掌握如何配置ospf虚链路
实验拓扑：
R1上配置
R1#ping 34.0.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 34.0.0.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 60/89/136 ms
R1#ping 34.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 34.0.0.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R5上配置
R5#ping 23.0.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 23.0.0.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R5#ping 23.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 23.0.0.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 76/111/164 ms
配置缘由：
由于在不同区域间路由不能学习宣告，所以以上ping不能通信。为了使其可以通信所以在r2，r4上配置虚拟链路实现跨区域的通信
配置成功后的表现
R4#ping 12.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 12.0.0.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 80/99/156 ms
R4#ping 23.0.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 23.0.0.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 48/73/136 ms
R4#ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 92/420/1624 ms
实际的配置关键
R4(config)#router ospf 64
R4(config-router)#area 1 virtual-link 12.0.0.2 指定路由的ID
R2(config)#router ospf 64
R2(config-router)#area 1 virtual-link 45.0.0.1 指定路由的ID
R2(config-router)#^Z
R4#sh ip ospf virtual-links 查看虚链路连接情况
Virtual Link OSPF_VL1 to router 12.0.0.2 is up 连接成功
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 00:00:07
Adjacency State FULL (Hello suppressed)
Index 1/3, retransmission queue length 0, number of retransmission 1
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 1, maximum is 1
Last retransmission scan time is 0 msec, maximum is 0 msec
Virtual Link OSPF_VL0 to router 23.0.0.1 is down
Run as demand circuit
DoNotAge LSA allowed.
Transit area 1, Cost of using 65535
Transmit Delay is 1 sec, State DOWN,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
S2/1为r2的路由id，s2/2为r4的路由id
|
R2 |
R4 |
虚拟链路状态 |
|
S2/1 |
S2/1 |
不通 |
|
S2/1 |
S2/2 |
通 |
|
S2/2 |
S2/1 |
不通 |
|
S2/2 |
S2/2 |
不通 |
