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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      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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