RFC 3152

Okay bestie, this one is a Best Current Practice 🎀 (BCP 49, so it's the official "do this" list for the whole Internet community) and it's all about giving IPv6 addresses their own reverse-lookup home ✨. It came out in August 2001 from R. Bush at RGnet 💖. It updates RFCs 2874, 2772, 2766, 2553 and 1886, so those older docs get a little glow-up from this one 🦋.

Status of this Memo 📝

This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited.

Copyright Notice 🌈

Copyright (C) The Internet Society (2001). All Rights Reserved.

Abstract 🌸

This doc talks about why we need to delegate the IP6.ARPA DNS zone, and lays out a plan for how it's run technically 🧚.

1. Why IP6.ARPA? 💅

Okay so, IPv6 addresses need "reverse mapping" (going from an address back to a DNS name) just like IPv4 already has with IN-ADDR.ARPA 🔥. It's giving déjà vu, but make it bigger 😭.

The IAB suggested using the ARPA top level domain for infrastructure subdomains whenever it makes sense. (Fun fact: the name is now treated as an acronym for "Address and Routing Parameters Area" 🤓.) ARPA is already doing the job for IPv4 reverse mapping, and it's also where E.164 numbering lives on the Internet [RFC2916 RFC3026] 💜.

IETF consensus landed on using IP6.ARPA for address-to-name mapping in the IPv6 address space [RFC2874] 👑. Literally everyone agreed, iykyk 🙈.

2. Obsoleted Usage 🥀

This document deprecates the old IP6.INT references in [RFC1886] section 2.5, [RFC2553] section 6.2.3, [RFC2766] section 4.1, [RFC2772] section 7.1.c, and [RFC2874] section 2.5 🫶.

Here, "deprecate" just means the old way isn't appropriate for new implementations, and IP6.INT will probably get phased out in an orderly way 🍓. No drama, just a gentle goodbye 🕊️.

3. IANA Considerations 🎀

This memo asks IANA to delegate the IP6.ARPA domain, following instructions that the IAB will provide ✨. Names inside this zone then get delegated to the regional IP registries, matching how IPv6 address space is already handed out to them 💖. The names should be hierarchic to match the address space assignment 🧚.

4. Security Considerations 🔒

Okay, real talk: DNS spoofing of address-to-name mapping has been exploited in IPv4 💀. But delegating the IP6.ARPA zone creates no new threats to the security of the Internet 🛡️. Slay 💅.

5. References 📚

[RFC1886]   Thomson, S. and C. Huitema, "DNS Extensions to support IP
            version 6", RFC 1886, December 1995.

[RFC2553]   Gilligan, R., Thomson, S., Bound, J. and W. Stevens,
            "Basic Socket Interface Extensions for IPv6", RFC 2553,
            March 1999.

[RFC2766]   Tsirtsis, G. and P. Srisuresh, "Network Address
            Translation - Protocol Translation (NAT-PT)", RFC 2766,
            February 2000.

[RFC2772]   Rockell, R. and R. Fink, "6Bone Backbone Routing
            Guidelines", RFC 2772, February 2000.

[RFC2874]   Crawford, M. and C. Huitema, "DNS Extensions to Support
            IPv6 Address Aggregation and Renumbering", RFC 2874, July
            2001.

[RFC2916]   Faltstrom, P., "E.164 number and DNS", RFC 2916,
            September 2000.

[RFC3026]   Blane, R., "Liaison to IETF/ISOC on ENUM", RFC 3026,
            January 2001.

6. Author's Address 📮

Randy Bush
5147 Crystal Springs
Bainbridge Island, WA US-98110

Phone: +1 206 780 0431
EMail: randy@psg.com

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Full Copyright Statement 🌟

Copyright (C) The Internet Society (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 or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE 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.

Acknowledgement 💜

Funding for the RFC Editor function is currently provided by the Internet Society ✨.