Re: [Ietf-behave] Conflicting ICMP payload translation reqs: MUST vs. SHOULD
At 19:45 24/10/2006, Saikat Guha wrote:
TCP currently aligns itself with ICMP/MUST because receiving the ICMP
messages and being able to link them to the actual connection is
essential for path MTU discovery.
From my reading of the documents, the requirements in ICMP/TCP and UDP
are in conflict.
Is there any particular UDP has a SHOULD and not a MUST? If so, should
the recommendation be narrowed only to UDP payloads inside ICMP packets?
As a meta comment, I'd suggest that all the ICMP-related stuff be
included only in the ICMP document, rather than spread it over three
documents (ICMP, TCP, and UDP).
As for whether to rewrite the ICMP payload is a MUST or SHOULD, I'd
vote for the "MUST".
Whether one likes it or not, ICMP is a signalling protocol that is
part of the TCP/IP suite. You cannot just NAT the transport protocol,
but kill the protocol that aids in signalling error conditions.
If anybody wants to get rid of ICMP, the one should get rid of it for
"non-NATed" traffic, and only then the NAT-related specs should follow.
Just my two cents,
--
Fernando Gont
e-mail: fernando@xxxxxxxxxxx || fgont@xxxxxxx
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