From: Norman Wilson <norman@oclsc.org>
To: tuhs@tuhs.org
Subject: Re: [TUHS] [SPAM] Re: SCCS
Date: Fri, 13 Sep 2019 18:01:14 -0400 [thread overview]
Message-ID: <1568412078.22454.for-standards-violators@oclsc.org> (raw)
Peter Jeremy:
> NFS ran much faster when you turned off the UDP checksums as well.
> (Though there was still the Ethernet CRC32).
Dave Horsfall:
Blerk... That just tells you that the packet came across the wire more or
less OK.
=====
UDP (and TCP) checksums are nearly useless against
the sort of corruption Larry described. Since they
are a simple addition with carry wraparound, you
can insert or remove any number of word-aligned pairs
of zero octets without the checksum changing.
I discovered this the hard way, while tracking down
a kernel bug that caused exactly that sort of corruption.
Does IPv6 require a meaningful checksum, or just the
useless old ritual one?
Norman Wilson
Toronto ON
next reply other threads:[~2019-09-13 22:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-13 22:01 Norman Wilson [this message]
2019-09-13 22:30 ` Dave Horsfall
2019-09-16 10:59 ` Tony Finch
2019-09-16 12:11 ` Leah Neukirchen
2019-09-16 21:45 ` Dave Horsfall
2019-09-16 22:21 ` George Michaelson
-- strict thread matches above, loose matches on Subject: below --
2019-09-09 6:25 [TUHS] PWB vs Unix/TS Warner Losh
2019-09-10 15:16 ` Clem Cole
2019-09-11 3:53 ` Warner Losh
2019-09-11 15:36 ` Clem Cole
2019-09-11 18:11 ` Larry McVoy
2019-09-11 22:49 ` Dave Horsfall
2019-09-12 3:43 ` [TUHS] SCCS Larry McVoy
2019-09-12 4:20 ` George Michaelson
2019-09-12 4:31 ` [TUHS] [SPAM] SCCS Larry McVoy
2019-09-12 13:44 ` Tony Finch
2019-09-13 4:11 ` Larry McVoy
2019-09-13 5:54 ` Dave Horsfall
2019-09-13 8:00 ` Peter Jeremy
2019-09-13 15:23 ` Larry McVoy
2019-09-13 21:36 ` Dave Horsfall
2019-09-12 4:28 ` [TUHS] SCCS Jon Forrest
2019-09-12 16:45 ` Eric Allman
2019-09-12 17:29 ` Clem Cole
2019-09-13 8:12 ` emanuel stiebler
2019-09-13 21:11 ` Steffen Nurpmeso
2019-09-13 21:17 ` Larry McVoy
2019-09-13 23:03 ` Steffen Nurpmeso
2019-09-14 1:55 ` [TUHS] [SPAM] SCCS Larry McVoy
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