idnits 2.17.1 draft-anderson-v6ops-v4v6-xlat-prefix-02.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 : ---------------------------------------------------------------------------- == There are 18 instances of lines with non-RFC3849-compliant IPv6 addresses in the document. If these are example addresses, they should be changed. 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Anderson 3 Internet-Draft Redpill Linpro 4 Updates: 6890 (if approved) September 9, 2016 5 Intended status: Standards Track 6 Expires: March 13, 2017 8 Local-use IPv4/IPv6 Translation Prefix 9 draft-anderson-v6ops-v4v6-xlat-prefix-02 11 Abstract 13 This document reserves the IPv6 prefix 64:ff9b:1::/48 for local use 14 with IPv4/IPv6 translation mechanisms. It updates RFC6890 in order 15 to reflect this reservation. 17 Status of This Memo 19 This Internet-Draft is submitted in full conformance with the 20 provisions of BCP 78 and BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF). Note that other groups may also distribute 24 working documents as Internet-Drafts. The list of current Internet- 25 Drafts is at http://datatracker.ietf.org/drafts/current/. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 This Internet-Draft will expire on March 13, 2017. 34 Copyright Notice 36 Copyright (c) 2016 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (http://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 52 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 53 3. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 2 54 4. Choosing 64:ff9b:1::/48 . . . . . . . . . . . . . . . . . . . 3 55 5. Deployment Considerations . . . . . . . . . . . . . . . . . . 3 56 6. Checksum Neutrality . . . . . . . . . . . . . . . . . . . . . 4 57 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 58 8. Security Considerations . . . . . . . . . . . . . . . . . . . 5 59 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 60 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 61 9.2. Informative References . . . . . . . . . . . . . . . . . 5 62 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6 63 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 65 1. Introduction 67 This document reserves 64:ff9b:1::/48 for local use with IPv4/IPv6 68 translation mechanisms. This facilitates the co-existence of 69 multiple IPv4/IPv6 translation mechanisms in the same network without 70 requiring the use of a Network-Specific Prefix assigned from the 71 operator's allocated global unicast address space. 73 2. Terminology 75 This document makes use of the following terms: 77 Network-Specific Prefix (NSP) 78 A globally unique prefix assigned by a network operator for use 79 with and IPv4/IPv6 translation mechanism, cf. [RFC6052] 81 Well-Known Prefix (WKP) 82 The prefix 64:ff9b::/96, which is reserved for use with the 83 [RFC6052] IPv4/IPv6 address translation algorithm. 85 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 86 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 87 document are to be interpreted as described in [RFC2119]. 89 3. Problem Statement 91 Since the WKP 64:ff9b::/96 was reserved by [RFC6052], several new 92 IPv4/IPv6 translation mechanisms have been defined by the IETF. 93 These target various different use cases. An operator might 94 therefore wish to make use of several of them simultaneously. 96 The smallest possible prefix supported by the [RFC6052] algorithm is 97 a /96. Because the WKP is a /96, an operator preferring to use a WKP 98 over an NSP can only do so for only one of his IPv4/IPv6 translation 99 mechanisms. All others must necessarily use an NSP. 101 The WKP is reserved specifically for use with the algorithm specified 102 in [RFC6052]. More recent IETF documents describe IPv4/IPv6 103 translation mechanisms that use different algorithms. An operator 104 deploying such mechanisms can not make use of the WKP in a legitimate 105 fashion. 107 Section 3.1 of [RFC6052] imposes certain restrictions on the use of 108 the WKP. These restrictions might conflict with the operator's 109 desired use of an IPv4/IPv6 translation mechanism. 111 In summary, there is a need for a prefix that facilitates the co- 112 existence of multiple IPv4/IPv6 translation mechanisms (that do not 113 necessarily use the [RFC6052] algorithm). 115 4. Choosing 64:ff9b:1::/48 117 The primary reason for choosing 64:ff9b:1::/48 is that it is adjacent 118 to the [RFC6052] WKP 64:ff9b::/96. As these two prefixes are 119 intended for very similar uses, it is prudent to allow them to be 120 referred to using a single aggregate (64:ff9b::/47). 122 The prefix length of 48 bits was chosen in order to attain the goal 123 of facilitating multiple simultaneous deployments of IPv4/IPv6 124 translation in a single network. The shortest IPv4/IPv6 translation 125 prefixes reported to the V6OPS working group as being used in 126 production was 64 bits. 64:ff9b:1::/48 will accommodate up to 65536 127 such prefixes. 129 While the [RFC6052] algorithm specifies IPv4/IPv6 translation 130 prefixes as short as /32, facilitating for multiple instances of 131 these was considered as too wasteful by the V6OPS working group. 133 5. Deployment Considerations 135 64:ff9b:1::/48 is intended as a technology-agnostic and generic 136 reservation. A network operator may freely use it in combination 137 with any kind of IPv4/IPv6 translation mechanism deployed within his 138 network. 140 By default, IPv6 nodes and applications must not treat IPv6 addresses 141 within 64:ff9b:1::/48 different from other globally scoped IPv6 142 addresses. In particular, they must not make any assumptions 143 regarding the syntax or properties of those addresses (e.g., the 144 existence and location of embedded IPv4 addresses), or the type of 145 associated translation mechanism (e.g., whether it is stateful or 146 stateless). 148 64:ff9b:1::/48 or any other more-specific prefix may not be 149 advertised in inter-domain routing, except by explicit agreement 150 between all involved parties. Such prefixes MUST NOT be advertised 151 to the default-free zone. 153 When 64:ff9b:1::/48 or a more-specific prefix is used with the 154 [RFC6052] algorithm, it is considered to be a Network-Specific 155 Prefix. 157 6. Checksum Neutrality 159 Use of 64:ff9b:1::/48 does not in itself guarantee checksum 160 neutrality, as many of the IPv4/IPv6 translation algorithms it can be 161 used with are fundamentally incompatible with checksum-neutral 162 address translations. 164 The Stateless IP/ICMP Translation algorithm [RFC7915] is one well- 165 known algorithm that can operate in a checksum-neutral manner, when 166 using the [RFC6052] algorithm for all of its address translations. 167 However, in order to attain checksum neutrality is imperative that 168 the translation prefix is chosen carefully. Specifically, in order 169 for a 96-bit [RFC6052] prefix to be checksum neutral, all the six 170 16-bit words in the prefix must add up to a multiple of 0xffff. 172 The following non-exhaustive list contains examples of translation 173 prefixes that are checksum neutral when used with the [RFC7915] and 174 [RFC6052] algorithms: 176 o 64:ff9b:1:fffe::/96 178 o 64:ff9b:1:fffd:1::/96 180 o 64:ff9b:1:fffc:2::/96 182 o 64:ff9b:1:abcd:0:5431::/96 184 Section 4.1 of [RFC6052] contains further discussion about IPv4/IPv6 185 translation and checksum neutrality. 187 7. IANA Considerations 189 The IANA is requested to add the following entry to the IPv6 Special- 190 Purpose Address Registry: 192 +----------------------+---------------------+ 193 | Attribute | Value | 194 +----------------------+---------------------+ 195 | Address Block | 64:ff9b:1::/48 | 196 | Name | IPv4-IPv6 Translat. | 197 | RFC | (TBD) | 198 | Allocation Date | (TBD) | 199 | Termination Date | N/A | 200 | Source | True | 201 | Destination | True | 202 | Forwardable | True | 203 | Global | False | 204 | Reserved-by-Protocol | False | 205 +----------------------+---------------------+ 207 The IANA is furthermore requested to add the following footnote to 208 the 0000::/8 entry of the Internet Protocol Version 6 Address Space 209 registry: 211 64:ff9b:1::/48 reserved for Local-use IPv4/IPv6 Translation [TBD] 213 8. Security Considerations 215 The reservation of 64:ff9b:1::/48 is not known to cause any new 216 security considerations beyond those documented in Section 5 of 217 [RFC6052]. 219 9. References 221 9.1. Normative References 223 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 224 Requirement Levels", BCP 14, RFC 2119, 225 DOI 10.17487/RFC2119, March 1997, 226 . 228 [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. 229 Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, 230 DOI 10.17487/RFC6052, October 2010, 231 . 233 9.2. Informative References 235 [RFC7915] Bao, C., Li, X., Baker, F., Anderson, T., and F. Gont, 236 "IP/ICMP Translation Algorithm", RFC 7915, 237 DOI 10.17487/RFC7915, June 2016, 238 . 240 Appendix A. Acknowledgements 242 The author would like to thank Fred Baker, David Farmer, Holger 243 Metschulat and Pier Carlo Chiodi for contributing to the creation of 244 this document. 246 Author's Address 248 Tore Anderson 249 Redpill Linpro 250 Vitaminveien 1A 251 0485 Oslo 252 Norway 254 Phone: +47 959 31 212 255 Email: tore@redpill-linpro.com 256 URI: http://www.redpill-linpro.com