Network Working Group                                       N. Matsuhira
Internet-Draft                                           Fujitsu Limited
Intended status: Informational                           August 10, 2016
Expires: February 11, 2017


 Multiple IPv4 - IPv6 address mapping encapsulation - prefix resolution
                               (M46E-PR)
                       draft-matsuhira-m46e-pr-01

Abstract

   This document specifies M46E Prefix Resolution (M46E-PR)
   specification.  M46E-PR connect IPv4 stub networks between IPv6
   backbone network.  And also, M46E-PR can stack many IPv4 networks,
   i.e. the nwtworks using same IPv4 private addresses without
   interdependence.

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
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   This Internet-Draft will expire on February 11, 2017.

Copyright Notice

   Copyright (c) 2016 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



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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Basic Network Configuration . . . . . . . . . . . . . . . . . . 3
   3.  Basic Function of M46E-PR . . . . . . . . . . . . . . . . . . . 4
     3.1.  IPv4 over IPv6 Encapsulation / Decapsulation  . . . . . . . 4
     3.2.  M46A architecture . . . . . . . . . . . . . . . . . . . . . 4
     3.3.  Resolving M46A  . . . . . . . . . . . . . . . . . . . . . . 5
   4.  Mode of M46E-PR . . . . . . . . . . . . . . . . . . . . . . . . 6
     4.1.  Router mode . . . . . . . . . . . . . . . . . . . . . . . . 6
     4.2.  Host mode . . . . . . . . . . . . . . . . . . . . . . . . . 6
   5.  Sample configuration  . . . . . . . . . . . . . . . . . . . . . 7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . . . 8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 8
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 8
























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1.  Introduction

   This document provide M46E Prefix Resolution (M46E-PR) specification.

   The basic strategy for IPv6 deployment is dual stack.  However,
   because of exhaustion of IPv4 address, there will be no IPv4
   addresses for configuring dual stack in near future.  That means
   there will be IPv6 only networks automatically.

   However, there are many IPv4 only networks still exist and those
   seems continuous use in near future.  That means methods continuous
   use of IPv4 network over IPv6 only network will be required.

   M46E-PR also provide such methots.


2.  Basic Network Configuration

   Figure 1 shows network configuration with M46E-PR.  The network
   consists of three parts, backbone network, stub network, and M46E-PR.

   Backbone network can be operated with IPv6 only.  Stub network has
   three cases, IPv4 only, Dual Stack (both IPv4 and IPv6), and IPv6
   only.

   M46E-FP connects backbone network and stub network in case IPv4 still
   works in that stub network.  If stub network is IPv6 only, M46E-PR is
   not needed.

       /---------------------------------------------------\
       |                                                   |
       |                  Backbone Network                 |
       |                    (IPv6 only)                    |
       |                                                   |
       \---------------------------------------------------/
              |                   |                |
              |                   |                |
              |                   |                |
         +----------+       +----------+           |
       /-| M46E-PR  |-\   /-| M46E-PR  |-\   /--------------\
       | +----------+ |   | +----------+ |   |              |
       |              |   |              |   |              |
       | Stub Network |   | Stub Network |   | Stub Network |
       | (IPv4 only)  |   | (Dual Stack) |   | (IPv6 only)  |
       |              |   |              |   |              |
       \--------------/   \--------------/   \--------------/





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                                 Figure 1


3.  Basic Function of M46E-PR

   M46E-PR has mainly two function.  One is IPv4 over IPv6 Encapsulation
   / Decapsulation, and another is generate a table where IPv4 stub
   network belong to IPv6 network.

3.1.  IPv4 over IPv6 Encapsulation / Decapsulation

   M46E-PR excapsulates IPv4 packet to IPv6 from stub network to
   backbone network, and decapsulates IPv6 packet to IPv4 from backbone
   network to stub network.  Figure 2 shows packet format on both
   backbone network and stub network.


     +--------+------------+       +----------+--------+------------+
     |IPv4 Hdr|    Data    |  -->  | IPv6 Hdr |IPv4 Hdr|    Data    |
     +--------+------------+       +----------+--------+------------+

     +--------+------------+       +----------+--------+------------+
     |IPv4 Hdr|    Data    |  <--  | IPv6 Hdr |IPv4 Hdr|    Data    |
     +--------+------------+       +----------+--------+------------+


    /-------------------\  +----------+  /-----------------------------\
    |   Stub Network    |--| M46E-PR  |--|       Backbone Network      |
    |      (IPv4)       |  +----------+  |         (IPv6 only)         |
    \-------------------/                \-----------------------------/



                                 Figure 2

3.2.  M46A architecture

   M46A is a IPv6 address used in outer IPv6 header which encapsulate
   IPv4 packet by M46E-PR.  M46A is described in
   [I-D.draft-matsuhira-m46a].Figure 3 shows M46A address architecture.

    |        96 - m bits       |         m bits         |     32 bits  |
    +--------------------------+------------------------+--------------+
    |        M46A prefix       | IPv4 network plane ID  | IPv4 address |
    +--------------------------+------------------------+--------------+

                                 Figure 3




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   M46E address consists of three parts as follows.

   M46A prefix

      M46A prefix.  This value is not a fixed value, and resolved packet
      by packet

   IPv4 network plane ID  IPv4 network plane ID is an identifier of IPv4
      network stack over IPv6 backbone network.

   IPv4 address

      IPv4 address in inner IPv4 packet.

3.3.  Resolving M46A

   M46E-PR resolve M46A using M46E Prefix Resolution Table (M46E-PR
   Table).  M46E-PR generate M46E-PR address resolving M46A prefix from
   IPv4 network plane ID and IPv4 address.  FigureFigure 4 show this
   processing.

    |        96 - m bits       |         m bits         |     32 bits  |
    +--------------------------+------------------------+--------------+
    |        M46A prefix       | IPv4 network plane ID  | IPv4 address |
    +--------------------------+------------------------+--------------+

    \--------------------------/\--------------------------------------/
               ^                                     |
               |                                     |
               |                                     v
    +------------------------------------------------------------------+
    |                                                                  |
    |        M46E Prefix Resolution Table (M46E-PR Table)              |
    |                                                                  |
    +------------------------------------------------------------------+

                                 Figure 4

   Figure Figure 5show M46E-PR Table.  This table consists four parts,
   IPv4 network plane ID, IPv4 address, netmask, and M46A prefix.











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   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+
                 :              :               :
   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+

                                 Figure 5

   M46E-PR configured IPv4 network plane ID, so M46E-PR know IPv4
   network plane ID value the interface belongs.

   Resolving destination address, M46E-PR use pre-configured IPv4
   network plane ID valude, and destination address of IPv4 packets, and
   serch the M46E-PR table.  M46E-PR table return the M46E-PR address
   prefix value correspoiding IPv4 network plane ID and IPv4 destination
   address.  Then M46E-PR generate whole M46E-PR address.

   Resolving source address, M46E-PR already know IPv4 network plane ID
   value and IPv6 address prefix as M46E-PR prefix.  So, searching the
   M46E-PR table does not require for resolving source address.


4.  Mode of M46E-PR

   M46E-PR has two working mode, one is router mode, another is host
   mode.

4.1.  Router mode

   In router mode, M46E-PR act as a IPv6 router.  M46E-PR occupy IPv6
   subnet, and M46E-PR advertise route for M46E-PR.

4.2.  Host mode

   In host mode, M46E-PR act as a IPv6 host.  M46E-PR share IPv4 subnet,
   that mean, M46E-PR and IPv6 hosts exists on same IPv6 subnet.
   M46E-PR do proxy NDP function for IPv4 host.






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5.  Sample configuration

   Figure Figure 6shows sample confiuration of M46E-PR.  In this
   example, there are three IPv4 stub network with the same IPv4 network
   plane.


    /------------\  /--------------------------------------/
    |            |  | Stub Network #1                      |
    |            |  |  2001:0db8:0:1::/64                  |
    |            |  | +--------+  /----------------------\ |
    |            |--| |M46E-PR |--|10.1.1.0/24(plane 1)  | |
    |            |  | +--------+  |                      | |
    |            |  |             \----------------------/ |
    |           <--[2001:0db8:0:1::/64]                    |
    |            |  /--------------------------------------/
    |            |
    |            |  /--------------------------------------/
    |            |  | Stub Network #2                      |
    |            |  |  2001:0db8:0:2::/64                  |
    | Backbone   |  | +--------+  /----------------------\ |
    | Network    |--| |M46E-PR |--|10.1.2.0/24(plane 1)  | |
    |            |  | +--------+  |                      | |
    |            |  |             \----------------------/ |
    |           <--[2001:0db8:0:2::/64]                    |
    |            |  /--------------------------------------/
    |            |
    |            |  /--------------------------------------/
    |            |  | Stub Network #3                      |
    |            |  |  2001:0db8:0:3::/64                  |
    |            |  | +--------+  /----------------------\ |
    |            |--| |M46E-PR |--|10.1.3.0/24(plane 1)  | |
    |            |  | +--------+  |                      | |
    |            |  |             \----------------------/ |
    |           <--[2001:0db8:0:3::/64]                    |
    |            |  /--------------------------------------/
    |            |
    \------------/

                                 Figure 6

   Figure Figure 7 shows M46E-PR table for sample network.









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   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46E-PR address prefix |
   +---------------------+------------+-------++-----------------------+
   |        1            | 10.1.1.0   | /120  || 2001:0db8:0:1         |
   |        1            | 10.1.2.0   | /120  || 2001:0db8:0:2         |
   |        1            | 10.1.3.0   | /120  || 2001:0db8:0:3         |
   +---------------------+------------+-------++-----------------------+

                                 Figure 7


6.  IANA Considerations

   This document makes no request of IANA.

   Note to RFC Editor: this section may be removed on publication as an
   RFC.


7.  Security Considerations

   Security Considerations does not discussed in this memo.


8.  References

8.1.  Normative References

   [I-D.draft-matsuhira-m46a]
              Matsuhira, N., "Multiple IPv4 - IPv6 mapped IPv6 address",
              August 2016.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
              RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

8.2.  Informative References













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Author's Address

   Naoki Matsuhira
   Fujitsu Limited
   17-25, Shinkamata 1-chome, Ota-ku
   Tokyo,   144-8588
   Japan

   Phone: +81-3-3730-8386
   Fax:
   Email: matsuhira@jp.fujitsu.com








































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