Subject: Re: [netmod] ipv6 address representation

From: Seiichi Kawamura <[email-masked]>
Date: Thu, 02 Apr 2009 09:12:49 +0900

Hi Juergen

> So what is your suggestion? Note that the format produced by
> inet_ntop() implementations seems to differ slightly on some
> platforms:

Yes. I confirmed the difference of inet_ntop(), and thank you for
pointing it out. My personal recommendation is, to use ::
and use it to its max, use it in the former in case of a tie-breaker.
That's what we see most oftenly used, and is more human friendly.
But then what do I know. I'm just an operator.

I do know for sure that the "preferred form" as noted on RFC4291 Sec 2.2
item 1 is almost never followed. Nobody wants to count how many zeros
they have to fill in.

But its still just a personal recommendation since I haven't started
a discussion yet on ipv6 WGs.

> What do you plan to do with your document? Has it been discussed
> somewhere at the last IETF? If your plan is to write down how an

I'm already asking the area directors and the chairs if this is
worth discussing, an if so, which WG.
I'll let you know how things turn out.

Thanks
Seiichi

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From: Juergen Schoenwaelder <[email-masked]>
Date: Wed, 15 Apr 2009 11:37:02 +0200

On Tue, Mar 31, 2009 at 04:21:57AM +0200, Seiichi Kawamura wrote:

> From what I've experienced, the "preferred way" noted in RFC4291
> sec 2.2 item 1 is rarely used. BTW, I'm a network
> operator at an ISP/Data Center.

I like to followup on this and nail down what should be in the -03
version of the yang types document. The proposal on the table is to go
back to what we had in an earlier version of the document as the
canonical format for IPv6 addresses:

  The :: substitution must be applied to the longest sequence of
  all-zero 16-bit chunks in an IPv6 address. If there is a tie, the
  first sequence of all-zero 16-bit chunks is replaced by ::. Single
  all-zero 16-bit chunks are not compressed. The normalized format
  uses lower-case characters and leading zeros are not allowed.

This is inline with [1] and with a large fraction of inet_ntop()
implementations. While the proposed format is not the preferred format
spelled out in RFC 4291, it seems to be the most widely deployed
format. Furthermore, operators have given reasons why this is their
preferred format [1].

I personally believe we should adapt the :: compressed format as the
canonical format for IPv6 addresses (and prefixes). But before I make
the edits, I like to see more support for this change from the WG. So
please tell us "I prefer the proposed compressed format" or "I prefer
the uncompressed format".

/js

[1] draft-kawamura-ipv6-text-representation-00.txt

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1, 28759 Bremen, Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>

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From: Martin Bjorklund <[email-masked]>
Date: Wed, 15 Apr 2009 12:13:58 +0200 (CEST)

Hi,

> the uncompressed format".

I prefer the proposed compressed format.

/martin

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From: Ladislav Lhotka <[email-masked]>
Date: Wed, 15 Apr 2009 12:58:28 +0200

> I prefer the proposed compressed format.

Me too.

Lada

> 
> 
> /martin
> _______________________________________________
> netmod mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/netmod
-- 
Ladislav Lhotka, CESNET
PGP Key ID: E74E8C0C

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From: David Kessens <[email-masked]>
Date: Wed, 15 Apr 2009 21:18:57 -0700

Juergen,

>   uses lower-case characters and leading zeros are not allowed.

not speaking as one of the working group chairpeople:

I think this should be fine.

Personally, I would compress a single '0' as well and I usually use
capitals for the hex characters (like in rfc4291).

It would probably be good if some operators would respond with their
preferences.

David Kessens
---

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From: David Partain <[email-masked]>
Date: Thu, 16 Apr 2009 15:33:43 +0200

> I prefer the proposed compressed format.

As non-chair...

+1

David

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From: David Partain <[email-masked]>
Date: Fri, 17 Apr 2009 08:36:43 +0200

> [1] draft-kawamura-ipv6-text-representation-00.txt

Hi all,

So far, no one has said "I prefer the uncompressed format" as far as I can 
see.  Unless someone hollers fast, I personally think we have consensus.

Cheers,

David

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From: Seiichi Kawamura <[email-masked]>
Date: Fri, 24 Apr 2009 11:56:44 +0900

>> [1] draft-kawamura-ipv6-text-representation-00.txt

FYI the draft is now -01.txt
Lots of editorial cleanups.
The core of it has not chaged.
There is also a thread on v6ops about this.

Thanks for all your comments!

Regards
Seiichi