[Docs] [txt|pdf|xml] [Tracker] [Email] [Nits]

Versions: 00

DHC Working Group                                                W. Wang
Internet-Draft                                                  L. Zhang
Intended status: Standards Track                                  X. Que
Expires: March 19, 2015                                  BUPT University
                                                                   L. Li
                                                     Tsinghua University
                                                                 Y. Wang
                                                         BUPT University
                                                      September 15, 2014


                Discovery of the IPv6 Prefix in 464XLAT
               draft-wang-v6ops-xlat-prefix-discovery-00

Abstract

   The 464XLAT[RFC6877] provides a solution with limited IPv4
   connectivity across an IPv6-only network.  In the architecture, the
   CLAT must discover the PLAT-side translation IPv6 prefix.  This
   document defines a mechanism for CLAT to learn the IPv6 prefix used
   for protocol translation on an access network.

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 March 19, 2015.

Copyright 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
   publication of this document.  Please review these documents



Wang, et al.             Expires March 19, 2015                 [Page 1]


Internet-Draft            IPv6 Prefix Discovery           September 2014


   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   2
   3.  Solution Overview . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Client-Server Interaction . . . . . . . . . . . . . . . . . .   3
   5.  DHCPv6 Options  . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  PLAT IPv6 PREFIX Option . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   464XLAT describes an IPv4-over-IPv6 solution as one of the techniques
   for IPv4 service extension and encouragement of IPv6 deployment.  The
   464XLAT architecture uses IPv4/IPv6 translation standardized in
   [RFC6145] and [RFC6146].  It encourages the IPv6 transition by making
   IPv4 service reachable across IPv6-only networks and providing IPv6
   and IPv4 connectivity to single-stack IPv4 or IPv6 servers and peers.

   Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis
   [RFC7050] describes a method for detecting the presence of DNS64 and
   for learning the IPv6 prefix used for protocol translation on an
   access network.  But it is difficult and depends on DNS64.

   This document defines a mechanism for CLAT to learn the IPv6 prefix
   used for protocol translation on an access network.  One new DHCPv6
   option is defined to inform the CLAT of the IPv6 prefix used for IPv6
   address synthesis.

2.  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 [RFC2119].






Wang, et al.             Expires March 19, 2015                 [Page 2]


Internet-Draft            IPv6 Prefix Discovery           September 2014


3.  Solution Overview

   In the 464XLAT architecture, the CLAT must discover the PLAT-side
   translation IPv6 prefix used as a destination of the PLAT.  The CLAT
   will use this prefix as the destination of all translation packets
   that require stateful translation to the IPv4 Internet.

   The CLAT implements OPTION_V6_PLATPREFIX, which is a DHCPv6 option
   containing the IPv6 prefix used as a destination of the PLAT.  The
   client includes this option within the ORO option in its DHCPv6
   request, indicates its support for the IPv6 prefix to the DHCP
   server.

   OPTION_V6_PLATPREFIX is also implemented by the server to identify
   the client which support IPv6 prefix.  With this option, the server
   informs the client of the IPv6 prefix used as a destination of the
   PLAT.

4.  Client-Server Interaction

   The following diagram shows the client/server message flow and how
   the DHCPv6 option OPTION_V6_PLATPREFIX is used.  In each step, the
   relevant DHCPv6 message is given above the arrow and the
   OPTION_V6_PLATPREFIX below the arrow.



























Wang, et al.             Expires March 19, 2015                 [Page 3]


Internet-Draft            IPv6 Prefix Discovery           September 2014


    DHCPv6 Client                                           DHCPv6 Server
           |                   Solicit                            |
    Step 1 |----------------------------------------------------->|
           |            ORO with OPTION_V6_PLATPREFIX             |
           |                                                      |
           |                  ADVERTISE                           |
    Step 2 |<-----------------------------------------------------|
           |        OPTION_V6_PLATPREFIX (platv6-prefix with      |
           |          PLAT-side translation IPv6 prefix)          |
           |                                                      |
           |                   REQUEST                            |
    Step 3 |----------------------------------------------------->|
           |        OPTION_V6_PLATPREFIX (platv6-prefix with      |
           |          CLAT-side translation IPv6 prefix)          |
           |                                                      |
           |                     REPLY                            |
    Step 4 |<-----------------------------------------------------|
           |        OPTION_V6_PLATPREFIX (platv6-prefix with      |
           |          CLAT-side translation IPv6 prefix)          |
           |                                                      |


               Figure 1: Server/Client Interaction Procedure

   The DHCPv6 Server and Client MAY implement the OPTION_V6_PLATPREFIX.
   A Client that intends to dynamically discover the PLAT-side
   translation IPv6 prefix SHOULD include the code of
   OPTION_V6_PLATPREFIX in the ORO when it sends a Solicit message.

   When a DHCPv6 server replies with a ADVERTISE message, it SHOULD
   include the platv6-prefix with PLAT-side transition IPv6 prefix.  The
   OPTION_V6_PLATPREFIX is used by the server to inform the client of
   the PLAT-side transition IPv6 prefix.

   When the client sends a REQUEST message, it SHOULD include the
   platv6-prefix with CLAT-side translation IPv6 prefix.  The
   OPTION_V6_PLATPREFIX is used by the client to inform the server of
   the transition IPv6 prefix.

5.  DHCPv6 Options

5.1.  PLAT IPv6 PREFIX Option









Wang, et al.             Expires March 19, 2015                 [Page 4]


Internet-Draft            IPv6 Prefix Discovery           September 2014


         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |   OPTION_V6_PLATPREFIX       |         option-length         |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        | platv6-prelen |                                               |
        +-+-+-+-+-+-+-+-+          platv6-prefix                       .
        .                       (variable length)                      .
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   o  option-code: OPTION_V6_PLATPREFIX (TBA1)

   o  option-length: 1 + length of platv6-prefix, specified in bytes.

   o  platv6-prelen: 8-bit field expressing the bit mask length of the
      IPv6 prefix specified in platv6-prefix.

   o  platv6-prefix: The IPv6 prefix that the server uses to inform the
      client of the IPv6 prefix used for IPv6 address synthesis.

6.  Security Considerations

   TBA

7.  IANA Considerations

   This document defines one new DHCPv6 option, the OPTION_V6_PLATPREFIX
   option in Section 4.

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.

8.2.  Informative References

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
              and M. Carney, "Dynamic Host Configuration Protocol for
              IPv6 (DHCPv6)", RFC 3315, July 2003.

Authors' Addresses







Wang, et al.             Expires March 19, 2015                 [Page 5]


Internet-Draft            IPv6 Prefix Discovery           September 2014


   Wendong Wang
   BUPT University
   Beijing University of Posts and Telecommunications (BUPT)
   Beijing  100876
   P.R.China

   Phone: +86-10-6228-1175
   Email: wdwang@bupt.edu.cn


   Lanshan Zhang
   BUPT University
   Beijing University of Posts and Telecommunications (BUPT)
   Beijing  100876
   P.R.China

   Phone: +86-13146885878
   Email: zls326@sina.com


   Xirong Que
   BUPT University
   Beijing University of Posts and Telecommunications (BUPT)
   Beijing  100876
   P.R.China

   Phone: +86-10-6228-3411
   Email: rongqx@bupt.edu.cn


   Lishan Li
   Tsinghua University
   Beijing  100084
   P.R.China

   Phone: +86-15201441862
   Email: lilishan9248@126.com


   Yuqi Wang
   BUPT University
   Beijing University of Posts and Telecommunications (BUPT)
   Beijing  100876
   P.R.China

   Email: wyqbupt@163.com





Wang, et al.             Expires March 19, 2015                 [Page 6]


Html markup produced by rfcmarkup 1.129b, available from https://tools.ietf.org/tools/rfcmarkup/