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. Andrews Best Current Practice [Page 1] 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 Andrews Best Current Practice [Page 2] 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 Andrews Best Current Practice [Page 3] RFC 7793 IPv4 Locally-Served DNS Zones Additions May 2016 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 Andrews Best Current Practice [Page 4] RFC 7793 IPv4 Locally-Served DNS Zones Additions May 2016 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, . [RFC6303] Andrews, M., "Locally Served DNS Zones", BCP 163, RFC 6303, DOI 10.17487/RFC6303, July 2011, . [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, . Andrews Best Current Practice [Page 5] RFC 7793 IPv4 Locally-Served DNS Zones Additions May 2016 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 Andrews Best Current Practice [Page 6]