Re: [tcpm] ICMP error origination timeliness

Joe Touch <touch@ISI.EDU> Mon, 07 April 2008 13:34 UTC

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Date: Mon, 07 Apr 2008 06:33:57 -0700
From: Joe Touch <touch@ISI.EDU>
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To: "Anantha Ramaiah (ananth)" <ananth@cisco.com>
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Cc: tcpm@ietf.org, Fernando Gont <fernando@gont.com.ar>
Subject: Re: [tcpm] ICMP error origination timeliness
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Anantha Ramaiah (ananth) wrote:
...
> In a nutshell, the benefits of adding robustness by dropping the
> suspicious ICMP messages far outwiegh the corner cases (which I am still
> not convinced that those are real) where we don't process an "outdated"
> ICMP message.

The bulk of the benefits of robustness are afforded by having ICMPs 
depend on the state and progress of the connection.

We have got to get away from this notion, BTW, that 'unexpected messages 
imply an attack'. The only thing such messages indicate is the inability 
of the programmer to see a valid corner case.

Joe

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