动态路由选择原理距离矢量协议rip

课程目标动态路由协议概述RIPRIP基础实验动态路由协议概述••路由动态路由协议动态路由协议的分类路由192.168.10.0/24172.16.1.0/24ProtocolDestinationNetworkExit

InterfaceConnected192.168.10.0e0RIP172.16.1.0s0s0e0路由当路由器（或其他三层设备）收到一个IP数据包时，会查看数据包的IP头部中的目的IP地址，并在路由表中进行查找，在匹配到最优的路由后，将数据包扔给该路由所指的出接口或下一跳。动态路由协议学会查看路由表R1#

show

ip

routeGateway

of

last

resort

is

not

set2.0.0.0/24

is

subnetted,

1

subnetsO 2.2.2.0

[110/65]

via

9.9.12.2,

00:00:02,

Serial0/09.0.0.0/24

is

subnetted,

1

subnetsC 9.9.12.0

is

directly

connected,

Serial0/0动态路由协议路由协议的分类静态路由由管理员根据数据 需求手工在每台设备上进行添加和动态路由协议路由器自动进行路由信息的更新和同步，并且当网络拓扑变更时，能够自动收敛R1#

show

ip

route2.0.0.0/24

is

subnetted,

1

subnetsO 2.2.2.0

[110/65]

via

9.9.12.2,

00:00:02,

Serial0/09.0.0.0/24

is

subnetted,

1subnetsC 9.9.12.0

is

directly

connected,

Serial0/0动态路由协议动态路由协议的分类动态路由协议网关协议IGP外部网关协议EGP距离矢量协议链路状态协议RIPEIGRPOSPFIS-ISBGPRIP距离矢量路由协议概述RIP概述RIP路由更新过程路由环路的产生及避免RIP基本配置距离矢量路由选择协议使用距离矢量路由协议的路由器并不了解网络的拓扑。该路由器只知道：自身与目的网络之间的距离应该往哪个方向或使用哪个接口转发数据包R1R2S0S1E0到2.2.2.0/24通过R2可以到达（方向）需经过一跳（距离）路由：我这有个2.2.2.02.2.2.0/24距离矢量路由选择协议DAC距离矢量的特点：–

周期性地更新（广播）整张路由表Distance—How

farVector—In

which

directionBABCDRoutingTableRoutingTableRoutingTableRoutingTable距离矢量路由选择协议路由器初始启动–

最初的网络发现：直连网络写入路由表B10.1.0.0CA10.3.0.010.4.0.0E010.2.0.0S0

S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S00Routing

Table10.2.0.0S0010.3.0.0S10Routing

Table10.3.0.0S0010.4.0.0E00距离矢量路由选择协议初次路由信息交换B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S01Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0E0010.2.0.0S01Routing

InformationRouting

Information距离矢量路由选择协议路由收敛完成B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0E0010.2.0.0S0110.1.0.0S02Routing

InformationRouting

Information距离矢量路由选择协议路由器收敛完成当所有路由表包含相同网络可达性信息网络（路由）进入一个稳态路由器继续交换路由信息当无新路由信息被更新时收敛结束网络在达到收敛前无法完全正常工作metric

路由度量值RIP以跳数（Hops）作为metricBDCAE56K1G1G1G2

跳56Kmetric

路由度量值RIP度量值的查看R1#

show

ip

routeC

192.168.12.0/24

is

directly

connected,

Serial0/0R

192.168.23.0/24

[120/1]

via

192.168.12.2,

00:00:08,

Serial0/0Metric=1跳S0/0192.168.12.1/24R2S0/0192.168.12.2/24S0/1192.168.23.2/24S0/0192.168.23.3/24R3R1Administrative

Distance管理距离（AD值）R1R3R2Administrative

Distance管理距离（AD值）Routing

ProtocolsAD备注直连接口0关联出接口的静态路由1Metric

=0关联下一跳的静态路由1Metric

=0EIGRP汇总路由5外部BGP20EIGRP90IGRP100OSPF110RIPv1、v2120外部EIGRP170BGP200距离矢量路由选择协议依照传闻的更新（广播、更新路由表）–

逐跳更新AB拓扑变化触发路由更新更新本地路由表发送更新后的路由信息更新本地路由表环路的产生B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0E0DOWN10.2.0.0S0110.1.0.0S02环路的产生(cont.)B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0210.2.0.0S0110.1.0.0S02update环路的产生(cont.)B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S04Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1310.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0210.2.0.0S0110.1.0.0S02updateupdate环路的产生(cont.)B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S06Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1510.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0410.2.0.0S0110.1.0.0S02updateupdate距离矢量路由选择协议的防环机制有多种机制可以消除路由环路。这些机制包括：定义最大度量以防止计数至无穷大水平分割路由毒性逆转抑制计时器触发更新环路避免定义最大跳数（16跳为不可达）B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S016Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S11610.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S01610.2.0.0S0110.1.0.0S02updateupdate环路避免水平分割Split

HorizonB10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0010.2.0.0S0110.1.0.0S02updateupdate环路避免路由RoutePoisoning10.4.0.0

inaccessible

16跳B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1110.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0Infinity10.2.0.0S0110.1.0.0S02环路避免毒性反转Poison

ReverseB10.1.0.0CA10.2.0.010.4.0.0E0S0S0E0Routing

Table10.1.0.0E0010.2.0.0S0010.3.0.0S0110.4.0.0S02Routing

Table10.2.0.0S0010.3.0.0S1010.4.0.0S1PossiblyDown10.1.0.0S01Routing

Table10.3.0.0S0010.4.0.0S0Infinity10.2.0.0S0110.1.0.0S02PoisonReverse10.3.0.0S1

S0环路避免抑制计时器Hold-Down

Timers为正在重新收敛的网络增加了应变能力引入了某种程度的怀疑量B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E010.4.0.0

DOWNUpdate

afterhold-down

TimeUpdate

afterhold-down

Time环路避免触发更新Triggered

Updates–

拓扑发生变更时，路由器立即发送更新消息，而不等更新计时器超时B10.1.0.0CA10.2.0.010.3.0.010.4.0.0E0S0S0S1S0E010.4.0.0

DOWN10.4.0.0

DOWNRIP协议概述RIP（Routing

Information

Protocols，路由信息协议），是应用较早、使用较普遍的 网关协议(Interi ateway

Protocol,简称IGP)，适用于小型网络，是典型的距离矢量协议。RIP是基于UDP，端口520的应用层协议。管理性距离：120RIP

versionVersion1Version2RIPngRIPv2在v1的基础上增加了外部路由标记VLSM支持组播能力224.0.0.9认证下一跳RIP的配置配置RIPRouter(config)#router

ripRouter(config-router)#network

network-number启动RIP路由选择进程指定的直连网络（接口）RIP只支持主类网络Router(config-router)#version

1/2指定RIP的版本RIP基础实验RIP的配置router

ripversion

2network

1.0.0.0network

192.168.12.0R21.1.1.1/24R3R13.3.3.3/24E0192.168.12.0/24S0S0192.168.23.0/24S1S0E0router

ripversion

2network

192.168.12.0network

192.168.23.0router

ripversion

2network

192.168.23.0network

3.0.0.0RIP的自动汇总172.16.1.0/241