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Sequence mismatch occurred during OSPF neighbor establishment process

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TitleSequence mismatch occurred during OSPF neighbor establishment process
Symptoms
Customer is experiencing OSPF neighbor establishment and found the log like below.

MM/DD/YYYY HH:MM:00.00 <Warn:ospf.neighbor.ProcDDFail> Processing DD from netighbor 16x.xxx.yyy.zz fails on NBR seqmismatch event,case else.

 
Environment
EXOS
OSPF
Cause
From page 88 of RFC2328

SeqNumberMismatch
 A Database Description packet has been received that either a) has an unexpected DD sequence number, b) unexpectedly has the Init bit set or c) has an Options field differing from the last Options field received in a Database Description packet.  Any of these conditions indicate that some error has occurred during adjacency establishment.
 
During the neighbor establishment process, there is another update of LSAs which is now different than what they exchanged during the process.
Resolution
Keep OSPF network stable.

Isolate two neighbors from the network and establish OSPF neighbor and make them connected to the network
Additional notes

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