Subject: [BEHAVE] Translating ICMPv4 error messages

From: Dave Thaler <[email-masked]>
Date: Thu, 31 Dec 2009 20:54:49 +0000

Draft-ietf-behave-v6v4-xlate-05 section 2.4 states:
> The translation of the inner IP header can be done by recursively
> invoking the function that translated the outer IP headers.

The embedded transport-layer header needs to be translated too, 
if the address translation is not checksum neutral, correct?
Currently this section only mentions IP headers.

Assuming so, there's one case that deserves special mention: 
if you get an ICMPv4 error that embeds an ICMPv4 error that 
embeds an ICMPv4 error that... (etc until MTU is reached), 
do you have to keep traversing the entire packet and do all 
the translations?  I would hope not, but "recursively
invoking" sure sounds like it.

-Dave