idnits 2.17.1 draft-cheshire-sudn-ipv4only-dot-arpa-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The abstract seems to contain references ([RFC6761], [RFC7050]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. == There are 3 instances of lines with non-RFC6890-compliant IPv4 addresses in the document. If these are example addresses, they should be changed. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 28, 2016) is 3001 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group S. Cheshire 3 Internet-Draft D. Schinazi 4 Updates: 7050 (if approved) Apple Inc. 5 Intended status: Standards Track January 28, 2016 6 Expires: July 31, 2016 8 Special Use Domain Name 'ipv4only.arpa' 9 draft-cheshire-sudn-ipv4only-dot-arpa-00 11 Abstract 13 The document "Discovery of the IPv6 Prefix Used for IPv6 Address 14 Synthesis" [RFC7050] specifies the Special Use Domain Name 15 'ipv4only.arpa', with certain precise special properties, but 16 neglected to include a Domain Name Reservation Considerations section 17 [RFC6761] formalizing those special properties. This document 18 updates RFC 7050 and formally specifies the Special Use Domain Name 19 rules for ipv4only.arpa. 21 Status of this Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at http://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on July 31, 2016. 38 Copyright Notice 40 Copyright (c) 2016 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (http://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 1. Introduction 55 The document "Discovery of the IPv6 Prefix Used for IPv6 Address 56 Synthesis" [RFC7050] specifies the Special Use Domain Name 57 'ipv4only.arpa', with certain precise special properties, but 58 neglected to include a Domain Name Reservation Considerations section 59 [RFC6761] formally stating those special properties. 61 As a result of the name 'ipv4only.arpa' not being formally declared 62 to have special properties, there was no mandate for software to 63 treat this name specially. Queries for this name are handled 64 normally, and result in queries to the 'arpa' name servers. At 65 times, for reasons that are as yet unclear, the 'arpa' name servers 66 have been observed to be slow or unresponsive. The failures of these 67 'ipv4only.arpa' queries result in failures of software that depends 68 on them for NAT64 address synthesis. Also, having millions of 69 devices around the world depend on these answers generates pointless 70 additional load on the 'arpa' name servers, which is completely 71 unnecessary when this name is defined, by Internet Standard, to have 72 only two address records, 192.0.0.170 and 192.0.0.171, and no other 73 records. 75 To remedy this situation, this document updates RFC 7050 and 76 specifies the formal Special Use Domain Name rules for ipv4only.arpa. 78 2. Conventions and Terminology Used in this Document 80 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 81 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 82 "OPTIONAL" in this document are to be interpreted as described in 83 "Key words for use in RFCs to Indicate Requirement Levels" [RFC2119]. 85 3. Security Considerations 87 Hard-coding the answers for ipv4only.arpa queries avoids the risk of 88 malicious devices intercepting those queries and returning incorrect 89 answers. 91 4. IANA Considerations 93 [Once published, this should say] IANA has recorded the name 94 'ipv4only.arpa' in the Special-Use Domain Names registry [SUDN]. 96 4.1. Domain Name Reservation Considerations 98 The name 'ipv4only.arpa' is special [RFC6761] in the following ways: 100 1. Users should never have reason to encounter the ipv4only.arpa 101 domain nanme. If they do, queries for ipv4only.arpa should 102 result in the answers specified in RFC 7050. Users have no need 103 to know that ipv4only.arpa is special. 105 2. Application software may explicitly use the name ipv4only.arpa 106 for NAT64 address synthesis, and expect to get the answers 107 specified in RFC 7050. If application software encounters the 108 name ipv4only.arpa as user input, the application software should 109 resolve that name as usual and need not treat it in any special 110 way. 112 3. Name resolution APIs and libraries SHOULD NOT recognize 113 ipv4only.arpa as special and SHOULD NOT treat it differently. 114 Name resolution APIs SHOULD send queries for this name to their 115 configured recursive/caching DNS server(s). 117 4. Recursive/caching DNS servers SHOULD recognize ipv4only.arpa as 118 special and SHOULD NOT, by default, attempt to look up NS records 119 for it, or otherwise query authoritative DNS servers in an 120 attempt to resolve this name. Instead, recursive/caching DNS 121 servers SHOULD, by default, act as authoritative and generate 122 immediate responses for all such queries. Traditional recursive/ 123 caching DNS servers that act as authoritative for this name MUST 124 generate only the 192.0.0.170 and 192.0.0.171 responses for these 125 queries, and no others. DNS64 recursive/caching DNS servers MUST 126 generate the 192.0.0.170 and 192.0.0.171 address record responses 127 for these queries, and MUST generate the appropriate synthesized 128 IPv6 address record responses for all AAAA queries. This is to 129 avoid unnecessary load on the 'arpa' name servers. 131 5. Traditional authoritative DNS servers SHOULD recognize 132 ipv4only.arpa as special and SHOULD, by default, generate 133 immediate negative responses for all such queries, unless 134 explicitly configured otherwise by the administrator (which only 135 applies to the administrators of the 'arpa' namespace). 137 6. DNS server operators MUST understand that ipv4only.arpa is a 138 special name, with answers specified by Internet Standard. 140 7. DNS Registries/Registrars MUST understand that ipv4only.arpa is a 141 special name, with answers specified by Internet Standard. 143 5. References 145 5.1. Normative References 147 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 148 Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ 149 RFC2119, March 1997, 150 . 152 [RFC6761] Cheshire, S. and M. Krochmal, "Special-Use Domain Names", 153 RFC 6761, DOI 10.17487/RFC6761, February 2013, 154 . 156 [RFC7050] Savolainen, T., Korhonen, J., and D. Wing, "Discovery of 157 the IPv6 Prefix Used for IPv6 Address Synthesis", 158 RFC 7050, DOI 10.17487/RFC7050, November 2013, 159 . 161 5.2. Informative References 163 [SUDN] "Special-Use Domain Names Registry", . 166 Authors' Addresses 168 Stuart Cheshire 169 Apple Inc. 170 1 Infinite Loop 171 Cupertino, California 95014 172 USA 174 Phone: +1 408 974 3207 175 Email: cheshire@apple.com 176 David Schinazi 177 Apple Inc. 178 1 Infinite Loop 179 Cupertino, California 95014 180 USA 182 Phone: +1 669 227 9921 183 Email: dschinazi@apple.com