R3配置
R3>enable
R3#configure terminal
R3(config)#interface loopback 0
R3(config-if)#ip address 10.0.4.1 255.255.255.0
R3(config)#exit
R3(config)#interface f0/0
R3(config-if)#ip address 192.168.0.2 255.255.255.252 #图为30段掩码，所以是252
R1配置
R1(config)#interface f0/0
R1(config-if)#ip address 192.168.0.1 255.255.255.252
R1(config)#exit
R1(config)#interface f0/1
R1(config-if)#ip address 192.168.0.5 255.255.255.252
R1(config)#exit
R1(config)#ip route 10.0.4.0 255.255.252.0 192.168.0.6
R1(config)#ip route 10.0.4.0 255.255.255.0 192.168.0.2
R2配置
R3(config)#interface loopback 0
R3(config-if)#ip address 10.0.5.1 255.255.255.0
R3(config)#interface loopback 0
R3(config-if)#ip address 10.0.7.1 255.255.255.0
R3(config)#exit
R3(config)#interface f0/0
R3(config-if)#ip address 192.168.0.6 255.255.255.252
