Subject: IPv6 Capable and IPv6 ONLY for Scenarios

From: "Bound, Jim" <[email-masked]>
Date: Fri, 24 Oct 2003 00:35:23 -0400

Folks,

Want to do logic check here for IPv6 ONLY.

IPv6 capable does not imply or preclude IPv6 ONLY.  Does anyone
disagree?

IPv6 ONLY should only mean a node that has NO IPv4 stack to process IPv4
packets?

To reference a network that is IPv6 capable can imply IPv4 is possible
but not used or use is limited.  Or IPv6 is not turned on or IPv6 is
limited.

Any objecttions to these assumptions or can others add useful
clarifiations.

thanks
/jim

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From: "Christian Strauf (JOIN)" <[email-masked]>
Date: Fri, 24 Oct 2003 09:55:59 +0200

Hi Jim

> IPv6 capable does not imply or preclude IPv6 ONLY.  Does anyone
This is the way it should be ideally. I've seen cases though where an
IPv6 capable OS and also IPv6 capable applications do not work in IPv6
only environments.

> IPv6 ONLY should only mean a node that has NO IPv4 stack to process IPv4
My impression is that in a lot of cases it makes sense to clearly
differentiate between IPv6 only stack and IPv6 only connectivity
(sometimes you can see people talking about IPv6 only hosts where the
hosts are dual-stacked but have IPv6 only connectivity) because pinning
IPv6 to either the stack or the connectivity can be ambiguous. In some
transition scenarios it makes quite a difference if you have a
dual-stack host with an IPv6 only connection or a IPv6 only stack host
with an IPv6 only connection.

> but not used or use is limited.  Or IPv6 is not turned on or IPv6 is
At the moment my understanding is that the last case (IPv6 is limited)
is meant when talking about an IPv6 capable network and only the number
of limitations varies from network to network. If IPv4 and IPv6 is
equally well supported ("fully IPv6 capable network"), one would rather
talk about dual-stack networks, wouldn't one? Just my 2-€-cents.

Christian
-- 
JOIN - IP Version 6 in the WiN  Christian Strauf
A DFN project                   Westfälische Wilhelms-Universität Münster
http://www.join.uni-muenster.de Zentrum für Informationsverarbeitung
Team: [email-masked]      Röntgenstrasse 9-13
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From: [email-masked]
Date: Fri, 24 Oct 2003 01:12:21 -0700 (PDT)

> IPv6 ONLY should only mean a node that has NO IPv4 stack to process IPv4

	one could make the argument that this is a correct statement
	but it may be overly restrictive. practically, there is no distinction
	between "no ipv4 stack" and "no interface w/ ipv4 enabled"

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From: Pekka Savola <[email-masked]>
Date: Fri, 24 Oct 2003 11:15:24 +0300 (EEST)

On Fri, 24 Oct 2003, Christian Strauf (JOIN) wrote:
> differentiate between IPv6 only stack and IPv6 only connectivity [...]

Agreed -- there is a potential for confusion here.  I'm not sure whether 
it makes sense to try to define and ratify exact semantics here, but at 
least the terminology used should be made clear.

(pretty much agree with other points as well -- I also think that
"dual-stack network" is closer, and in a way more honest way or saying
that the network is mostly (or fully) IPv6 capable)

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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From: Tim Chown <[email-masked]>
Date: Fri, 24 Oct 2003 10:45:58 +0100

> least the terminology used should be made clear.

I think that there are many "IPv6 only" testbeds running Linux, BSD etc
where you only configure IPv6, and only use IPv6 connectivity, despite
IPv4 being present but not enabled.

So what Pekka says is fine by me "dual stack with only IPv6 enabled" (or
perhaps more accurately "hybrid stack").

While innovative new, really IPv6 only devices may emerge soon, there's 
little chance we'll see, for example, "Windows v6" without any IPv4 support
for a long, long time.   The question is really what is enabled for comms
and what the apps actually use.

It would be nice to have common agreed language to use in all v6ops (and
wider) IETF docs.

Tim

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From: "Robson Oliveira" <[email-masked]>
Date: Fri, 24 Oct 2003 11:48:31 -0200

Tim,

For sure "Windows v6" without any IPv4 support for a long, long time, but we
could manager the DNS to answer only v6 to conclude our objectives: "IPv6
only connectivity".

Robson

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Tim Chown
Sent: Friday, October 24, 2003 7:46 AM
To: [email-masked]
Subject: Re: IPv6 Capable and IPv6 ONLY for Scenarios

Tim