Network Working Group N. Matsuhira Internet-Draft Fujitsu Limited Intended status: Experimental March 26, 2012 Expires: September 27, 2012 SA46T Multicast Support draft-matsuhira-sa46t-mcast-01 Abstract This document describe Stateless Automatic IPv4 over IPv6 Encapsulation / Decapsutation Technology (SA46T) multicast support. IPv4 multicast is supported by SA46T with same manner with IPv4 unicast. SA46T multicast address prefix is defined. Requirements Language 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 RFC 2119 [RFC2119]. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 27, 2012. Copyright Notice Copyright (c) 2012 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 Matsuhira Expires September 27, 2012 [Page 1] Internet-Draft SA46T multicast March 2012 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. Architecture of SA46T Multicast . . . . . . . . . . . . . . . . 3 3. Format of SA46T Multicast address . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . . 7 7.2. References . . . . . . . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Matsuhira Expires September 27, 2012 [Page 2] Internet-Draft SA46T multicast March 2012 1. Introduction This document describe Stateless Automatic IPv4 over IPv6 Encapsulation / Decapsulation Technology (SA46T) multicast support. SA46T [I-D.draft-matsuhira-sa46t-spec] makes backbone network to IPv6 only. And also, SA46T can stack many IPv4 networks, i.e. the networks using same IPv4 (private) address, without interdependence. IPv4 multicast is supported by SA46T with same manner with IPv4 unicast. 2. Architecture of SA46T Multicast IPv4 multicast address is knows as Class D IPv4 address, 224.0.0.0/4. The range is from 224.0.0.0 to 239.255.255.255. Mapping IPv4 multicast address to IPv6 addressing space, the IPv6 address which mapped to IPv4 mapped address is also IPv6 multicast address space, because copy of the packet for multicasting may occuer not only in IPv4 subnet but also in IPv6 backbone. So, SA46T multicast support require special IPv6 address prefix, SA46T multicast address prefix. Figure 1 show address architecutire of SA46T and SA46T multicast support. Both unicast case and multicast case, mapping IPv4 address is the same, and usage of IPv4 network plane ID is the same, however, SA46T address prefix (unicast) and SA46T multicast address prefix is not the same. If value of IPv4 network plane ID is the same, IPv4 unicast address and IPv4 multicast address belong the same network plane. In this document, SA46T unicast address which contain IPv4 unicast address, and SA46T multicast address which contain IPv4 multicast address are used. Matsuhira Expires September 27, 2012 [Page 3] Internet-Draft SA46T multicast March 2012 |<------------------------ 128 bits ----------------------------->| |<-------------------- 96 bits ------------------->|<-- 32 bits ->| | | | | | +--------------+ | | IPv4 address | | +--------------+ | | | | 96 - m bits | m bits | 32 bits | +-----------------------+--------------------------+--------------+ | SA46T address prefix | IPv4 network plane ID | IPv4 address | | ( unicast ) | | (unicast) | +-----------------------+--------------------------+--------------+ | | | | +-----------------------+--------------------------+--------------+ | SA46T multicast | IPv4 network plane ID | IPv4 address | | address prefix | | (multicast) | +-----------------------+--------------------------+--------------+ Figure 1 Figure 2 show the format of SA46T multicast address prefix. IPv6 multicast address has a prefix of FF00::/8. SA46T multicast address prefix should be the same with IPv6 multicast address prefix. A group ID part of IPv6 multicast address is mapped with reserve space, IPv4 network plane ID, and IPv4 (multicast) address. Matsuhira Expires September 27, 2012 [Page 4] Internet-Draft SA46T multicast March 2012 | 4 | 28 | +----+------------+ |1110| | +----+------------+ | IPv4 multicast | | address | | | | +-------------------------------+---------------+-----------------+ |SA46T multicast address plefix | IPv4 plane ID | IPv4 address | +-------------------------------+---------------+-----------------+ | 8 | 4 | 4 |112 - m - 32| m | 32 | +------ -+----+----+----------------------------------------------+ |11111111|flgs|scop| rsv | IPv4 plane ID | IPv4 address | +--------+----+----+----------------------------------------------+ : : : : : : : : : : | 8 | 4 | 4 | 112 bits | +--------+----+----+----------------------------------------------+ |11111111|flgs|scop| group ID | +--------+----+----+----------------------------------------------+ Figure 2 The information which indicate SA46T multicast address is needed, because there is a possibility the value of group ID for IPv6 multicast and the value of "rsv+IPv4 network plane ID + IPv4 multicast addres" is the same. This information is TBD. However, this version of this document supporse using flag space. The flag space consists four flags (bits), and high-order 3 flags are reserced, and 4th flag is T, which indicate the address is permanently-assinged (well-known) or non-parmanently-assinged (transient). There is a idea, which allocate SA46T multicast address flag in flag space, and using scop space also other idea, too 3. Format of SA46T Multicast address This example is based on IPv6 Global Unicast Address Format [RFC3587]. Figure 3 shows IPv6 Global Unicast Address Format. Matsuhira Expires September 27, 2012 [Page 5] Internet-Draft SA46T multicast March 2012 | 3 | 45bits | 16bits | 64bits | +---+-----------------------+-----------+--------------------------+ |001| Global routing prefix | subnet id | Interface ID | +---+-----------------------+-----------+--------------------------+ Figure 3 Figure 4 shows SA46T multicast address format using part of IPv6 Global Unicast Address. | 3 | 45bits | 16bits | 32bits | 32bits | +---+-----------------------+-----------+--------------------------+ |001| Global routing prefix | subnet id | plane ID | IPv4 address | +---+-----------------------+-----------+--------------------------+ <---SA46T address prefix---------------> | 8 | 4 | 4 | 48 | 32 | 32 | +------=-+----+----+--------------------+-----------+--------------+ |11111111|flgs|scop| rsv | plane ID | IPv4 address | +--------+----+----+--------------------+-----------+--------------+ <---SA46T multicast address prefix-----> Figure 4 4. IANA Considerations This document may make request of IANA. 5. Security Considerations SA46T use automatic encapsulation technologies. Security consideration related tunneling technologies are discussed in RFC2893[RFC2893], RFC2267[RFC2267], etc. 6. Acknowledgements 7. References Matsuhira Expires September 27, 2012 [Page 6] Internet-Draft SA46T multicast March 2012 7.1. Normative References [I-D.draft-matsuhira-sa46t-spec] Matsuhira, N., "Stateless Automatic IPv4 over IPv6 Encapsulation / Decapsulation Technology: Specification", January 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3587] Hinden, R., Deering, S., and E. Nordmark, "IPv6 Global Unicast Address Format", RFC 3587, August 2003. 7.2. References [RFC2267] Ferguson, P. and D. Senie, "Network Ingress Filtering: Defeating Denial of Service Attacks which employ IP Source Address Spoofing", RFC 2267, January 1998. [RFC2893] Gilligan, R. and E. Nordmark, "Transition Mechanisms for IPv6 Hosts and Routers", RFC 2893, August 2000. Author's Address Naoki Matsuhira Fujitsu Limited 1-1, Kamikodanaka 4-chome, Nakahara-ku Kawasaki, 211-8588 Japan Phone: +81-44-754-3466 Fax: Email: matsuhira@jp.fujitsu.com Matsuhira Expires September 27, 2012 [Page 7]