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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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: [email protected]






































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