.0.010.4.0.00DownRoutingTable10.1.0.0E0S0S0S01210.4.0.010.3.0.010.2.0.000RoutingTable10.2.0.0S0S1S1S01110.1.0.010.4.0.010.3.0.00014CisxoEducationSolution路由器C推断到达10.4.0.0网络的最好路径是通过路由器B路由回环ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.002RoutingTable10.1.0.0E0S0S0S01210.4.0.010.3.0.010.2.0.000RoutingTable10.2.0.0S0S1S1S11110.1.0.010.4.0.010.3.0.00015CisxoEducationSolution路由器A根据错误的信息升级它的路由表路由回环ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTableS0S0S0S01210.3.0.010.1.0.010.2.0.010.4.0.002RoutingTableE0S0S0S01410.1.0.010.4.0.010.3.0.010.2.0.000RoutingTableS0S1S1S03110.2.0.010.1.0.010.4.0.010.3.0.00016CisxoEducationSolution无限计数•10.4.0.0网络的跳数将无限大ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.004RoutingTableE0S0S0S01610.1.0.010.4.0.010.3.0.010.2.0.000RoutingTableS0S1S1S05110.2.0.010.1.0.010.4.0.010.3.0.00017CisxoEducationSolution•Packetsfornetwork10.4.0.0bounce(loop)betweenroutersBandC.RoutingLoops（路由环路）18CisxoEducationSolutionDV中解决环路的几种办法•水平分割•毒性逆转•保持失效定时器•触发更新•最大跳数（终极武器）19CisxoEducationSolutionSplitHorizon（水平分割）•不会接收到由自身传达出去的路由信息ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XXXRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.000RoutingTableE0S0S0S01210.1.0.010.4.0.010.3.0.010.2.0.000RoutingTableS0S1S1E11210.2.0.010.1.0.010.4.0.010.3.0.00020CisxoEducationSolutionRoutePoisoning（路由中毒）•路由器将该路由信息的跳数标记为无限大ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.00InfinityRoutingTable10.1.0.0E0S0S0S01210.4.0.010.3.0.010.2.0.000RoutingTable10.2.0.0S0S1S1E11210.1.0.010.4.0.010.3.0.00021CisxoEducationSolutionPoisonReverse（毒性逆转）•反转毒杀可以超越水平分割ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.00InfinityRoutingTable10.1.0.0E0S0S0S01210.4.0.010.3.0.010.2.0.000RoutingTable10.2.0.0S0S1S1E1PossiblyDown210.1.0.010.4.0.010.3.0.000PoisonReverse22CisxoEducationSolutionHolddownTimers（保持失效定时器）•路由器在Hold-Down时间内将该条记录标记为possiblydown以使其它路由器能够重新计算网络结构的变化Network10.4.0.0isdownthenbackupthenbackdownUpdateafterhold-downTimeNetwork10.4.0.0isunreachableABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XUpdateafterhold-downTime23CisxoEducationSolutionTriggeredUpdates（触发更新）•当路由表发生变化时路由器立即发送更新信息ABC10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XNetwork10.4.0.0isunreachableNetwork10.4.0.0isunreachableNetwork10.4.0.0isunreachable10.1.0.024CisxoEducationSolutionMax-Hop（最大跳数）•指定最大跳数来防止路由回环ABC10.1.0.010.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0XRoutingTable10.3.0.0S0S0S0S01210.1.0.010.2.0.010.4.0.0016RoutingTableE0S0S0S011610.1.0.010.4.0.010.3.0.010.2.0.000RoutingTableS0S1S1S016110.2.0.010.1.0.010.4.0.010.3.0.00025CisxoEducationSolutionRIP•在IGP中，RIP是个广泛使用的协议•RIP也称距离矢量协议，用信息包所经过的网关来做距离的单位，超过15跳便无法到达•IGRP是CISCO专用的路由协议，可以服务于大型互连网络，不受限于16跳的限制（默认是100跳）26CisxoEducationSolution19.2kbpsT1T1T1-Hop计算-路由器每隔30秒更新-最多支持相同hop数的6条路径，实现负载均衡RIP概述27CisxoEducationSolutionRIP概述•RIP是通过UDP端口520来进行操作的,RIP信息包是封装在UDPsegment中的.RIP定义了2种信息类型•Requestmessage(请求信息)和Responsemessage(应答