Re: Review of draft-ietf-6man-rfc4291bis-06

Suresh Krishnan <> Fri, 13 January 2017 03:56 UTC

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From: Suresh Krishnan <>
Date: Thu, 12 Jan 2017 22:55:59 -0500
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Subject: Re: Review of draft-ietf-6man-rfc4291bis-06
To: Randy Bush <>
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Hi Randy,

On Thu, Jan 12, 2017 at 7:49 PM, Randy Bush <> wrote:
>>> to be clear, i have no problem with iids being 64-bit.  my issue is with
>>> unicast globals being classful in 2.4.4.
>> Randy I take your point, but this supposed conflict isn't new, it's not
>> introduced in 4291bis, it goes back to RFC3513.
> i know; and i have pushed back every cm of the way.  it took years to
> get the other classful insanity, tls/nla, removed.  the old cidr war
> continues.  this last bit of classfulness (excuse the word) too will
> pass.
>> Do you have a suggestion how to change this within the context of
>> advancing this to Internet Standard?
> yes.  simply remove the mandatory requirement for classful global
> unicast addresses.

I do see your point but I do not feel it is equivalent to classful
addressing in IPv4. i.e. Looking at the leading X bits does not
directly determine the IID length.

That said, I would like to understand better your exact concern with
the text in 2.4.4. What exactly would you like to change (is it the
m-bit verbiage)? Can you come up with a text change proposal so that
we can discuss it in the 6man WG?


P.S.: The document is not in IETF Last Call yet. It has completed WGLC
and is in AD evaluation. Brian did his INT Dir review for the INT ADs.
The IETF Last Call will start soon.