One document matched: draft-zheng-pnat-dual-v6addr-00.txt

 



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
 


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   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
 


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   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

 


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   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
 


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   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. 






































 


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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-
 


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                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






































 


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Author's Address

      Linfeng Zheng
      ZTE
      No.68 Zijinghua Rd,
      Yuhuatai District,
      Nanjing 210012
      P.R.China

      Email: zheng.linfeng@zte.com.cn









































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