一、实验拓扑：
二、命令部署：
ESW1(config)#int range f0/0 - 2
ESW1(config-if-range)#no shutdown
1、实验要求3部署：
R1(config)#router rip
R1(config-router)#no validate-update-source
R2(config)#router rip
R2(config-router)#no validate-update-source
R3(config)#int f0/0
R3(config-if)#ip add 100.1.1.3 255.255.255.0 secondary
R3(config)#router rip
R3(config-router)#no validate-update-source
2、实验要求4部署：
R3(config)#int f0/0
R3(config-if)#no ip add 100.1.1.3 255.255.255.0 secondary
三、验证：
1、R1、R2、R3之间运行RIP协议后，是否能学习到对方的路由条目？
R1#show ip route rip
2.0.0.0/24 is subnetted, 1 subnets
R 2.2.2.0 [120/1] via 100.1.1.2, 00:00:09, FastEthernet0/0
R2#show ip route rip
1.0.0.0/24 is subnetted, 1 subnets
R 1.1.1.0 [120/1] via 100.1.1.1, 00:00:00, FastEthernet0/0
R3#show ip route rip
结论：R1和R2相互有对方的路由条目，R3没有。
因为R1、R2通过100.1.1.0网段发出更新，R3是通过200.1.1.0网段发出更新。
2、R3部署100.1.1.0的备用地址，查看R1、R2和R3是否能学到对方路由？
R1#show ip route rip
2.0.0.0/24 is subnetted, 1 subnets
R 2.2.2.0 [120/1] via 100.1.1.2, 00:00:25, FastEthernet0/0
R2#show ip route rip
1.0.0.0/24 is subnetted, 1 subnets
R 1.1.1.0 [120/1] via 100.1.1.1, 00:00:12, FastEthernet0/0
R3#show ip route rip
1.0.0.0/24 is subnetted, 1 subnets
R 1.1.1.0 [120/1] via 100.1.1.1, 00:00:20, FastEthernet0/0
2.0.0.0/24 is subnetted, 1 subnets
R 2.2.2.0 [120/1] via 100.1.1.2, 00:00:20, FastEthernet0/0
结论：R3可以学到R1、R2路由条目，R1、R2学不到R3路由；
因为R3部署备用地址，可以接收同网段路由。
3、R1、R2、R3关闭更新源检测，查看R1、R2和R3是否学到对方路由？
R1#show ip route rip
2.0.0.0/24 is subnetted, 1 subnets
R 2.2.2.0 [120/1] via 100.1.1.2, 00:00:02, FastEthernet0/0
3.0.0.0/24 is subnetted, 1 subnets
R 3.3.3.0 [120/1] via 200.1.1.3, 00:00:13
R2#show ip route rip
1.0.0.0/24 is subnetted, 1 subnets
R 1.1.1.0 [120/1] via 100.1.1.1, 00:00:15, FastEthernet0/0
3.0.0.0/24 is subnetted, 1 subnets
R 3.3.3.0 [120/1] via 200.1.1.3, 00:00:02
R3#show ip route rip
1.0.0.0/24 is subnetted, 1 subnets
R 1.1.1.0 [120/1] via 100.1.1.1, 00:06:15, FastEthernet0/0
[120/1] via 100.1.1.1, 00:00:13
2.0.0.0/24 is subnetted, 1 subnets
R 2.2.2.0 [120/1] via 100.1.1.2, 00:06:24, FastEthernet0/0
[120/1] via 100.1.1.2, 00:00:14
结论：R1、R2和R3都可以学到对方的路由条目。
4、R1、R2和R3有对方路由后，是否可以Ping通背后的环回口？
R2#ping 3.3.3.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R3#ping 2.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
