RIP协议的基本配置（2）
配置清单5-2 配置RIP协议
第1段：配置RIP协议
R1#conft
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1(config-router)#eetwork 172.16.0.0
R1(config-router)#
Term_Server>2
[Resuming connection 2 to R2 ...]
R2#conft
Enter configuration commands, one per line. End with CNTT ./Z
R2(config)#router rip
R2(config-router)#network 172.16.0.0
R2(config-router)#
Term_Server>3
[Resuming connection 3 to R3 ...]
R3#conft
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router rip
R3(config-router)#network 172.16.0.0
R3(config-router)#
第2段：查看路由表
Term_Server> 1
[Resuming connection I to R1... ]
R1(config-router)#end
R1#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, 0 - OSPF, IA - OSPF inter area
N - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 6 subnets
R 172.16.23.0[20/1]via 172.16.12.2,00:00:06,Serial0
[20/1]via 172.16.13.3,00:00:07,Serial1
C 172.16.12.0 is directly connected, Serial0
C 172.16.13.0 is directly connected. Serial1
C 172.16.1.0 is directly connected, Ethernet0
R 172.16.2.0[20/1]via 172.16.12.2,00:00:06,Serial0
R 172.16.3.0[20/1]via 172.16.13.3,00:00:07,Serial1
R1#
Term_Server>2
[Resuming connection 2 to R2 ... ]
R2(config-router)#end
R2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M " mobile, B - BGP
D - EIGRP, EX - EIGRP external, 0 - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type I, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 6 subnets
C 172.16.23.0 is directly connected, Seriall
C 172.16.12.0 is directly connected, SerialO
R 172.16.13.0[20/1]via 172.16.12.1,00:00:08,Serial0
[20/1]via 172.16.23.3,00:00:09,Serial1
R 172.16.1.0[20/1]via 172.16.12.1,00:00:08,Serial0
C 172.16.2.0 is directly connected, Ethernet0
R 172.16.3.0[20/1]via 172.16.23.3,00:00:09,Serial1
R2#
Term_Server>3
[Resuming connection 3 to R3 ... ]
R3(config-.router)#end
R3#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX -EIGRP external, 0 - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 6 subnets
C 172.16.23.0 is directly connected, Serial1
R 172.16.12.0 [120/13 via 172.16.13.1, 00:00:17, Serial0
[120/1} via 172.16.23.2, 00:00:26, Serial1
C 172.16.13.0 is directly connected, SerialO
R 172.16.1.0 [120/1] via 172.16.13.1, 00:00:17, Serial0
R 172.16.2,0 [120/1] via 172.16.23.2,00:00:26, Serial1
C 172.16.3.0 is directly connected, Ethemet0
R3#
(1)RIP协议的基本配置非常简单。首先使用router ip命令进入RIP协议配置模式，然后用network语句声明进入RIP进程的网络。
可以看到netwo比语句中使用的是网络号，而不是子网号。当我们试图把172.16.1.0这一子网号码加入R1的RIP路由进程中而发出network l72.16.0.0的命令后，show running-config的结果会显示此处的语句变成为network 172.16.0.0，即B类网络172.16.0.0下的所有子网都加入了RIP路由进程。
(2)使用show ip route命令查看路由表。在R1路由器上可以看到，通过RIP协议，学马到了与R1不直接相连的网段172.16.23.0、172.16.2.0和17216.3.0。路由表中的项目解释如下。
R 172.16.2.0[120/1]via 172.16.12.2,00:00:06,Serial0
R: 表示此项路由是由RIP协议获取的，另外，"C，代表直连的网段。
172.16.2.0: 目标网络。
[120/1]: 12O是RIP协议的治理距离，1是该条路由的度量值，即Metric值，即跳数。
via: 经由的意思。
172.16.12.2:是由当前路由器出发，到达目标网段所需经过的下一个跳点的IP地址。
00:00:06: 此条路由产生的时间，即65钟。
Serial0: 由此路由器到达目标网段所需使用的接口。
(3)从3台路由器的路由表中可以看出RIP协议工作正常，所有网段的路由条目都已具备。
(4)对于路由器R1的路由表而言。172.16.23.0这条路由项具有2个路径，即表中列出的172.26.12.2和172.16.13.3，表示到达172.16.23.0网段可以通过R2路由器，也可以通过R3路由器，表明有两条等值的路径存在，其度量值均为1。
路由器R2和R3都有类似的路由存在。
(5)从实验拓扑图可以分析出，从R2发送到R3的数据包假如经由R1的话会有较高的带宽(5OOkbit/s)，是应该首选的路由。但路由表中显示的实际情况是选择了由R2直接发送到R3。这表明RIP路由协议在进行路由计算时只考虑两个网段之间的跳数这个惟一的度量值，而不考虑诸如带宽。延迟等其他因素。
监测清单5-1记录了RIP协议常用的监测命令的使用。
监测清单5-1 RIP协议常用监测命令
R3#sh ip protocol
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 24 second
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Triggered TIP Key-chain
Ethernet0 1 12
Serial0 1 12
Serial1 1 12
Autonaatic network sunamarization is in effect
Routing for Networks:
172.16.0.0
Routing Information Sources:
Gateway Distance Last Update
172.16.23.2 120 00:00:14
172.16.13.1 120 00:00:00
Distance: (default is 120)
R3#pmg 172.16.1.1
Type escape sequence to abort.
Sending 5, 100-bytelCMPEchos to 172.16.1.1,timeout is 2 seconds:
!!!!!
SUCcess rate is 100 percent (5/5), rouad-tripmin/avg/max=8/8/8 ms
R3#trace 172.16.1.1
Type escape sequence to abort.
Tracing the route to 172.16.1.1
1 172.16.13.14 msec *
R3#conft
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#int s1
R3(config-if)#shut
R3(config-if)#end
R3#sh ip route
Codes: C - connecte-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 5 subnets
R 172.16.12.0 [120/1] via 172.16.13.1, 00:00:04, Serial0
C 172.16.13.0 is directly connected, Serial0
R 172.16.1.0 [120/1] via 172.16.13.1, 00:00:04, Serial0
R 172.16.2.0 (.120/21 via 17246.13.1, 00:00:04,Serial0
C 172.16.3.01s directly connected, Ethernet0
R3#trace 172.16.2.2
Type escape sequence to abort.
Tracing the route to 172.16.2.2
1 172.16.13.14 msec 4 msec 8 msec
2 172.16.12.2 16 msec 8 msec*
R3#conft
Enter configuration commands,one per line.End with CNTL/Z.
R3(config)#int s1
R3(ocnfig-if)#no sh
R3(config-if)#exit
R3(config)#logg con
R3(config)#exit
R3#de
01:29:45:%SYS-5CONFIG_I:Configured from console by console
R3:debug ip rip
RIP protocol debugging is on
R3#
01:29:56:RIP:sending v1 update to 255.255.255.255 via Ethernet0(172.16.3.3)
01:29:56:RIP:build update entries
01:29:56: subnet 172.16.1.0 metric 2
01:29:56: subnet 172.16.2.0 metric 2
01:29:56: subnet 172.16.12.0 metric 2
01:29:56: subnet 172.16.13.0 metric 1
01:29:56: subnet 172.16.23.0 metric 1
01:29:56: RIP: sending v1 update to 255.255.255.255 via Serial0 (172.16.13.3)
01:29:56: RIP: build update entries
01:29:56: subnet 172.16.2.0 metric 2
01:29:56: subnet 172.16.3.0 metric 1
01:29:56: subnet 172.16.23.0 metric 1
01:29:56: RIP: sending v1 update to 255.255.255.255 via Serial1 (172.16.23.3)
01:29:56: RIP: build update entries
01:29:56: subnet 172.16.1.0 metric 2
01:29:56: subnet 172.16.3.0 metric 1
01:29:56: subnet 172.16.13.0 metric 1
01:30:00: RIP: received v1 update from 172.16.23.2 on Serial1
01:30:00: 172.16.1.0 in 2 hops
01:30:00: 172.16.2.0 in 1 hops
01:30:00: 172.16.12.0 in 1 hops
R3#
01:30:07: RIP: received v1 update from 172.16.13.1 on Serial0
01:30:07: 172.16.1.0 in 1 hops
01:30:07: 172.16.2.0 in 2 hops
01:30:07: 172.16.12.0 in 1 hops
R3-#indebug all
(1)show ip protocol命令的执行结果中包含了有关RIP协议的大量信息，主要有:各种计时器信息;
版本信息，发送version 1，接收任何version;
各接口的发送(Send)和接收(Receive)的版本;
自动汇总生效(Automatic network summarization is in effect);
所路由的网络，172.16.0.0;
路由信息源，即从何处学月来的路由;
治理距离，缺省值为120。
(2)用ping和trace命令测试网络连通性，尤其是trace命令给出了相应的路径信息。
(3)我们把R3路由器的S1接口关闭后，使用show ip route指令查看路由表，显示到达172.16.2.0的路由己经变为R1，度量值也变为2.
trace命令的结果也显示了这一变化。
(4)使用debug ip rip命令可以监测到RIP协议的路由更新发送和接收情况，在此命令后面的若干行中，可以看出RIP协议工作的特点，大致有以下几点:
更新信息缺省情况下向所有参与路由的接口发送;
RIP版木1的更新包是广播包，即目的地址为255.255.255.255;
RIP把整个路由表向相邻路由器发送;
当前所有接口发送和接收的RIP更新包的版本均为1。
(5)最后应关闭debug进程。
