OSPFv3 Log Adjacency Changes Output

[VZN418722]

What is the log output that I should be seeing with "log adjacency changes" configured? Should I only be seeing LOADING to FULL and FULL to DOWN? I do not have "log adjacency changes detail" configured on an ASR9000 but I receive these state change messages that include EXSTART to DOWN and DOWN to DOWN.

RP/0/RSP0/CPU0:Mar 20 09:25:49.141 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from LOADING to FULL, Loading Done

RP/0/RSP0/CPU0:Mar 20 09:29:38.513 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from FULL to DOWN, Neighbor Down: Dead timer expired

RP/0/RSP0/CPU0:Mar 20 09:30:09.406 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from EXSTART to DOWN, Neighbor Down: Too many DBD retransmissions

RP/0/RSP0/CPU0:Mar 20 09:31:07.142 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from DOWN to DOWN, Neighbor Down: Ignore timer expired

RP/0/RSP0/CPU0:Mar 20 09:32:20.472 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from EXSTART to DOWN, Neighbor Down: Too many DBD retransmissions

RP/0/RSP0/CPU0:Mar 20 09:33:15.985 EDT: ospfv3[1021]: %ROUTING-OSPFv3-5-ADJCHG : Process 6000, Nbr 104.255.45.102 on GigabitEthernet

0/2/0/1 from DOWN to DOWN, Neighbor Down: Ignore timer expired

[Nandan Mathure]

@VZN418722

With "detail" keyword added it will show you all the  transition through all states like down, attempt Init 2-way extart  exchange loading and full.

In the above output we are just seeing the adjacency is flapping eg. LOADING to FULL, FULL to DOWN, EXSTART to DOWN, DOWN to DOWN, etc. Most likely cause Network type mismatch .

Plz let me know if this helped.

[VZN418722]

All right. But I do not want to be seeing "detail" messages. Are EXSTART to DOWN and DOWN to DOWN considered "detail" messages? In other words, is the router behaving incorrectly by displaying those messages when I do not have "detail" configured?

[Nandan Mathure · Accepted solution]

The messages that you are seeing are showing adjacency issue between ospf speakers. Those are seen when we have just have "log-adjacency-changes" under the routing process.

So its not a detailed output but states are changing due to some mismatch mostly mtu (ipv6 ospf mtu-ignore) should help.

Is "debug ipv6 ospf adjacency" possible ? if yes then you can check the output to figure out whats the reason for the flap.

[VZN418722]

I already know the reason for the adjacency flap. I just was not sure if the router was displaying the correct log message output according to its configuration. Thank you.

[RUSTOM BILLIMORIA]

Hi could you provide me details about the devices that are trying to form this ospf neighborship.

details like model no and ios versions.