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Ospf exchange state

Hello together,

we are managing a a large ospf network environment (about 80 areas). Since a few days we have problems with some neighbors. The associated neighbor state remains still in exchange state. At the error log we recognized that there are many LSA retransmissions.

Is there an possibility to adjust any LSA timer so that the neighbor state change to full ??

Or can we block some LSA´s at the ABR/ASBR. So that the exchange of the LSA`s is faster ??

Or do you have an another idea what the reason could be ??

We checked the Line utilization, and this was normal. Also an clear ospf neighbor was not successful.

Thanks in advance.


Re: Ospf exchange state

I would try a debug ip ospf adj before I start messing with timers and such.... It could be something simpler than not being able to get all the LSA's across the link.



Re: Ospf exchange state

There are several reasons that cause neighbors being stuck in exstart

1. unicast is broken

2. On a wide area link the PVC or VC is not mapped properly

3. MTU mismatch

4. Acess-list blocking unicast

5.Nat is translating the unicast

6. routers have same RID