How to configure OSPF Virtual Link

Lessons Discussion
55

Hi Zeko,

If you enable authentication for virtual links, you have to enable it globally for area 0 and set the password on the virtual link command. Here’s an example:

R1#show run | begin ospf
router ospf 1
 area 0 authentication
 area 1 virtual-link 2.2.2.2 authentication-key NWL

Authentication is enabled for area 0, the virtual link goes through area 1 and has the password. You can see it works with this command:

R1#show ip ospf virtual-links 
Virtual Link OSPF_VL0 to router 192.168.23.2 is up
  Run as demand circuit
  DoNotAge LSA allowed.
  Transit area 1, via interface GigabitEthernet0/1
 Topology-MTID    Cost    Disabled     Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:04
    Adjacency State FULL (Hello suppressed)
    Index 1/1/2, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec
  Simple password authentication enabled

Note the last line that says simple password authentication enabled.

Hope this helps!

Rene

2 Likes