Re: [PATCH] spidernet: Fix problem sending IP fragments

On Monday, 12. March 2007 09:28, Geert Uytterhoeven wrote:

On Sat, 10 Mar 2007, Norbert Eicker wrote:

quoted

On Friday, 9. March 2007 17:53, Jeff Garzik wrote:

quoted

Linas Vepstas wrote:

quoted

Please apply. The rather long patch description is from the
submitter, Norbert Eicker, I don't know if that's alright, or
if I should ask to have it trimmed.

Thanks,
--linas

From: Norbert Eicker <redacted>


Signed-off-by: Norbert Eicker <redacted>
Signed-off-by: Linas Vepstas <redacted>

are you sure it can't send out fragmented IP frames?  what's
really going on here?

Pretty sure that fragmented IP frames are not send out. Here's a
small test using ttcp and tcpdump reproducing the problem (I assume
a MTU of 1500):

Hence if I understand that correctly, NFS over UDP doesn't work at
all as NFS uses 8 KiB UDP packets by default?

NFS seems to work but considering what I saw in tcpdump it uses TCP 
instead of UDP. I have not yet found out why NFS seems to default to 
TCP on Cell (the man-pages claims that UDP is the default).

If I explicitely demand to use UDP it indeed does not work at all.

Again if I use tcpdump on both sides, I see that the NFS-server claims 
to send out IP fragments containing the UDP datagrams (larger than 
MTU). The NFS-client does not see any of these fragments.

Using the patched spidernet module makes NFS work like a charm.


Norbert
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