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RE: TCP Checksum Interoperability

Lloyd Wood <l.wood@eim.surrey.ac.uk> Fri, 05 April 2002 20:44 UTC

Date: Fri, 5 Apr 2002 21:44:42 +0100 (BST)
From: Lloyd Wood <l.wood@eim.surrey.ac.uk>
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To: Michael Smith <msmith@corp.iready.com>
Cc: "'CTrobridge@baltimore.com'" <CTrobridge@baltimore.com>, "'sra+ietf@hactrn.net'" <sra+ietf@hactrn.net>, "'ietf@IETF.ORG'" <ietf@IETF.ORG>, "'tcp-impl@grc.nasa.gov'" <tcp-impl@grc.nasa.gov>
Subject: RE: TCP Checksum Interoperability
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On Fri, 5 Apr 2002, Michael Smith wrote:

> The last time this came up for a TCP implementation I used to
> maintain, our interpretation of Robustness Principle applied to this
> problem dictated that we shouldn't send segments with checksum fields
> set to all ones (that is, we shouldn't send ~(+0)), but that we had to
> accept either ~(+0) or ~(-0) in received segments.
>
> Strictly speaking, either zero state is completely legal

Not so. Please read RFC1624 sections 3-5.

L.

<L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>

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