Re: A 3rd try at a proposal for draft-ietf-6man-rfc4291bis-07

Lorenzo Colitti <> Tue, 07 March 2017 03:19 UTC

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From: Lorenzo Colitti <>
Date: Tue, 7 Mar 2017 12:18:41 +0900
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Subject: Re: A 3rd try at a proposal for draft-ietf-6man-rfc4291bis-07
To: David Farmer <>
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On Tue, Mar 7, 2017 at 4:05 AM, David Farmer <> wrote:
> Instead, I would suggest another approach: see what the problems with 4291
>> are, *write them down*, and only then write a document explaining what
>> should be changed and why.
> The list of 7 points are the problems that many see with 4291bis, maybe
> overly summarized, but they are there.

Well, but what you provided is an alternative solution, not a problem
statement. Example of a problem statement would be, "RFC 4291 does not
allow non-64-bit IID lengths. However, assigning smaller prefix lengths is
necessary because [...]".

I can't help fill in the [...] because I personally don't see what you can
do with a /113 that you can't do with a /64 (other than conserve addresses,
which has always been a non-goal), but there seem to be several
participants who do see a problem. What I'm saying is that if we want to
change the standard, the people who see a problem with it should articulate
that problem in a way that it's possible to find a solution using informed
and documented engineering trade-offs rather than opinions.