Internet-Draft L. Zheng Intended status: Informational ZTE Expires: September 30, 2010 March 29, 2010 PNAT with dual IPv6 Addresses draft-zheng-pnat-dual-v6addr-00 Abstract This document describes a derived PNAT mechanism that hosts do not need IPv4 addresses, neither public, private nor faked IPv4 address. PNAT solution was first proposed by Huang & Deng in [PNAT], which provides application-level transparency for hosts in IPv4 and IPv6 hybrid environments via host-based IPv4/IPv6 translation technique. This specification addresses one of the PNAT scenarios where a host is provided IPv6 only network connectivity. Two IPv6 addresses will be assigned to a PNAT host. One is native IPv6 address, and the other is a PNAT IPv6 address. In this case, IPv4- originated communications still need to be translated into IPv6. However, the host does not need to be assigned an IPv4 address. Instead, a PNAT IPv6 address will take the place of the originally required IPv4 address.Two formats of PNAT IPv6 address,4rd (IPv4 Rapid Deployment) address and 4rm (IPv4 Rapid Migration) address, are defined. The advantage of the derived PNAT mechanism is that such IPv6 PNAT host supports both IPv4 and IPv6 applications, with SIMPLICITY, SCALABILITY and without worrying about any IPv4 address allocating issue. 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 L. Zheng Expires September 30, 2010 [Page 1] Internet-Draft PNAT with dual IPv6 Addresses March 2010 http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on September 30, 2010. Copyright Notice Copyright (c) 2010 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 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 BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Problem Statement and Purpose of PNAT with dual IPv6 addresses . 3 3. Specification . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. IPv4 Rapid Migration . . . . . . . . . . . . . . . . . . . . . . 4 5. DNS Considerations . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction PNAT solution was first proposed by Huang and Deng in [PNAT]. The biggest advantage of PNAT solution is that it can provide backward compatibility for IPv4 applications in IPv6 environments. Any user may simply install an IPv4 application (with no modifications) on a PNAT host, and is able to start using it to access IPv4 world without any problem, even with IPv6 only connectivity. PNAT host could run in both dual stack and IPv6-only network, depending on the operator policy. In [PNAT], authors mentioned about four cases that the PNAT host get address assignment from the L. Zheng Expires September 30, 2010 [Page 2] Internet-Draft PNAT with dual IPv6 Addresses March 2010 network, which are PNAT with public IPv4 address, PNAT with private IPv4 address, PNAT with faked IPv4 address, and PNAT with single IPv6 address. This specification addresses one of the PNAT scenarios where a host is provided IPv6 only network connectivity. The fifth PNAT addressing solution is proposed, PNAT with dual IPv6 addresses. In this case, two IPv6 addresses will be assigned to a PNAT host. One is native IPv6 address, and the other is a PNAT IPv6 address. IPv4- originated communications still need to be translated into IPv6. However, the host does not need to be assigned a IPv4 address. Instead, the PNAT IPv6 address will take the place of the originally required IPv4 address. Two types of PNAT IPv6 addresses, 4rd (IPv4 Rapid Deployment) address and 4rm (IPv4 Rapid Migration) address, are defined. The advantage of the derived PNAT mechanism is that, without scarifying PNAT basic functionality, it further supports IPv4 service rapid migration, with SIMPLICITY, and SCALABILITY. 2. Problem Statement and Purpose of PNAT with dual IPv6 addresses PNAT with IPv4 address solutions, inherit the IPv4 space limitations. The public IPv4 address is depleting, and the private IPv4 address space has the 17 million maximum capacity limitation according to RFC1918. Although PNAT with single IPv6 address solution does not have above problems, it does bring some extra complicity on the host PNAT module implementation compared with dual IPv6 addresses solution. Considering the abundance of the IPv6 addresses, and the IPv4 Service rapid migration benefit it may bring, PNAT with dual IPv6 addresses is presented. In these two IPv6 addresses, one is native IPv6 address, and the other is PNAT IPv6 address. The native IPv6 address is for IPv6 applications, while the PNAT IPv6 address is for IPv4 applications, including IPv4 both client applications and server applications. Two types of PNAT IPv6 addresses are defined. PNAT 4rd (IPv4 Rapid Deployment) IPv6 address, is for host mainly running IPv4 client applications, and PNAT 4rm (IPv4 Rapid Migration) IPv6 address is mainly for host running IPv4 server applications. 3. Specification L. Zheng Expires September 30, 2010 [Page 3] Internet-Draft PNAT with dual IPv6 Addresses March 2010 Two types of PNAT IPv6 addresses, 4rd (IPv4 Rapid Deployment) address and 4rm (IPv4 Rapid Migration) address, are defined as below. +---------------//-------.------.------------------------+ | Allocated IPv6 prefix | | | | of the ISP | 2003 | E.164 Number | +---------------//-------'------'------------------------+ Figure 1: Format of the PNAT 4rd IPv6 Prefix +---------------//-------.------.------------------------+ | Allocated IPv6 prefix | | IPv4 address | | of the ISP | 2004 | of the migrated Host | +---------------//-------'------'------------------------+ Figure 2: Format of the PNAT 4rm IPv6 Prefix Notes: the 2003 and 2004 in Figure 1 and Figure 2 are just examples, ISP may choose some other numbers to distinguish two different types of PNAT IPv6 Prefixes/addresses inside its networks. However, if more than one ISPs want to share their PNAT IPv4 services, it will be necessary to have globally unique well known numbers for all participated ISPs, for easy implementation and interoperability. The overall communication mechanism remains the same with other PNAT solutions. Please refer to [PNAT] for more details. 4. IPv4 Rapid Migration When we talk about IPv4 Rapid Deployment, it means to rapidly bring the PNAT host the ability to run IPv4 applications to access traditional IPv4 services. While at the same time, PNAT with dual IPv6 addresses also provides the possibility to rapidly migrate existing IPv4 Server onto IPv6 Infrastructures. The foreseeable cost of such migration is to implement PNAT module on the host (Server), and to get a PNAT 4rm address configured. IPv6 routing remains unchanged in the scores of both ISP IPv6 networks and IPv6 Internet. The IPv6 Internet routing table will not show the PNAT IPv6 Prefix routing entries, since PNAT IPv6 Prefixes are aggregated into ISP's allocated prefixes. Cross ISP PNAT IPv4 communications can be also supported without L. Zheng Expires September 30, 2010 [Page 4] Internet-Draft PNAT with dual IPv6 Addresses March 2010 extra cost. 5. DNS Considerations In order to support PNAT IPv4 clients visiting PNAT IPv4 servers and to support the communication between PNAT hosts, some DNS functions need to be extended. Discussion of DNS solutions is out of the scope of this document. But surely there are some works need to be done and can be done on the DNS server. L. Zheng Expires September 30, 2010 [Page 5] Internet-Draft PNAT with dual IPv6 Addresses March 2010 6. Security Considerations Packets originated from a host with PNAT IPv6 address can only target to either a traditional IPv4 server (with WKP+V4ADDR IPv6 address format), or another host with PNAT IPv6 address. Consequently, the transit routers may drop any packets that does not meet such requirements, to further improve network security and offload the network transportation. 7. Acknowledgments The author gratefully acknowledge the many helpful previous works from our IETF authors in the development of this document. Their insights and hard works make Internet and our lives better. 8. References [TRANS-MECH] Gilligan, R. and E. Nordmark, "Transition Mechanisms for IPv6 Hosts and Routers", RFC 2893, August 2000. [NAT] Srisuresh, P. and K. Egevang, "Traditional IP Network Address Translator (Traditional NAT)", RFC 3022, January 2001. [IPV4] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981. [IPV6] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [BIS] Tsuchiya, K., Higuchi, H. and Y. Atarashi, "Dual Stack Hosts using the "Bump-In-the-Stack" Technique (BIS)", RFC 2767, February 2000. [BIA] S. Lee, M., Shin, Y. Kim, A. Durand and E. Nordmark, "Dual Stack Hosts Using "Bump-in-the-API" (BIA)", RFC 3338, October 2002. [DNS64] Bagnulo, M., Sullivan, A., Matthews, P., van Beijnum, I., "DNS64: DNS extensions for Network Address Translation from IPv6 Clients to IPv4 Servers", draft- ietf-behave-dns64-00, July 2009, work-in-progress [ADDRFORMAT] Huitema, C., Bao, C., Bagnulo, M., Boucadair, M., Li, X., "IPv6 Addressing of IPv4/IPv6 Translators", draft- ietf-behave-address-format-00, August 2009, work-in- L. Zheng Expires September 30, 2010 [Page 6] Internet-Draft PNAT with dual IPv6 Addresses March 2010 progress [NAT64] Bagnulo, M., Matthews, P., van Beijnum, I., "NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", draft-ietf-behave-v6v4-xlate- stateful-01, July 2009, work-in-progress [PNAT] Huang, B., Deng, H., "Prefix NAT: Host based IPv6 translation", draft-huang-behave-pnat-01, February, 2010, work-in-progress L. Zheng Expires September 30, 2010 [Page 7] Internet-Draft PNAT with dual IPv6 Addresses March 2010 Author's Address Linfeng Zheng ZTE No.68 Zijinghua Rd, Yuhuatai District, Nanjing 210012 P.R.China Email: zheng.linfeng@zte.com.cn L. Zheng Expires September 30, 2010 [Page 8]