Internet Engineering Task Force (IETF)                        M. Andrews
Request for Comments: 7793                                           ISC
BCP: 163                                                        May 2016
Category: Best Current Practice
ISSN: 2070-1721

                  Adding 100.64.0.0/10 Prefixes to the
                 IPv4 Locally-Served DNS Zones Registry

Abstract

   RFC 6598 specifies that "Reverse DNS queries for Shared Address Space
   addresses [100.64.0.0/10] MUST NOT be forwarded to the global DNS
   infrastructure."

   This document formally directs IANA to add the associated zones to
   the "IPv4 Locally-Served DNS Zones Registry" to prevent such queries
   from accidentally leaking to the global DNS infrastructure.

Status of This Memo

   This memo documents an Internet Best Current Practice.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   BCPs is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7793.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

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RFC 7793         IPv4 Locally-Served DNS Zones Additions        May 2016

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Changes to the IPv4 Locally-Served DNS Zones Registry . . . .   2
     2.1.  RFC 6598 Zones  . . . . . . . . . . . . . . . . . . . . .   2
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   5.  Normative References  . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   6
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   [RFC6598] specifies that "Reverse DNS queries for Shared Address
   Space addresses [100.64.0.0/10] MUST NOT be forwarded to the global
   DNS infrastructure."  [RFC6303] provides guidance on handling such
   queries.

   This document directs the IANA to add the IPv4 reverse zones
   corresponding to 100.64.0.0/10, a netblock reserved in [RFC6598], to
   the "IPv4 Locally-Served DNS Zone Registry" established in [RFC6303].

   Unlike the addresses described in [RFC1918], which are not expected
   to be seen by other parties, the addresses defined by [RFC6598] are
   expected to be seen by parties other than those deploying the
   addresses.  Therefore, it is more crucial that recursive nameservers
   default to serving these zones locally.

2.  Changes to the IPv4 Locally-Served DNS Zones Registry

   IANA has added the zones listed in "RFC 6598 Zones" (Section 2.1) to
   the "IPv4 Locally-Served DNS Zone Registry".

2.1.  RFC 6598 Zones

      64.100.IN-ADDR.ARPA

      65.100.IN-ADDR.ARPA

      66.100.IN-ADDR.ARPA

      67.100.IN-ADDR.ARPA

      68.100.IN-ADDR.ARPA

      69.100.IN-ADDR.ARPA

      70.100.IN-ADDR.ARPA

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RFC 7793         IPv4 Locally-Served DNS Zones Additions        May 2016

      71.100.IN-ADDR.ARPA

      72.100.IN-ADDR.ARPA

      73.100.IN-ADDR.ARPA

      74.100.IN-ADDR.ARPA

      75.100.IN-ADDR.ARPA

      76.100.IN-ADDR.ARPA

      77.100.IN-ADDR.ARPA

      78.100.IN-ADDR.ARPA

      79.100.IN-ADDR.ARPA

      80.100.IN-ADDR.ARPA

      81.100.IN-ADDR.ARPA

      82.100.IN-ADDR.ARPA

      83.100.IN-ADDR.ARPA

      84.100.IN-ADDR.ARPA

      85.100.IN-ADDR.ARPA

      86.100.IN-ADDR.ARPA

      87.100.IN-ADDR.ARPA

      88.100.IN-ADDR.ARPA

      89.100.IN-ADDR.ARPA

      90.100.IN-ADDR.ARPA

      91.100.IN-ADDR.ARPA

      92.100.IN-ADDR.ARPA

      93.100.IN-ADDR.ARPA

      94.100.IN-ADDR.ARPA

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      95.100.IN-ADDR.ARPA

      96.100.IN-ADDR.ARPA

      97.100.IN-ADDR.ARPA

      98.100.IN-ADDR.ARPA

      99.100.IN-ADDR.ARPA

      100.100.IN-ADDR.ARPA

      101.100.IN-ADDR.ARPA

      102.100.IN-ADDR.ARPA

      103.100.IN-ADDR.ARPA

      104.100.IN-ADDR.ARPA

      105.100.IN-ADDR.ARPA

      106.100.IN-ADDR.ARPA

      107.100.IN-ADDR.ARPA

      108.100.IN-ADDR.ARPA

      109.100.IN-ADDR.ARPA

      110.100.IN-ADDR.ARPA

      111.100.IN-ADDR.ARPA

      112.100.IN-ADDR.ARPA

      113.100.IN-ADDR.ARPA

      114.100.IN-ADDR.ARPA

      115.100.IN-ADDR.ARPA

      116.100.IN-ADDR.ARPA

      117.100.IN-ADDR.ARPA

      118.100.IN-ADDR.ARPA

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      119.100.IN-ADDR.ARPA

      120.100.IN-ADDR.ARPA

      121.100.IN-ADDR.ARPA

      122.100.IN-ADDR.ARPA

      123.100.IN-ADDR.ARPA

      124.100.IN-ADDR.ARPA

      125.100.IN-ADDR.ARPA

      126.100.IN-ADDR.ARPA

      127.100.IN-ADDR.ARPA

3.  IANA Considerations

   Per this document, IANA has added the zones listed in "RFC 6598
   Zones" (Section 2.1) to the "IPv4 Locally-Served DNS Zone Registry".

   IANA is reminded that an insecure delegation for these zones is
   required for compliance with [RFC6303] to break the DNSSEC chain of
   trust.

4.  Security Considerations

   This document does not present additional security risks to the
   Internet than those described in [RFC6303] and [RFC6598].

5.  Normative References

   [RFC1918]  Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,
              and E. Lear, "Address Allocation for Private Internets",
              BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996,
              <http://www.rfc-editor.org/info/rfc1918>.

   [RFC6303]  Andrews, M., "Locally Served DNS Zones", BCP 163,
              RFC 6303, DOI 10.17487/RFC6303, July 2011,
              <http://www.rfc-editor.org/info/rfc6303>.

   [RFC6598]  Weil, J., Kuarsingh, V., Donley, C., Liljenstolpe, C., and
              M. Azinger, "IANA-Reserved IPv4 Prefix for Shared Address
              Space", BCP 153, RFC 6598, DOI 10.17487/RFC6598, April
              2012, <http://www.rfc-editor.org/info/rfc6598>.

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Acknowledgements

   The author would like to thank Joe Abley for his review comments.

Author's Address

   M. Andrews
   Internet Systems Consortium
   950 Charter Street
   Redwood City, CA  94063
   United States

   Email: marka@isc.org

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