R1配置： Router>en
Router#conf t
Router(config)#host R1
R1(config)#int loopback0
R1(config-if)#ip add 1.1.1.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#int s1/2
R1(config-if)#ip add 12.0.0.1 255.255.255.0
Bad mask /24 for address 12.0.0.1
R1(config-if)#ip subnet-zero
R1(config)#int s1/2
R1(config-if)#ip add 12.0.0.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#^Z
R1#
R1#confi t
R1(config)#metric weight 5 4 3 2 1
R1(config)#router rip
R1(config-router)#net 1.0.0.0
R1(config-router)#net 12.0.0.0
R1(config-router)#^Z
R1#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 100 percent (5/5), round-trip min/avg/max = 204/445/896 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 = 296/704/1260 ms R1#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR Gateway of last resort is not set 1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
R 3.0.0.0/8 [120/2] via 12.0.0.2, 00:00:22, Serial1/2
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial1/2
R 23.0.0.0/8 [120/1] via 12.0.0.2, 00:00:22, Serial1/2
R2配置： Router>en
R2(config)#int s2/1
R2(config-if)#ip add 12.0.0.2 255.255.255.0
R2(config-if)#no shut
R2(config)#int s2/3
R2(config-if)#ip add 23.0.0.2 255.255.255.0
R2(config-if)#no shut
R2(config-if)#^Z
R2#conf t
R2(config)#access-list 3 permit 1.0.0.0 R2(config)#router rip
R2(config-router)#net 12.0.0.0
R2(config-router)#net 23.0.0.0
R2(config-router)#offset 3 out 8 s2/3
R2(config-router)#exit
R2(config)#acc
R2(config)#access-list 3 permit 1.1.1.1
R2(config)#^Z
R3配： Router>en
Router#conf t
Router(config)#host R3
R3(config)#int s3/2
R3(config-if)#ip add 23.0.0.3 255.255.255.0
Bad mask /24 for address 23.0.0.3
R3(config-if)#ip subnet-zero
R3(config)#int s3/2
R3(config-if)#ip add 23.0.0.3 255.255.255.0
R3(config-if)#int loopback1
R3(config-if)#ip add 3.3.3.3 255.255.255.0
R3(config)#router rip
R3(config-router)#net 3.0.0.0
R3(config-router)#net 23.0.0.0
R3(config-router)#^Z
R3#ping 1.1.1.1 Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 188/372/720 ms
R3#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR Gateway of last resort is not set R 1.0.0.0/8 [120/5] via 23.0.0.2, 00:00:21, Serial3/2
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback1
R 12.0.0.0/8 [120/4] via 23.0.0.2, 00:00:21, Serial3/2
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, Serial3/2