Subject: RE: draft-olson-sdp-ipv6-02.txt

From: "Hesham Soliman (EPA)" <[email-masked]>
Date: Tue, 16 Oct 2001 12:22:06 +1000

> Should the draft say anything about the use of IPv6-mapped-IPv4 addresses?
> The BNF makes them legal syntactically, but I'm not sure the semantics are
> clear (it should, at least, note the potential for representing an IPv4
> address in two different ways).
> 
	=> Excellet point. I read the draft a long time ago so I have to
	refresh my memory, but I believe if we're adding this some 
	behavioural deails are needed for end hosts and/or proxy
	servers to know how to handle these addresses. 

	Hesham

---

From: Bill Manning <[email-masked]>
Date: Tue, 16 Oct 2001 09:22:47 -0700 (PDT)

% > Should the draft say anything about the use of IPv6-mapped-IPv4 addresses?
% > The BNF makes them legal syntactically, but I'm not sure the semantics are
% > clear (it should, at least, note the potential for representing an IPv4
% > address in two different ways).
% > 
% 	=> Excellet point. I read the draft a long time ago so I have to
% 	refresh my memory, but I believe if we're adding this some 
% 	behavioural deails are needed for end hosts and/or proxy
% 	servers to know how to handle these addresses. 
% 
% 	Hesham

That may not be enough....  I thought about send in this as an ID, based on
experiences w/ the DNS.
	----------------------------------------------
Internet Draft                                              Bill Manning 
draft-bmanning-mapcon-01.txt                                         ISI
Expires March 2002                                        September 2001

          	Mapped IPv4 address Considerations in the DNS
 
Status of this Memo

   This draft, file name draft-bmanning-mapcon-01.txt, is intended to become
   something that might be of use to those who are interested in the
   operational requirements of an IP based network.  It does not specify
   an Internet standard of any kind. Distribution of this document is 
   unlimited. Comments should be sent to the author.

   This document is an Internet-Draft and is NOT offered in accordance with 
   Section 10 of RFC2026, and the author does not provide the IETF with any 
   rights other than to publish as an Internet-Draft.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

1 Abstract

   This document makes an observation that might really be a  Best 
   Current Practice for the Internet Community.

   The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC 2119].

2. Recommendation

   Due to ambiguities in the specifications for operating systems and
   IP stacks use of the construct known as a IPv6 mapped IPv4 address,
   it is apparent that a prudent DNS administrator will NEVER add
   a mapped IPv4 address into ANY zone file, even though most current
   DNS server implementations will allow it.

3. Security Considerations

   This document is not known to create new security issues and may close
   some from an operating systems perspective. One may reference earlier
   work done by itojun at the following URL:
   http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-01.txt

4. IANA Considerations

   No IANA actions are required by this document.

5. Acknowledgments

   In no particular order, Akira Kato, Mark Andrews, Bruce Campbell, 
   Andreas Gustafsson, Jun-ichiro itojun Hagino, Daniel Karrenberg,
   Jun Murai, and George Michaelson. Further discussion was held on
   the dnsops WG mailing list <[email-masked]> in September 2001.
   I appreciate the use of the WG mailing list for this off-charter
   observation and associated discussion.

   At the time this document was originated, funding for the RFC Editor 
   function was provided by the Internet Society.

6. Author's Address

	Bill Manning
        USC/ISI
        4676 Admiralty Way, #1001
        Marina del Rey, CA. 90292
        USA
        [email-masked]
        310.822.1511      

--bill