设置虚拟链路

R1和R4的互联地址为10.0.0.0/30，R1和R2的互联地址为10.0.0.4/30，R2和R3的互联地址为10.0.0.8/30.用各路由器的Loopback0地址作为Router ID，并配置Loopback1接口地址来模拟网络环境
R1：Lo0：1.1.1.1/32， Lo1：192.168.0.1/24
R2：Lo0：2.2.2.2/32， Lo1：192.168.1.1/24
R3：Lo0：3.3.3.3/32， Lo1：192.168.2.1/24
R4：Lo0：4.4.4.4/32， Lo1：192.168.3.1/24

R1(config)#interface fastEthernet 0/0
R1(config-if)#ip address 10.0.0.1 255.255.255.252
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface fastEthernet 1/0
R1(config-if)#ip address 10.0.0.5 255.255.255.252
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface loopback 0
R1(config-if)#ip address 1.1.1.1 255.255.255.255
R1(config-if)#exit
R1(config)#interface loopback 1
R1(config-if)#ip address 192.168.0.1 255.255.255.0
R1(config-if)#exit

R2(config)#interface fastEthernet 1/0
R2(config-if)#ip address 10.0.0.6 255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 10.0.0.9 255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface loopback 0
R2(config-if)#ip address 2.2.2.2 255.255.255.255
R2(config-if)#exit
R2(config)#interface loopback 1
R2(config-if)#ip address 192.168.1.1 255.255.255.0  
R2(config-if)#exit

R3(config)#interface fastEthernet 0/0
R3(config-if)#ip address 10.0.0.10 255.255.255.252
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface loopback 0
R3(config-if)#ip address 3.3.3.3 255.255.255.255
R3(config-if)#exit
R3(config)#interface loopback 1
R3(config-if)#ip address 192.168.2.1 255.255.255.0
R3(config-if)#exit

R4(config)#interface fastEthernet 0/0
R4(config-if)#ip address 10.0.0.2 255.255.255.252
R4(config-if)#no shutdown
R4(config-if)#exit
R4(config)#interface loopback 0
R4(config-if)#ip address 4.4.4.4 255.255.255.255
R4(config-if)#exit
R4(config)#interface loopback 1
R4(config-if)#ip address 192.168.3.1 255.255.255.0
R4(config-if)#exit

R3(config)#router ospf 10
R3(config-router)#router-id 3.3.3.3
R3(config-router)#network 3.0.0.0 0.255.255.255 area 2   
R3(config-router)#network 10.0.0.8 0.0.0.3 area 2
R3(config-router)#network 192.168.2.0 0.0.0.255 area 2

R2(config)#router ospf 10
R2(config-router)#router-id 2.2.2.2
R2(config-router)#network 2.0.0.0 0.255.255.255 area 2
R2(config-router)#network 10.0.0.8 0.0.0.3 area 2
R2(config-router)#network 10.0.0.4 0.0.0.3 area 1
R2(config-router)#network 192.168.1.0 0.0.0.255 area 1

R1(config)#router ospf 10
R1(config-router)#router-id 1.1.1.1
R1(config-router)#network 1.0.0.0 0.255.255.255 area 1
R1(config-router)#network 10.0.0.4 0.0.0.3 area 1
R1(config-router)#network 192.168.0.0 0.0.0.255 area 1
R1(config-router)#network 10.0.0.0 0.0.0.3 area 0

R4(config)#router ospf 10
R4(config-router)#router-id 4.4.4.4
R4(config-router)#network 4.0.0.0 0.255.255.255 area 0
R4(config-router)#network 10.0.0.0 0.0.0.3 area 0
R4(config-router)#network 192.168.3.0 0.0.0.255 area 0


R1(config-router)#area 1 virtual-link 2.2.2.2
R2(config-router)#area 1 virtual-link 1.1.1.1

R3(config)#do show ip route
     1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/3] via 10.0.0.9, 00:00:42, FastEthernet0/0
     2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/2] via 10.0.0.9, 00:00:42, FastEthernet0/0
     3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
     4.0.0.0/32 is subnetted, 1 subnets
O IA    4.4.4.4 [110/4] via 10.0.0.9, 00:00:32, FastEthernet0/0
     10.0.0.0/30 is subnetted, 3 subnets
C       10.0.0.8 is directly connected, FastEthernet0/0
O IA    10.0.0.0 [110/3] via 10.0.0.9, 00:00:34, FastEthernet0/0
O IA    10.0.0.4 [110/2] via 10.0.0.9, 00:00:44, FastEthernet0/0
     192.168.0.0/32 is subnetted, 1 subnets
O IA    192.168.0.1 [110/3] via 10.0.0.9, 00:00:45, FastEthernet0/0
     192.168.1.0/32 is subnetted, 1 subnets
O IA    192.168.1.1 [110/2] via 10.0.0.9, 00:00:45, FastEthernet0/0
C    192.168.2.0/24 is directly connected, Loopback1
     192.168.3.0/32 is subnetted, 1 subnets
O IA    192.168.3.1 [110/4] via 10.0.0.9, 00:00:35, FastEthernet0/0

R3(config)#do ping 4.4.4.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 88/129/180 ms