CCIE职业发展系列典型案列分析之配置单播更新（Unicast Update）

案例：

说明： 192.168.10.1/24 

            192.168.20.1/24

           192.168.30.1/24用loopback模拟的.

默认的RIPv1使用广播更新的，现在要把RT1  和 RT3 之间不能交换路由信息，但RT1 和 RT2 ，RT2 和 RT3 可以交换信息。

路由表信息：

RT1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - 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
       i - IS-IS, su - IS-IS summary, 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

R    192.168.30.0/24 [120/1] via 192.168.1.3, 00:00:14, FastEthernet0/0
C    192.168.10.0/24 is directly connected, Loopback0
R    192.168.20.0/24 [120/1] via 192.168.1.2, 00:00:27, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/0

可以看到此时RT1与RT3 交换了路由信息。

报文的通告方式：

RT1#debug ip rip
RIP protocol debugging is on
RT1#
*Mar  1 00:07:46.587: RIP: received v1 update from 192.168.1.3 on FastEthernet0/0
*Mar  1 00:07:46.587:      192.168.30.0 in 1 hops
*Mar  1 00:07:49.427: RIP: sending v1 update to 255.255.255.255 via FastEthernet0/0 (192.168.1.1)
*Mar  1 00:07:49.431: RIP: build update entries
*Mar  1 00:07:49.431:   network 192.168.10.0 metric 1

可以看到 还是广播的更新。

解决方案：

RT1(config)#router rip
RT1(config-router)#passive-interface fastEthernet 0/0
RT1(config-router)#neighbor 192.168.1.2

RT3(config)#router rip
RT3(config-router)#passive-interface fastEthernet 0/0
RT3(config-router)#neighbor 192.168.1.2

配置完成后的结果

路由表信息：

RT1#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - 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
       i - IS-IS, su - IS-IS summary, 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

C    192.168.10.0/24 is directly connected, Loopback0
R    192.168.20.0/24 [120/1] via 192.168.1.2, 00:00:20, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/0

此时 RT1已经学不到RT3上面的路由了。

报文的通告方式：

RT1#debug ip rip
*Mar  1 00:13:31.547: RIP: sending v1 update to 192.168.1.2 via FastEthernet0/0 (192.168.1.1)
*Mar  1 00:13:31.551: RIP: build update entries
*Mar  1 00:13:31.551:   network 192.168.10.0 metric 1
*Mar  1 00:13:36.175: RIP: sending v1 update to 255.255.255.255 via Loopback0 (192.168.10.1)
*Mar  1 00:13:36.179: RIP: build update entries
*Mar  1 00:13:36.179:   network 192.168.1.0 metric 1
*Mar  1 00:13:36.183:   network 192.168.20.0 metric 2
*Mar  1 00:13:37.555: RIP: received v1 update from 192.168.1.2 on FastEthernet0/0
*Mar  1 00:13:37.555:      192.168.20.0 in 1 hops

此时看到 通告方式已经有广播变成了 单播.

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