From: Jonathan Morton <chromatix99@gmail.com>
To: Dave Taht <dave.taht@gmail.com>
Cc: ECN-Sane <ecn-sane@lists.bufferbloat.net>
Subject: Re: [Ecn-sane] cautionary tcp tale
Date: Tue, 13 Aug 2019 02:37:06 +0300 [thread overview]
Message-ID: <A1C9D789-2084-4705-B61F-975073450368@gmail.com> (raw)
In-Reply-To: <CAA93jw7gG9kkmx+b=KMXkTRMswQsMUx=yy1TCs45cSUh6Az3LQ@mail.gmail.com>
> On 13 Aug, 2019, at 12:30 am, Dave Taht <dave.taht@gmail.com> wrote:
>
> https://www.snellman.net/blog/archive/2017-07-20-s3-mystery/
TL;DR summary:
Buggy checksum recalculation in a cable modem caused minor packet loss (through rejection at the receiver). In the absence of TCP Timestamps, the retransmissions of these lost packets were identical and triggered the same bug. Result, connections to certain particular servers which had the unusual property of disabling TCP Timestamps would quickly stall.
I think a tool could be made to watch a sample of received traffic for this pattern: incorrect checksums where the correct checksum is the same each time (though different per deployment). How much network equipment exhibits this bug?
- Jonathan Morton
next prev parent reply other threads:[~2019-08-12 23:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 21:30 Dave Taht
2019-08-12 23:37 ` Jonathan Morton [this message]
2019-08-13 0:49 ` David P. Reed
2019-08-13 1:01 ` Rodney W. Grimes
2019-08-13 1:38 ` Jonathan Morton
2019-08-13 16:39 ` Michael Richardson
2019-08-13 20:28 ` David P. Reed
2019-08-13 21:21 ` Rodney W. Grimes
2019-08-14 2:26 ` David P. Reed
2019-08-14 2:46 ` Rodney W. Grimes
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