Cannot list a particular directory through NFS with UDP

[Jeremie Le Hen]

Rick,

Thanks for your time on this.

On Thu, Dec 31, 2009 at 02:23:32PM -0500, Rick Macklem wrote:
> [stuff snipped]
> >> This appears to be the reply to the nfs readdir request, which is what
> >> would be expected. It could be a problem with the content or the reply
> >> or a NetBSD client issue.
> >>
> >> If you were to email me the raw tcpdump capture for the above, I could
> >> take a look at it in wireshark (which knows how to interpret nfs) and
> >> see if there is anything bogus looking in the reply.
> >> ("tcpdump -s 0 -w <file> host 192.168.1.1" and then email me <file> as an
> >> attachment, should do it)
> >
> > You will find the pcap file attached.
> >
> Well, I looked at it under wireshark and the readdir reply looks fine.
> (It is made up of two IP fragments, but wireshark reassembles them ok
> and says the checksums are ok. The contents look like a valid Readdir
> RPC reply.) Maybe NetBSD doesn't reassemble the IP fragments correctly
> or has an issue w.r.t. the checksum, but Wireshark thinks it's aok.

I will reduce the MTU and see if the problem arises with directories
that could be read correctly otherwise.  I will keep you informed.

Does NFS permit to fragment/reassemble at the application layer?

> ps: I vaguely recall that the problem went away when you used TCP
>      instead. Is that correct?

Yes this is correct.

Regards,
-- 
Jeremie Le Hen

Humans are born free and equal.  But some are more equal than the others.
					    Coluche