Does OSPF Process id need to match?

Henry Ocansey

i'm leaning for my ccnp and know that OSPF process ID is a locally significant number that do not need to match for neighbor adj to form.
But i just tried this on gns3 and it did NOT work. One router running process id 1 and other running process is 2 did not form neighbor untill i changed for them to match...can anyone confirm?

Ronnie Wong

@Henry-Ocansey,

There may be some other issue possibly with GNS3. But I'm not sure.

With OSPF, the process-id numbers are only locally significant to the router itself. So it's not a value that is passed between OSPF neighbors.

So, with GNS3, I have ITProTV-1 with OSPF 1 and ITProTV-2 with OSPF 1. The adjacency formed between them:

ITProTV-R1(config-if)#
*Sep 14 09:30:37.823: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done
ITProTV-R2#
*Sep 14 09:30:37.740: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done

I changed the process-id for ITProTV-1 to 999

ITProTV-R1(config)#no router ospf 1
ITProTV-R1(config)#
*Sep 14 09:31:42.239: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
ITProTV-R1(config)#router ospf 999
ITProTV-R1(config-router)#network 0.0.0.0 255.255.255.255 area 0
ITProTV-R1(config-router)#
*Sep 14 09:32:12.320: %OSPF-5-ADJCHG: Process 999, Nbr 2.2.2.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done

ITProTV-2#
*Sep 14 09:32:12.230: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done

Henry Ocansey

@Ronnie-Wong thanks very much. I had to restart gns3 and its ok now..