OSPF 虚链路

通过配置OSPF虚链路连接到骨干区域。

实验拓扑

如图所示连接，地址规划如下：

配置方法

R2(config)#router ospf 1  R2(config-router)#area 1 virtual-link 3.3.3.3  R2(config-router)#ex  

配置过程

R1

R1#conf t  Enter configuration commands, one per line.  End with CNTL/Z.  R1(config)#int f0/0  R1(config-if)#ip add 192.168.10.1 255.255.255.0  R1(config-if)#no sh  R1(config-if)#ex  R1(config)#int f0/1  R1(config-if)#ip add 192.168.20.1 255.255.255.0  R1(config-if)#no sh  R1(config-if)#ex  R1(config)#int loopback 0  R1(config-if)#ip add 1.1.1.1 255.255.255.255  R1(config-if)#no sh  R1(config-if)#ex  R1(config)#router ospf 1  R1(config-router)#router-id 1.1.1.1  R1(config-router)#network 192.168.10.0 0.0.0.255 area 2  R1(config-router)#network 192.168.20.0 0.0.0.255 area 2  R1(config-router)#ex  

R2

R2#conf t  Enter configuration commands, one per line.  End with CNTL/Z.  R2(config)#int f0/0  R2(config-if)#ip add 192.168.20.2 255.255.255.0  R2(config-if)#no sh  R2(config-if)#ex  R2(config)#int f0/1  R2(config-if)#ip add 192.168.30.1 255.255.255.0  R2(config-if)#no sh  R2(config-if)#ex  R2(config)#int loopback 0  R2(config-if)#ip add 2.2.2.2 255.255.255.255  R2(config-if)#no sh  R2(config-if)#ex  R2(config)#router ospf 1  R2(config-router)#router-id 2.2.2.2  R2(config-router)#network 192.168.20.0 0.0.0.255 area 2  R2(config-router)#network 192.168.30.0 0.0.0.255 area 1  R2(config-router)#ex  

R3

R3#conf t  Enter configuration commands, one per line.  End with CNTL/Z.  R3(config)#int f0/0  R3(config-if)#ip add 192.168.30.2 255.255.255.0  R3(config-if)#no sh  R3(config-if)#ex  R3(config)#int f0/1  R3(config-if)#ip add 192.168.40.1 255.255.255.0  R3(config-if)#no sh  R3(config-if)#ex  R3(config)#int loopback 0  R3(config-if)#ip add 3.3.3.3 255.255.255.255  R3(config-if)#no sh  R3(config-if)#ex  R3(config)#router ospf 1  R3(config-router)#router-id 3.3.3.3  R3(config-router)#network 192.168.30.0 0.0.0.255 area 1  R3(config-router)#network 192.168.40.0 0.0.0.255 area 0  R3(config-router)#ex  

R4

R4#conf t  Enter configuration commands, one per line.  End with CNTL/Z.  R4(config)#int f0/0  R4(config-if)#ip add 192.168.40.2 255.255.255.0  R4(config-if)#no sh  R4(config-if)#ex  R4(config)#int f0/1  R4(config-if)#ip add 192.168.50.1 255.255.255.0  R4(config-if)#no sh  R4(config-if)#ex  R4(config)#int loopback 0  R4(config-if)#ip add 4.4.4.4 255.255.255.255  R4(config-if)#no sh  R4(config-if)#ex  R4(config)#router ospf 1  R4(config-router)#router-id 4.4.4.4  R4(config-router)#network 192.168.40.0 0.0.0.255 area 0  R4(config-router)#network 192.168.50.0 0.0.0.255 area 0  R4(config-router)#ex  

第一次查看路由表

• R1

R1(config)#do show 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         1.0.0.0/32 is subnetted, 1 subnets  C       1.1.1.1 is directly connected, Loopback0  C    192.168.10.0/24 is directly connected, FastEthernet0/0  C    192.168.20.0/24 is directly connected, FastEthernet0/1  

• R2

R2(config)#do show 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         2.0.0.0/32 is subnetted, 1 subnets  C       2.2.2.2 is directly connected, Loopback0  C    192.168.30.0/24 is directly connected, FastEthernet0/1  O    192.168.10.0/24 [110/20] via 192.168.20.1, 00:09:52, FastEthernet0/0  O IA 192.168.40.0/24 [110/20] via 192.168.30.2, 00:05:59, FastEthernet0/1  C    192.168.20.0/24 is directly connected, FastEthernet0/0  O IA 192.168.50.0/24 [110/30] via 192.168.30.2, 00:01:42, FastEthernet0/1  

• R3

R3(config)#do show 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         3.0.0.0/32 is subnetted, 1 subnets  C       3.3.3.3 is directly connected, Loopback0  C    192.168.30.0/24 is directly connected, FastEthernet0/0  C    192.168.40.0/24 is directly connected, FastEthernet0/1  O    192.168.50.0/24 [110/20] via 192.168.40.2, 00:02:01, FastEthernet0/1  

• R4

R4(config)#do show 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    O IA 192.168.30.0/24 [110/20] via 192.168.40.1, 00:02:27, FastEthernet0/0       4.0.0.0/32 is subnetted, 1 subnets  C       4.4.4.4 is directly connected, Loopback0  C    192.168.40.0/24 is directly connected, FastEthernet0/0  C    192.168.50.0/24 is directly connected, FastEthernet0/1  

配置虚链路

R2(config)#router ospf 1  R2(config-router)#area 1 virtual-link 3.3.3.3  R2(config-router)#ex  

R3(config)#router ospf 1  R3(config-router)#area 1 virtual-link 2.2.2.2  R3(config-router)#ex  

第二次查看路由表

R1(config)#do show 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         1.0.0.0/32 is subnetted, 1 subnets  C       1.1.1.1 is directly connected, Loopback0  O IA 192.168.30.0/24 [110/20] via 192.168.20.2, 00:02:08, FastEthernet0/1  C    192.168.10.0/24 is directly connected, FastEthernet0/0  O IA 192.168.40.0/24 [110/30] via 192.168.20.2, 00:01:27, FastEthernet0/1  C    192.168.20.0/24 is directly connected, FastEthernet0/1  O IA 192.168.50.0/24 [110/40] via 192.168.20.2, 00:01:27, FastEthernet0/1  

R2(config)#do show 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         2.0.0.0/32 is subnetted, 1 subnets  C       2.2.2.2 is directly connected, Loopback0  C    192.168.30.0/24 is directly connected, FastEthernet0/1  O    192.168.10.0/24 [110/20] via 192.168.20.1, 00:02:19, FastEthernet0/0  O    192.168.40.0/24 [110/20] via 192.168.30.2, 00:01:33, FastEthernet0/1  C    192.168.20.0/24 is directly connected, FastEthernet0/0  O    192.168.50.0/24 [110/30] via 192.168.30.2, 00:01:33, FastEthernet0/1  

R3(config)#do show 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         3.0.0.0/32 is subnetted, 1 subnets  C       3.3.3.3 is directly connected, Loopback0  C    192.168.30.0/24 is directly connected, FastEthernet0/0  O IA 192.168.10.0/24 [110/30] via 192.168.30.1, 00:01:39, FastEthernet0/0  C    192.168.40.0/24 is directly connected, FastEthernet0/1  O IA 192.168.20.0/24 [110/20] via 192.168.30.1, 00:01:39, FastEthernet0/0  O    192.168.50.0/24 [110/20] via 192.168.40.2, 00:08:17, FastEthernet0/1  

R4(config)#do show 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    O IA 192.168.30.0/24 [110/20] via 192.168.40.1, 00:08:32, FastEthernet0/0       4.0.0.0/32 is subnetted, 1 subnets  C       4.4.4.4 is directly connected, Loopback0  O IA 192.168.10.0/24 [110/40] via 192.168.40.1, 00:01:34, FastEthernet0/0  C    192.168.40.0/24 is directly connected, FastEthernet0/0  O IA 192.168.20.0/24 [110/30] via 192.168.40.1, 00:01:34, FastEthernet0/0  C    192.168.50.0/24 is directly connected, FastEthernet0/1  

验证结果

配置 IP 地址

PC1> ip 192.168.10.2 192.168.10.1  Checking for duplicate address...  PC1 : 192.168.10.2 255.255.255.0 gateway 192.168.10.1  

PC2> ip 192.168.50.2 192.168.50.1  Checking for duplicate address...  PC1 : 192.168.50.2 255.255.255.0 gateway 192.168.50.1  

ping 测试

PC1> ping 192.168.50.2  192.168.50.2 icmp_seq=1 timeout  84 bytes from 192.168.50.2 icmp_seq=2 ttl=60 time=85.890 ms  84 bytes from 192.168.50.2 icmp_seq=3 ttl=60 time=80.743 ms  84 bytes from 192.168.50.2 icmp_seq=4 ttl=60 time=83.772 ms  84 bytes from 192.168.50.2 icmp_seq=5 ttl=60 time=85.761 ms  

PC2> ping 192.168.10.2  84 bytes from 192.168.10.2 icmp_seq=1 ttl=60 time=76.961 ms  84 bytes from 192.168.10.2 icmp_seq=2 ttl=60 time=84.788 ms  84 bytes from 192.168.10.2 icmp_seq=3 ttl=60 time=79.753 ms  84 bytes from 192.168.10.2 icmp_seq=4 ttl=60 time=77.792 ms  84 bytes from 192.168.10.2 icmp_seq=5 ttl=60 time=83.964 ms