26、OSPF配置實驗之不規則區域虛鏈路

1、實驗拓撲

按拓撲所示配置好OSPF后，此時由于area2與area0之間隔著area1,此時area2中的R5并沒有路由可達area3、area0、area1。為此我們在R3、R4上建立一條虛鏈路即可。

2、實驗配置

R1配置

interface Loopback0

 ip address 1.1.1.1 255.255.255.0

interface Serial0/0

 ip address 12.1.1.1 255.255.255.0

router ospf 110

 router-id 1.1.1.1

 network 1.1.1.0 0.0.0.255 area 3

 network 12.1.1.0 0.0.0.255 area 3

R2配置

interface Loopback0

 ip address 2.2.2.2 255.255.255.0

interface Serial0/0

 ip address 12.1.1.2 255.255.255.0

interface Serial0/1

 ip address 23.1.1.2 255.255.255.0

router ospf 110

 router-id 2.2.2.2

 network 2.2.2.0 0.0.0.255 area 0

 network 12.1.1.0 0.0.0.255 area 3

 network 23.1.1.0 0.0.0.255 area 0

R3配置

interface Loopback0

 ip address 3.3.3.3 255.255.255.0

interface Serial0/0

 ip address 34.1.1.3 255.255.255.0

interface Serial0/1

 ip address 23.1.1.3 255.255.255.0

router ospf 110

 router-id 3.3.3.3

 network 3.3.3.0 0.0.0.255 area 0

 network 23.1.1.0 0.0.0.255 area 0

 network 34.1.1.0 0.0.0.255 area 1

R4配置

interface Loopback0

 ip address 4.4.4.4 255.255.255.0

interface Serial0/0

 ip address 34.1.1.4 255.255.255.0

interface Serial0/1

 ip address 45.1.1.4 255.255.255.0

router ospf 110

 router-id 4.4.4.4

 log-adjacency-changes

 network 4.4.4.0 0.0.0.255 area 1

 network 34.1.1.0 0.0.0.255 area 1

 network 45.1.1.0 0.0.0.255 area 2

R5配置

interface Loopback0

 ip address 5.5.5.5 255.255.255.0

interface Serial0/1

 ip address 45.1.1.5 255.255.255.0

router ospf 110

 router-id 5.5.5.5

 log-adjacency-changes

 network 5.5.5.0 0.0.0.255 area 2

 network 45.1.1.0 0.0.0.255 area 2

3、配置OSPF虛鏈路

此時R1和R5都沒有彼此的路由。我們將R3、R4上做如下修改

R3配置

router ospf 110

 area 1 virtual-link 4.4.4.4

R4配置

router ospf 110

 area 1 virtual-link 3.3.3.3