[BSCI]配置OSPF虚链路

R1配置
r1(config)#int s2/1
r1(config-if)#ip ad 12.0.0.1 255.255.255.0
r1(config-if)#no sh
r1(config-if)#exi
r1(config)#router os 100
r1(config-router)#net 12.0.0.1 0.0.0.0 a 0
r1(config-router)#end

R2配置
r2(config)#int s2/1
r2(config-if)#ip ad 12.0.0.2 255.255.255.0
r2(config-if)#no sh
r2(config)#int s2/2
r2(config-if)#ip ad 23.0.0.2 255.255.255.0
r2(config-if)#no sh
r2(config-if)#exi
r2(config)#router os 100
r2(config-router)#net 12.0.0.2 0.0.0.0 a 0
r2(config-router)#net 23.0.0.2 0.0.0.0 a 1
r2(config-router)#end

R3配置
r3(config)#int s2/1
r3(config-if)#ip ad 23.0.0.3 255.255.255.0
r3(config-if)#no sh
r3(config-if)#int s2/2
r3(config-if)#ip ad 34.0.0.3 255.255.255.0
r3(config-if)#no sh
r3(config-if)#exi
r3(config)#router os 100
r3(config-router)#net 23.0.0.3 0.0.0.0 a 1
r3(config-router)#net 34.0.0.3 0.0.0.0 a 1
r3(config-router)#end

R4配置
r4(config)#int s2/1
r4(config-if)#ip ad 34.0.0.4 255.255.255.0
r4(config-if)#no sh
r4(config-if)#int s2/2
r4(config-if)#ip ad 45.0.0.4 255.255.255.0
r4(config-if)#no sh
r4(config-if)#exi
r4(config)#router os 100
r4(config-router)#net 34.0.0.4 0.0.0.0 a 1
r4(config-router)#net 45.0.0.4 0.0.0.0 a 0
r4(config-router)#end

R5配置
r5(config)#int s2/2
r5(config-if)#ip ad 45.0.0.5 255.255.255.0
r5(config-if)#no sh
r5(config-if)#exi
r5(config)#router os 100
r5(config-router)#net 45.0.0.5 0.0.0.0 a 0
r5(config-router)#end

R2配置虚链路
r2(config)#router ospf 100
r2(config-router)#area 1 virtual-link 45.0.0.4

R4配置虚链路
r4(config)#router os 100
r4(config-router)#area 1 v 23.0.0.2 

如果一端配置错误，系统错误提示信息如下
*Jul 23 15:55:06.999: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 34.0.0.4, Serial2/2
r2(config-router)#
*Jul 23 15:55:16.943: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 34.0.0.4, Serial2/2
r2(config-router)#
*Jul 23 15:55:26.959: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 34.0.0.4, Serial2/2
r2(config-router)#
*Jul 23 15:55:36.943: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 34.0.0.4, Serial2/2

显示虚链路信息
r4#sh ip os v
Virtual Link OSPF_VL0 to router 23.0.0.2 is up
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 1, via interface Serial2/1, Cost of using 128
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:02