Subject: (ngtrans) I-D ACTION:draft-shin-ngtrans-application-transition-00.txt

From: [email-masked]
Date: Fri, 16 Nov 2001 06:55:30 -0500

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title		: Application Aspects of IPv6 Transition
	Author(s)	: M. Shin et al.
	Filename	: draft-shin-ngtrans-application-transition-00.txt
	Pages		: 12
	Date		: 15-Nov-01
	
The document specifies application aspects of IPv6 transition. As
we deploy IPv6 networks, we should consider IPv6 applications
transition in a host, as well as network transition. This document
clarifies the requirements we have in transition period between
IPv4 applications and IPv6 applications, and also provides
application programmers and/or users with guidelines to use
applications without confusion, when various ngtrans mechanisms are
applied.  This document does not try to define any new protocol.
The proposals contained in this document are based on the work of
the Ngtrans working group.

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---

From: Pekka Savola <[email-masked]>
Date: Fri, 16 Nov 2001 23:20:39 +0200 (EET)

> the Ngtrans working group.

This does not discuss the mess with network daemons and such in the
multiprotocol environment.  That is, should one only use AF_INET6 and let
IPv4 users connect using mapped addresses or what?

.. too bad there isn't much of a consensus on this subject, I think ..

Also, there's much more to it to 4.3 than using getaddrinfo for getting
the names..  That is, using sockaddr_storage and friends because you
cannot know how much space you have to allocate for the addresses,
sockaddr_in or sockaddr_in6.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords

---

From: "Jeroen Massar" <[email-masked]>
Date: Sat, 17 Nov 2001 01:14:48 +0100

Pekka Savola <[email-masked]> wrote:

> > 	Filename	            :
draft-shin-ngtrans-application-transition-00.txt
> > 	Date		: 15-Nov-01
<SNIP>

> sockaddr_in or sockaddr_in6.

That's where "Implementing AF-independent application" (
http://www.kame.net/newsletter/19980604/ ) by Itojun comes into play.
Maybe this draft could refer to it for a more extensive explanation ?
Also, it will be a good thing(tm) IMHO to hint developers to not code
their applications just for IPv6 but for AF independence,
just in case we do ever get IPv42 or something; our great-great-great
grand children will thank us for that. ;)

Greets,
 Jeroen

---

From: Myung-Ki Shin <[email-masked]>
Date: Sat, 17 Nov 2001 09:41:05 +0900

> IPv4 users connect using mapped addresses or what?

    The scope of our draft is to provide guidelines for
    application transition (IPv4 -> IPv6) under Ngtrans mechanisms.

    I think  'the mess with network daemons and such in the
    multiprotocol environment'  is another issue.

> .. too bad there isn't much of a consensus on this subject, I think ..

    I think IPv6 application transition is indedendent on IPv6 network transiton.
   (that is, even if network transiton mechanisms are fully
     deployed, we still have problems occured in transition period
     between IPv4 applications and IPv6 applications.
    We describe these requirements in section 3.)

   So, I think it is time to discuss application transition issues in the viewpoint
of
   appication programmers and/or users who will face IPv6 transition.

   This draft will be able to be useful guidelines for them.

> sockaddr_in or sockaddr_in6.

   You're right, we knew that, but the reason why we didn't mention
"sockaddr_storage" is
   that's out of our subject.

    Thanks,
    Myung-Ki.

---

From: Pekka Savola <[email-masked]>
Date: Sat, 17 Nov 2001 09:23:26 +0200 (EET)

>     multiprotocol environment'  is another issue.

Perhaps 'application' would have to defined more explicitly then.  It can 
mean all programs run on a node, including server applications.

>    that's out of our subject.

Well, I'm not sure about the subject then; is it not an application 
writer's problem to code an IPv4/IPv6 compatible code?  You already showed 
how to use getaddrinfo properly.  The application writer has now to also 
deal with the results of getaddrinfo; certain changes to the code are 
required.

IMO, perhaps getaddrinfo etc. should be moved to an appendix and tagged 
with a disclaimer like "there are also several other issues when dealing 
with IPv4/IPv6 capable software: ..., ..., ..." or expanded a bit possibly 
like above.