non-existent neighbor id ospf

[kapydan88]

Hello for everybody.

Has anyone faced situation that the isr4331 router establishes a neighborhood with another router isr4331 with a non-existent router id...

[Richard Burts]

I am not clear about what you are asking about non-existent router id.

- are you saying that OSPF config does not specify a router id? That is common and OSPF will pick an address from one of the interface addresses.

- are you saying that OSPF config does specify a router id and that the address specified as router id is not an IP address of any interface on the router? That is not as common. But it is not a problem. 

Sometimes when I am setting up a lab exercise that uses OSPF I will specify router id for first router as 1.1.1.1, the router id for second router as 2.2.2.2, the router id for third router as 3.3.3.3 etc to make it easier to keep track of who the router is talking to. It works just find.

[kapydan88]

Sorry, its my mistake. It looks, like i resolved this problem. This is no non-existent neighbor id ospf, but old neighbor id ospf.

There is dmvpn network of 6 spokes and 1 hub. Initially, when ospf was implemented, there was a different addressing scheme from the current one. And the hub had the largest address 172.16.1.1, which was then replaced with a new router-id 10.11.124.1. However, despite the removal of the old largest address 172.16.1.1 and the assignment of the router-id, the spokes see the hub as 172.16.1.1.

[MHM Cisco World]

thanks for share solution.

[kapydan88]

But i don't understand why spoke see old router-id from hubs side? We changed it about 6 months or even more and after this moment routers were rebooted several times.

[Richard Burts]

The original poster tells us " the spokes see the hub as 172.16.1.1" My first thought is to ask whether this is true on all hubs, or only on some hubs (or even on a single hub)?

[kapydan88]

Sorry for late answer.

My first thought is to ask whether this is true on all hubs, or only on some hubs (or even on a single hub)? - yes, its correct. There is one hub ISR4431 and few spokes ISR4331 (all with the same software version isr4300-universalk9.17.05.01a.SPA). All spokes see hub with old router-id. 

[Richard Burts]

Thanks for the additional information. Would you post the output of these commands from the hub and from one of the spokes:

show ip ospf
show ip ospf interface

[kapydan88]

This problem was solved by resetting ospf process and "clear ip ospf neigh"

[Richard Burts]

Thanks for the update. Glad to know that the issue is resolved. It was a fairly simple solution to reset the process and to clear the neighbors. Thanks for sharing the solution.