Alan Cox suggested that I forward this here.
----- Original Message -----
From: "Marty Poulin" <mpoulin@xxxxxxxxxxx>
To: "Linux-Kernel" <linux-kernel@xxxxxxxxxxxxxxx>
Sent: Thursday, July 26, 2001 3:19 PM
Subject: oops/bug in tcp, SACK doesn't work?
> Perhaps this has been covered somewhere before, but for some reason it
> doesn't look like the 2.4.7 (and previous 2.4.x?) kernels responds to
SACK
> correctly. Instead of just resending the missing packet Linux resends the
> entire packet stream as if it never received the SACK.
>
> Only reason I noticed this was that I was debugging connection problems
with
> our servers that were running 2.4.5. I didn't figure the problem out for
> several days, when I exhausted all else I decided it must be the checksum
of
> the retransmitted packets. With that in hand a simple google search
turned
> up that there was already a patch for this included in the 2.4.7 kernel.
> Doh!
>
> Hence I am now scanning through 100-200 emails a day with the rest of you
> just trying to keep up on the issues and bugs that affect me. There must
be
> a place to look for current and fixed bugs without pouring over change
logs
> and the entire mailing list?
>
> In any case both of these problems were easily duplicated with three
> machines. One of the machines was used as a router running NIST net
emulator
> ( http://snad.ncsl.nist.gov/itg/nistnet/ ) that allows you to set packet
> delay, bandwidth and loss. This is a free implementation for Linux that
is
> currently in useable alpha (yup sometimes it crashes the router when
> loaded), but hey it works reliable enough to get some testing done.
>
>
> Marty Poulin
> vandal@xxxxxxxxxxx
> Lead Programmer
> Host/Client Communications
> Playnet Inc./Cornered Rat Software
>
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