Ospf neighboring. Mismatch

fzink · ‎03-31-2003

All,

In an OSPF area some of the adjacences experiment issue. The problem occurs between 2 3640 linked together thanks to a switch 2950. The router display the following log and then restart the adjacence properly.

03:57:29: %OSPF-5-ADJCHG: Process 3, Nbr 192.160.255.115 on FastEthernet0/0 from FULL to EXSTART, SeqNumberMismatch

Noticed that the adjacence is actually never down therefore it receives the Hello packet. I didn't find any information about that mismatch log. Is it regarding the LSA sequence number, the neighbor ID or something else?

Thank you to provide me that information

pbarman · ‎03-31-2003

The message says that the OSPF neighbor was changed state from FULL to EXSTART because of the receipt of a Database Description packet from the neighbor with an Unexpected sequence number. How often do you get this message?

fzink · ‎03-31-2003

I receive that message 2 or 3 times by day. Does it means that the packet are corrupted or that there are many losts which implies that the sequence number are not synchronized?