Subject: [Gen-art] Gen-ART review of draft-ietf-6man-text-addr-representation-04

From: <[email-masked]>
Date: Tue, 2 Feb 2010 09:36:41 -0500

I have been selected as the General Area Review Team (Gen-ART) 
reviewer for this draft (for background on Gen-ART, please see 
http://www.alvestrand.no/ietf/gen/art/gen-art-FAQ.html).

Please wait for direction from your document shepherd 
or AD before posting a new version of the draft. 

Document: draft-ietf-6man-text-addr-representation-04
Reviewer: David L. Black
Review Date: February 2, 2010
IESG Telechat date: February 4, 2010

Summary:
This draft is on the right track, but has open issues, described
in the review.

Comments:
The draft provides recommendations for a canonical format for IPv6
addresses.

The open issue is that the draft only provides recommendations, and
does not tightly specify a canonical format.  A tight specification
of a canonical format would include at least one (and preferably
both) of:
	- An algorithm to test whether an IPv6 text address
		is in the canonical format
	- An algorithm to convert an IPv6 text address into canonical
		form.
Code or pseudo-code should be used, and note that the latter item
subsumes the former (a canonicalization algorithm makes no changes to
input that's already in the canonical format).  In the absence of
these elements, I'm not convinced that the draft defines an
interoperable standard that solves the problem.

This document is a good start - I think it's a fine requirements
document that would be appropriate to publish as an Informational RFC,
but I believe that more work is needed to produce a standards-track RFC
that specifies an interoperable representation.  If this document
is published in its current form, it should be edited slightly to
make it clear that it is only a requirements document.

Thanks,
--David
----------------------------------------------------
David L. Black, Distinguished Engineer
EMC Corporation, 176 South St., Hopkinton, MA  01748
+1 (508) 293-7953             FAX: +1 (508) 293-7786
[email-masked]        Mobile: +1 (978) 394-7754
----------------------------------------------------

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From: Brian E Carpenter <[email-masked]>
Date: Wed, 03 Feb 2010 09:26:58 +1300

David,

The problem is that we cannot make this a required format. Like it or
not, there is a range of ways to represent an IPv6 address in text
form, and has been for many years. 2001:DEAD:BEEF:: and 2001:deAd:BEeF::
are the same address.

The draft is very precise on this point:

   The
   recommendation in this document SHOULD be followed by systems when
   generating an address to represent as text, but all implementations
   MUST accept any legitimate [RFC4291] format.

This is the only approach which is consistent with history. Making
that SHOULD into a MUST would be simply unrealistic. But I really
don't understand your objection to this as a standards track document.
It's a complete, if simple, normative specification. (It could also
have been a BCP, imho, but the WG preferred standards track.)

I don't see any particular need to provide pseudocode; it wouldn't
change the normative content. It certainly wouldn't do any harm.

Regards
   Brian Carpenter

On 2010-02-03 03:36, [email-masked] wrote:
> _______________________________________________
> Gen-art mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/gen-art
>

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From: <[email-masked]>
Date: Tue, 2 Feb 2010 16:23:24 -0500

The concern is not whether it is required (MUST) vs. recommended
(SHOULD), but rather than the canonical form is not sufficiently
specified.  Towards that end we disagree on the level of need for
pseudocode.

Thanks,
--David

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
Behalf Of Brian E Carpenter
> Sent: Tuesday, February 02, 2010 3:27 PM
> To: Black, David
> Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked];
> [email-masked]; [email-masked]
> Subject: Re: [Gen-art] Gen-ART reviewof
draft-ietf-6man-text-addr-representation-04

---

From: Brian E Carpenter <[email-masked]>
Date: Wed, 03 Feb 2010 12:03:26 +1300

OK, we do disagree about that ;-)

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From: Seiichi Kawamura <[email-masked]>
Date: Wed, 03 Feb 2010 10:12:33 +0900

> or AD before posting a new version of the draft.

I see the telechat is scheduled for tomorrow.
I will wait.

Regards,
Seiichi