INTERNET-DRAFT Cameron Byrne Updates: 6333 (if approved) T-Mobile US Intended Status: Standards Track August 4, 2014 Expires: February 5, 2015 IPv4 Service Continuity Prefix draft-ietf-v6ops-clatip-04 Abstract DS-Lite, defined in RFC 6333, directs IANA to reserve 192.0.0.0/29 for the B4 element. This memo directs IANA to generalize that reservation to include other cases where a non-routed IPv4 interface must be numbered as part of an IPv6 transition solution. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License Notice Copyright (c) 2014 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 Byrne Expires February 5, 2015 [Page 1] INTERNET DRAFT IPv4 Service Continuity Prefix August 4, 2014 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. The Case of 464XLAT . . . . . . . . . . . . . . . . . . . . . 3 4. Choosing 192.0.0.0/29 . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Byrne Expires February 5, 2015 [Page 2] INTERNET DRAFT IPv4 Service Continuity Prefix August 4, 2014 1. Introduction DS-Lite [RFC6333] directs IANA to reserve 192.0.0.0/29 for the Basic Bridging BroadBand (B4) element. This memo generalizes that IANA reservation to include other cases where a non-routed IPv4 interface must be numbered in an IPv6 transition solution. IANA shall list the address block 192.0.0.0/29 reserved for IPv4 Service Continuity Prefix. The result is that 192.0.0.0/29 may be used in any system that requires IPv4 addresses for backward compatibility with IPv4 communications in an IPv6-only network, but does not emit IPv4 packets "on the wire". This generalization does not impact the use of the IPv4 Service Continuity Prefix in a DS-Lite context. 2. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. The Case of 464XLAT 464XLAT [RFC6877] describes an architecture for providing IPv4 communication over an IPv6-only access network. One of the methods described in [RFC6877] is for the client side translator (CLAT) to be embedded in the host, such as a smartphone or a CPE (Customer Premises Equipment). In such scenarios, the host must have an IPv4 address configured to present to the host network stack and for applications to bind IPv4 sockets. 4. Choosing 192.0.0.0/29 To avoid conflicts with any other network that may communicate with the CLAT or other IPv6 transition solution, a locally unique IPv4 address must be assigned. IANA has defined a well-known range, 192.0.0.0/29, in [RFC6333], which is dedicated for DS-Lite. As defined in [RFC6333], this subnet is only present between the B4 and the AFTR and never emits packets from this prefix "on the wire". 464XLAT has the same need for a non- routed IPv4 prefix, and this same need may be common for other similar solutions. It is most prudent and effective to generalize 192.0.0.0/29 for the use of supporting IPv4 interfaces in IPv6 transition technologies rather than reserving a prefix for every possible solution. Byrne Expires February 5, 2015 [Page 3] INTERNET DRAFT IPv4 Service Continuity Prefix August 4, 2014 With this memo, 192.0.0.0/29 is now generalized across multiple IPv4 continuity solutions such as 464XLAT and DS-lite. A host MUST NOT enable two active IPv4 continuity solutions simultaneously in a way that would cause a node to have overlapping 192.0.0.0/29 address space. 5. Security Considerations No new security considerations beyond what is described [RFC6333] and [RFC6877]. 6. IANA Considerations This document requests IANA to update the IPv4 Special-Purpose Address Registry available at (http://www.iana.org/assignments/iana- ipv4-special-registry/iana-ipv4-special-registry) as follows: OLD: 192.0.0.0/29 DS-Lite [RFC6333] NEW: 192.0.0.0/29 IPv4 Service Continuity Prefix [RFC-to-be-xxx] +----------------------+-----------------------------------+ | Attribute | Value | +----------------------+-----------------------------------+ | Address Block | 192.0.0.0/29 | | Name | IPv4 Service Continuity Prefix | | RFC | RFC TBD | | Allocation Date | June 2014 | | Termination Date | N/A | | Source | True | | Destination | True | | Forwardable | True | | Global | False | | Reserved-by-Protocol | False | +----------------------+-----------------------------------+ 7. Acknowledgements This document has been substantially improved by specific feedback from Dave Thaler, Fred Baker, Wes George, Lorenzo Colitti, and Mohamed Boucadair. Byrne Expires February 5, 2015 [Page 4] INTERNET DRAFT IPv4 Service Continuity Prefix August 4, 2014 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC6333, August 2011. [RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT: Combination of Stateful and Stateless Translation", RFC6877, April 2013. Authors' Addresses Cameron Byrne Bellevue, WA, USA Email: Cameron.Byrne@T-Mobile.com Byrne Expires February 5, 2015 [Page 5]