Network Working Group N. Matsuhira Internet-Draft Fujitsu Limited Intended status: Informational K. Horiba Expires: February 26, 2016 Y. Ueno O. Nakamura Keio Univ. August 25, 2015 SA46T Address Translator draft-matsuhira-sa46t-at-06 Abstract This document specifies SA46T Address Translator (SA46T-AT) specification. SA46T-AT enable access to IPv4 only host from IPv6 host. IPv4 host is identified as SA46T global address in IPv6 address space. The address assigned to IPv4 host may be global IPv4 address or private IPv4 address. SA46T-AT does not support access to IPv6 host from IPv4 only host. 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 February 26, 2016. Copyright Notice Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved. Matsuhira, et al. Expires February 26, 2016 [Page 1] Internet-Draft SA46T-AT August 2015 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. SA46T-AT Architecture . . . . . . . . . . . . . . . . . . . . . 3 2.1. SA46T address . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Mapping IPv4 address and IPv6 address . . . . . . . . . . . 4 2.3. AddressTranslation Table . . . . . . . . . . . . . . . . . 4 2.4. DNS mapping of IPv4 only host . . . . . . . . . . . . . . . 4 3. Sample Configuration . . . . . . . . . . . . . . . . . . . . . 4 3.1. SA46T address and IPv4 network plane ID . . . . . . . . . . 4 3.2. Network Configuration . . . . . . . . . . . . . . . . . . . 5 3.3. Routing . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Processing of SA46T-AT . . . . . . . . . . . . . . . . . . . . 6 4.1. Configuration of SA46T-AT . . . . . . . . . . . . . . . . . 6 4.2. Processing from IPv6 to IPv4 . . . . . . . . . . . . . . . 7 4.3. Processing from IPv6 to IPv4 . . . . . . . . . . . . . . . 7 4.4. Other processing . . . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . . 8 8.2. Informative References . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 Matsuhira, et al. Expires February 26, 2016 [Page 2] Internet-Draft SA46T-AT August 2015 1. Introduction The IPv4 address exhaution already became the real. In 03-Feb-2011, IANA Unallocated Address Pool was exhausted. And in 19-Apr-2011, APNIC unallocated address pool was exhaused. Other RIRs, unallocated address pool does not exhaused now, however, it should be a matter of time. For more details, please refer to IPv4 address report , http://www.potaroo.net/tools/ipv4/. After IPv4 address running out, IPv6 only network service should be provided. SA46T [I-D.matsuhira-sa46t-spec] provide IPv4 network service over IPv6 only network environments. And SA46T grobal address [I-D.matsuhira-sa46t-gaddr]is proposed for The Internet scale. On the other side, to maintain the continuance of service by the server, shifting to IPv6 is also needed. However, there should be a service which has difficulty to quick shift to the IPv6. That mean IPv4 service continuance is still important. There are two approaches which use IPv4 address effectively. One is address sharing approach such as Address plus port (A+P) Approach [RFC6346], and the other is address re-use approach such as IPv4 private address [RFC1918]. SA46T-AS [I-D.matsuhira-sa46t-as] is also address sharing approch. SA46T-AT is equivalent to address reuse approach. 2. SA46T-AT Architecture 2.1. SA46T address Figure 1 show SA46T address[I-D.matsuhira-sa46t-spec]. SA46T global address is same format with SA46T address, and "SA46T address prefix" part should allocate for this usage. And "IPv4 network plane ID" value MUST unique. | 96 - m bits | m bits | 32 bits | +-----------------------+--------------------------+--------------+ | SA46T address prefix | IPv4 network plane ID | IPv4 address | +-----------------------+--------------------------+--------------+ Figure 1 Matsuhira, et al. Expires February 26, 2016 [Page 3] Internet-Draft SA46T-AT August 2015 2.2. Mapping IPv4 address and IPv6 address SA46T address contain IPv4 address. Mapping IPv4 host address to IPv6 address space is already done with SA46T address. Address translation for IPv4 address is same as resolving SA46T address. IPv6 host address and corresponding IPv4 address should manage. 2.3. AddressTranslation Table Figure 2 shows translation table for SA46T-AT. Translation table contain three value, IPv6 adddress ot IPv6 host, mapped IPv4 address for the IPv6 host, and extry expire timer for remove the entry. +----------------------+----------------------+--------------------+ | Address of IPv6 host | mapped IPv4 address | entry expire timer | | | for IPv6 host | | +----------------------+----------------------+--------------------+ | : | : | : | ~ : ~ : ~ : ~ | : | : | : | +----------------------+----------------------+--------------------+ | Address of IPv6 host | mapped IPv4 address | entry expire timer | | | for IPv6 host | | +----------------------+----------------------+--------------------+ Figure 2 2.4. DNS mapping of IPv4 only host In the Domain Name System, hostnames are mapped to IPv6 addresses by AAAA resource records. SA46T address can be mapped to IPv4 only host name. 3. Sample Configuration 3.1. SA46T address and IPv4 network plane ID In this example, SA46T address prefix length is 64bits, and IPv4 network plane ID length is 32 bits. SA46T prefix value is 2001:0DB8: 0:46, and IPv4 network plane ID value is 0:46. Figure 3 shows these value. Matsuhira, et al. Expires February 26, 2016 [Page 4] Internet-Draft SA46T-AT August 2015 | 64 bits | 32 bits | 32 bits | +-----------------------+--------------------------+--------------+ | SA46T address prefix | IPv4 network plane ID | IPv4 address | | (2001:0DB8:0:46) | (0:46) | | +-----------------------+--------------------------+--------------+ Figure 3 3.2. Network Configuration Figure 4 shows sample network configuration. IPv6 network have 2001: 0DB8:1:0/64 network prefix and IPv4 network have 10.0.0.0/24 network prefix. +----------------+ | IPv6 host | | 2001:0DB8:1.0::10 +----------------+ | | 2001:0DB8:1:0/64 | +----------------+ | 2001:0DB8:1:0::1 | | | SA46T-AT | | address pool for IPv6 host mapping | 192.168.0.0/24 | | | 10.0.0.1 +----------------+ | | 10.0.0.0/24 | +----------------+ | IPv4 only host | | | | ipv4onlyhost10.example.com | 10.0.0.10 | | (2001:0DB8:0:46:0:64:10.0.0.10) | | +----------------+ Figure 4 Matsuhira, et al. Expires February 26, 2016 [Page 5] Internet-Draft SA46T-AT August 2015 IPv6 host address is 2001:0DB8:1:0::10. IPv4 only host address is 10.0.0.10. SA46T address for IPv4 only host is 2001:0DB8:0:46:0:64: 10.0.0.10. FQDN of IPv4 only host is ipv6onlyhost10.example.com. Figure 5 shows DNS entry in IPv4 address space, and Figure 6 shows DNS entry in IPv6 space. ipv6onlyhost10.example.com IN A 10.0.0.10 Figure 5 ipv6onlyhost10.example.com IN AAAA 2001:0DB8:0:46:0:64:10.0.0.10 Figure 6 The address of IPv4 interface of SA46T-AT is 10.0.0.1, and the address of IPv6 interface of SA46T-AT is 2001:0DB8:1:0::1. SA46T-AT have also IPv4 address pool for IPv6 host mapping. This example, the IPv4 address pool is 192.168.0.0/24. The default router for IPv4 only host is SA46T-AT's IPv4 interface address, 10.0.0.1. 3.3. Routing SA46T-AT advertise SA46T address prefix for IPv4 only host, 2001: 0DB8:0:46:0:64:10.0.0.0/120. This manner is same as SA46T. 4. Processing of SA46T-AT 4.1. Configuration of SA46T-AT 1. SA46T address prefix for route advertisement (2001:0DB8:0:46:0: 64:10.0.0.0/120) 2. IPv4 address pool for IPv6 hosts 3. entry expire default time (TBD) SA46T address contain IPv4 network plane ID, so SA46T-AT know IPv4 network plane ID from SA46T address prefix. Matsuhira, et al. Expires February 26, 2016 [Page 6] Internet-Draft SA46T-AT August 2015 4.2. Processing from IPv6 to IPv4 1. SA46T-AT examine the exists of the entry for IPv6 host, that is source IPv6 address of IPv6 packet. 2. If there is no entry, get IPv4 address for mapping of IPv6 host from IPv4 address pool, and make entry to the translation table. 3. IF there is the entry, resove mapped IPv4 address for IPv6 host. 4. Make IPv4 header, source address is mapped IPv4 address, and destination address is from SA46T address. 5. Translate IPv6 packet to IPv4 packet, and send it, and reset entry expire timer. The example addess translation table is shown in Figure 7. In this example, IPv6 host address is mapped to 192.168.0.200. +----------------------+----------------------+--------------------+ | Address of IPv6 host | mapped IPv4 address | entry expire timer | | | for IPv6 host | | +----------------------+----------------------+--------------------+ | 2001:0DB8:1.0::10 | 192.168.0.200 | TBD | +----------------------+----------------------+--------------------+ Figure 7 4.3. Processing from IPv6 to IPv4 1. Search address translation table with key destination IPv4 address, and resolve corrensponding IPv6 address. 2. Resolve source IPv6 address from sourve IPv4 address with SA46T address generation rule. 3. Translate IPv4 packet to IPv6 packet, and sent it, and reset extry expire timer. 4.4. Other processing 1. Remove the entry of address translation table if expire. Matsuhira, et al. Expires February 26, 2016 [Page 7] Internet-Draft SA46T-AT August 2015 5. IANA Considerations This document may requests IANA to assign IPv6 prefix for SA46T Global address. 6. Security Considerations Security consideration does not discussed in this memo, at this time. 7. Acknowledgements 8. References 8.1. Normative References [I-D.matsuhira-sa46t-as] Matsuhira, N., "Stateless Automatic IPv4 over IPv6 Tunneling with IPv4 Address Sharing", draft-matsuhira-sa46t-as-05 (work in progress), July 2013. [I-D.matsuhira-sa46t-gaddr] Matsuhira, N., "Stateless Automatic IPv4 over IPv6 Encapsulation / Decapsulation Technology: Global SA46T Address Format", draft-matsuhira-sa46t-gaddr-07 (work in progress), July 2013. [I-D.matsuhira-sa46t-spec] Matsuhira, N., "Stateless Automatic IPv4 over IPv6 Encapsulation / Decapsulation Technology: Specification", draft-matsuhira-sa46t-spec-07 (work in progress), July 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 8.2. Informative References [RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and E. Lear, "Address Allocation for Private Internets", BCP 5, RFC 1918, February 1996. [RFC3849] Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix Reserved for Documentation", RFC 3849, July 2004. [RFC6346] Bush, R., "The Address plus Port (A+P) Approach to the Matsuhira, et al. Expires February 26, 2016 [Page 8] Internet-Draft SA46T-AT August 2015 IPv4 Address Shortage", RFC 6346, August 2011. Authors' Addresses 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 Katsuhiro Horiba Keio Univ. 5322 Endo Fujisawa, 252-8520 Japan Phone: Fax: Email: qoo@sfc.wide.ad.jp URI: Yukito Ueno Keio Univ. 5322 Endo Fujisawa, 252-8520 Japan Phone: Fax: Email: eden@sfc.wide.ad.jp URI: Matsuhira, et al. Expires February 26, 2016 [Page 9] Internet-Draft SA46T-AT August 2015 Osamu Nakamura Keio Univ. 5322 Endo Fujisawa, 252-8520 Japan Phone: Fax: Email: osamu@wide.ad.jp URI: Matsuhira, et al. Expires February 26, 2016 [Page 10]