FreeBSD NFS server not responding to TCP SYN packets from Linux/SunOS clients

[Nicolas KOWALSKI]

on at cs.ait.ac.th writes:

> Nicolas KOWALSKI wrote:
>> Our FreeBSD 4.10 NFS server has some problems serving files by NFS on
>> TCP (no problem with UDP) when the Linux (2.6) or Solaris (5.9)
>> clients shut down in an unclean manner (power failure). When the
>> clients try to mount the shares from the server after an
>> unclean shutdown, the mount process hang during several minutes (delay
>> is varying), then succeeds.
>
> That is just a wild guess, but NFS mounting would happen always at
> the same stage of the boot, so maybe with the same source port
> number and you could be facing the problem that the connection is
> waiting for termination on the server (close_wait or fin_wait or
> something)... Se source port in working example is 798 and source
> port in failing example is 799 certainly not random.

This is certainly right. 

So, what can I do to make the server not wait so long for the
connection termination ? Is there a TTL parameter I can adjust
somewhere ?

Thanks,
-- 
Nicolas