监测清单5-2使用RIP协议处理VLSM和配置被动接口
第1段：RIPv1配置下的路由表
R3#sh ip route rip
172.16.0.0/30 is subnetted, 3 subnets
R172.16.123.0 [120/1] via l72.16.123.5,00:00:12,Serial0
[120/1] via l72.16.123.9,00:00:12,Serial1
第2段：配置RIPv2和no summary
R3#conft
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router rip
R3(config-router)#ver 2
R3 (config-router)#no auto-summary
Term_Server2
[Resuming connection 2 to R2 ... ]
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router rip
R2(config-router)#ver 2
R2(config-router)#no auto-summary
Term_Server 1
[Resuming connection 1 to R1 ... ]
R1#conft
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1(config-router)#ver 2
R1 (config-router)#no auto-summary
R1(config-rotuer)#end
R1#
R1#sh ip prot
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 5 seconds
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 2, receive version 2
InterfaceSendRecvTriigered RIPKey-chain
Ethemet0 22
Serial022
Serial122
Automatic network summarization is not in effect
Routing for Networks:
172.16.0.0
172.18.0.0
Routing Information Sources:
GatewayDistanceLast Update
172.16.123.612000:00:06
172.16.123.212000:00:04
Distance: (default is 120)
R1#sh ip route rip
172.16.0.0/30 is subnetted, 3 subnets
R172.16.123.8 [120/1] via 172.16.123.2, 00:00:06, Serial0
[120/1] via 172.16.123.6, 00:00:22, Serial1
172.18.0.0/16 is variably subnetted, 3 subnets, 2 masks
R172.18,2,0/28 [120/1] via 172.16.123.2,00:00:06,SerialO
R172.18J.O/24 [120/1] via 172.16.123.6, 00:00:22, Serial1
第3段：配置 passive interface
R1#debug ip rip
RIP protocol debugging is on
R1#
02:59:47: RIP: received v2 update from 172.16.123.6 on Serial1
02:59:47:172.16.123.8/30 via 0.0.0.0 in 1 hops
02:59:47:172.18.2.0/28 via 0.0.0.0 in 1 hops
02:59:47:172.18.3.0/24 via 0.0.0.0 in 1 hops
R1#
02:59:51: RIP: sending v2 update to 224.0.0.9 via Ethernet 0(172.18.1.1)
02:59:51: RIP: build update entries
02:59:51: 172.16.123.0/30 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.16.123.4/30 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.16.123.8/30 via 0.0.0,0, metric 2, tag 0
02:59:51: 172.18.2.0/28 via 0.0.0.0, metric 2,tab 0
02:59:51: 172.183.0/24 via0.0.0.0,metric 2,tag 0
02:59:51: RIP: sendiag v2 update to 224.0.:0.9viaSaialC-172.15.t23.1)
02:59:51: RIP: build update entries
02:59:51: 172.16.123.4/30 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.18.1.0/28 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.18.3.0/24 via 0.0.0.0, metric 2, tag 0
R1#
02:59:51: RIP: sending v2 update to 224.0.0.9 via Serial1(172.16.123.5)
02:59:51: RIP: build update entries
02:59:51: 172.16.123.0/30 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.18.1.0/28 via 0.0.0.0, metric 1, tag 0
02:59:51: 172.18.2.0/28 via 0.0.0.0, metric 2, tag 0
R1#u all
All possible debugging has been turned off
R1#conft
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1(config-router)passive-interface ?
Ethernet IEEE 802.3
NullNull interface
SerialSerial
defaultSuppres s routing updates. on all interfaces
R1 (config-router)passive-interface e0
R1(config-router)#passive-interface s0
R1(config-router#^Z
R1#debugiprip
RIP protocol debugging is on
R1#
03:00:54: RIP: received v2 update from 172.16.123.2 on Serial0
03:00:54:172.16.123.8/30 via 0.0.0.0 in 1 hops
03:00:54:172.18.2.0/28 via 0.0.0.0 in 1 hops
03:00:54:172.18.3.0/24 via 0.0.0.0 in 2 hops
R1#
3:00:56:RIP:sending v2 flash update to 224.0.0.9 via Serial1(172.16.123.5)
03:00:56: RIP: build flash update entries
03:00:56: 172.18.2.0/28 via 0.0.0.0, metric 2, tag 0
R1#
03:01:12:RIP:received v2 update from 172.16.123.6 on Serial1
03:01:12: 172.16.123.8/30 via0.0.0.0 in 1 hops
03:01:12: 172.18.2.0/28 via 0.0.0.0 in 2 hops
03:01:12: 172.18.3.0/24 via 0.0.0.0 in 1 hops
R1#
03:01:17:RIP:sending v2 flash update to 224.0.0.9 via Serial1(172.16.123.5)
03:01:17: RIP: build update entries
03:01:17: 172.16.123.0/30 via 0.0.0.0, metric 1, tag 0
03:01:17: 172.18.1.0/28 via 0.0.0.0,. metric 1,tag 0
03:01:17: 172.18.2.0/28 via 0.0.0.0, metric 2, tag 0
R1#
03:01:23:RIP:received v2 update from 172.16.123.2 on Serial1
03:01:23:172.16.123.8/30 via 0.0.0.0 in 1 hops
03:01:23:172.18.2.0/28 via 0.0.0.0 in 1 hops
03:01:23:172.18.3.0/24 via 0.0.0.0 in 2 hops
R1#conft
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1 (config-router)#passive-mterface default
R1(config-router#^Z
R1#
Term_Server2
[Resuming connection 2 to R2 ... ]
R2#cle ip route *
R2#
Term_Server3
[Resuming connection 3 to R3 ... ]
R3#cle ip route *
R3#
Term_Server1
[Resuming connection 1 to R1... ]
R1#sh ip route rip
172.16.0.0/30 is subnetted,3 subnets
R172.16.123.8[120/1]via 172.16.123.2,00:00:09,Serial1
[120/1]via 172.16.123.6,00:00:17,Serial0
172.18.0.0/16 is variably subnetted,3 subnets,2 masks
R172.18.2.0/28[120/1] via 172.16.123.2,00:00:17,Serial0
R172.18.3.0/24[120/1] via 172.16.123.6,00:00:09,Serial1
R1#
Term_Server2
[Resuming connection 2 to R2...]
R2#
R2#sh ip route rip
172.16.0.0/30 is subnetted,3 subnets
R172.16.123.4[120/1]via 172.16.123.10,00:00:24,Serial1
172.18.0.0/16 is variably subnetted,2 subnets,2 masks
R172.18.3.0/24[120/1] via 172.16.123.10,00:00:24,Serial1
R2#
Term_Server3
[Resuming connection 3 to R3...]
R3#sh ip route rip
172.16.0.0/30 is subnetted,3 subnets
R172.16.123.0120/1] via 172.16.123.9,00:00:26,Serial1
172.18.0.0/16 is variably subnetted,2 subnets,2 masks
R172.18.2.0/28[120/1] via 172.16.123.9,00:00:26,Serial1
(1)在缺省情况下，RIP的版本是1。第1段中，在RIPv1配置下，R3路由器show ip routerip命令的结果只能看到1条172.16.123.0的路由。
(2)第2段中，分别把3台路由器设为RIPv2，并且关闭路由自动汇总，所使用的命令况version2和no auto-summary，均在router rip模式下发出。
(3)show ip protocol命令显示了更改配置之后RIP协议的配置信息，引人注目的是发送和接收的版本均变为2，以及自动网络汇总不生效。
(4)show ip route rip命令显示出了我们希望看到的结果，即172.18.2.0/28和172.18.3.0/24网段出现在路由表中，表明RIPv2可以解决VLSM问题，使IP地址分配可以灵活高效地进行。
在其他路由器上查看路由表会得到类似的结果。
(5)第3段中，首先通过debug ip rip命令监测RIPv2的工作特性。可以看到RIPv2向各个接口(R1的E0、S0和S1接口)发送更新包，使用的是组播地址224.0.0.9。
(6)使用passive-interface e0和passive-interface s0命令可以把E0和S0接口设置成为被动接口。被动接口只接收路由更新包，而不向外发送路由更新包。
(7)debug ip rip命令的执行结果显示了配置完被动接口后RIP包的传送情况，可以看到只有引接口还有路由更新包的发送。
(8)使用passive-interface default命令可以把所有接口均设置为被动接口。
为了查看这个命令的作用，我们在每台路由器上首先清除路由表，强迫路由表的更新。然后查看每台路由器的路由表申由RIP得来的路由。
R1的路由表显示了与它不直接相连的所有3个网段。
R2和R3的路由表没有显示R1的E0网段，即172.18.1.0/28，这是因为R1路由器没有向外发布任何RIP信息。
