Internet Draft Bill Manning draft-bmanning-mapcon-00.txt ISI Expires April 2002 28 Oct 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 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 bmanning@isi.edu 310.822.1511 7. Full Copyright Statement Copyright (C) Bill Manning (2001). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice. The limited permissions granted above are perpetual and will not be revoked by Bill Manning or his successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.