R1的配置：
R1(config)#router rip
R1(config-router)#ver 2
R1(config-router)#net 12.0.0.0
R1(config-router)#net 172.16.0.0
R1(config-router)#no auto-summary
R1的路由表：
R1#sho 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
23.0.0.0/24 is subnetted, 1 subnets
R 23.0.0.0 [120/1] via 12.0.0.2, 00:00:01, Serial1/0
172.16.0.0/24 is subnetted, 2 subnets
C 172.16.1.0 is directly connected, Loopback0
R 172.16.2.0 [120/2] via 12.0.0.2, 00:00:01, Serial1/0
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial1/0
R1#ping 172.16.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/54/68 ms
R1#ping 23.0.0.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 23.0.0.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 60/72/88 ms
R2的配置：
R2(config)#router rip
R2(config-router)#ver 2
R2(config-router)#net 12.0.0.0
R2(config-router)#net 23.0.0.0
R2(config-router)#no auto-summary
R2的路由表：
R2#sho 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
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, Serial1/0
172.16.0.0/24 is subnetted, 2 subnets
R 172.16.1.0 [120/1] via 12.0.0.1, 00:00:07, Serial1/2
R 172.16.2.0 [120/1] via 23.0.0.3, 00:00:23, Serial1/0
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial1/2
R2#ping 172.16.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/60/128 ms
R2#ping 172.16.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/44/76 ms
R3的配置：
R3(config)#router rip
R3(config-router)#ver 2
R3(config-router)#net 23.0.0.0
R3(config-router)#net 172.16.0.0
R3(config-router)#no auto-summary
R3的路由表：
R3#sho 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
