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

[on at cs.ait.ac.th]

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.

Olivier