R1的配置：
1 2 3 4 5 6 7 | ! interface FastEthernet0/0 ip address 192.168.1.1 255.255.255.0 duplex auto speed auto ! ip route 172.16.1.0 255.255.255.0 192.168.1.2 |
R2的配置：
1 2 3 4 5 6 7 8 9 10 | ! interface FastEthernet0/0 ip address 192.168.1.2 255.255.255.0 duplex auto speed auto ! interface FastEthernet0/1 ip address 172.16.1.2 255.255.255.0 duplex auto speed auto |
R3的配置：
1 2 3 4 5 6 7 | ! interface FastEthernet0/1 ip address 172.16.1.1 255.255.255.0 duplex auto speed auto ! ip route 192.168.1.0 255.255.255.0 172.16.1.2 |
