Network Working Group                                       N. Matsuhira
Internet-Draft                                           Fujitsu Limited
Intended status: Informational                              June 3, 2020
Expires: December 5, 2020


 Multiple IPv4 - IPv6 address mapping encapsulation - prefix translator
                               (M46E-PT)
                       draft-matsuhira-m46e-pt-08

Abstract

   This document specifies Multiple IPv4 - IPv6 mapping encapsulation -
   Prefix Translator (M46E-PT) specification.  M46E-PT expand IPv4
   network plane by connecting M46E-FP domain and M46E-PR domain.
   M46E-PT translate prefix part of M46E-FP address and M46E-PR address
   both are IPv6 address.  M46E-PT does not translate IPv4 packet which
   is encapsulated, so transparency of IPv4 packet is not broken.

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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   Drafts is at http://datatracker.ietf.org/drafts/current/.

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   This Internet-Draft will expire on December 5, 2020.

Copyright Notice

   Copyright (c) 2020 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



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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Basic Network Configuration  . . . . . . . . . . . . . . . . .  3
   3.  Basic function of M46E-PT  . . . . . . . . . . . . . . . . . .  4
     3.1.  Translation processing . . . . . . . . . . . . . . . . . .  5
     3.2.  M46A architecture  . . . . . . . . . . . . . . . . . . . .  5
     3.3.  Resolving translate prefix . . . . . . . . . . . . . . . .  5
     3.4.  Destination address resolution . . . . . . . . . . . . . .  6
     3.5.  Source address resolution  . . . . . . . . . . . . . . . .  6
   4.  Sample Configuration . . . . . . . . . . . . . . . . . . . . .  7
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . .  9
   7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  9
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 10
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 10
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 10























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1.  Introduction

   This document provide M46E Prefix Translator (M46E-PT) 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-FP [I-D.draft-matsuhira-m46e-fp] provide such methods.  In
   addition, M46E-PR [I-D.draft-matsuhira-m46e-pr] also provide such
   methots.  M46E-FP is backbone network based approach, on the other
   hand, M46E-PR is stub network based approach.

   M46E-PT expand IPv4 network plane by connecting M46E-FP domain and
   M46E-PR domain.  M46E-PT translate prefix part of M46E-FP address and
   M46E-PR address both are IPv6 address.  M46E-PT does not translate
   IPv4 packet which is encapsulated, so transparency of IPv4 packet is
   not broken.


2.  Basic Network Configuration

   Figure 1 shows network configuration with M46E-PT.  At large view,
   the network consists three parts, M46E-FP domain, M46E-PR domain, and
   M46E-PT.  M46E-PT connect M46E-FP domain and M46E-PR domain.





















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    <------ M46E-FP Domain ------------> <--------- M46E-PR Domain ---->

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



                                 Figure 1

   M46E-FP domain consists three parts, backbone network, stub network
   and M46E-FP.  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-FP is not needed.  M46E-FP is a backbone network based
   approach, that mean M46E-FP advertise special route for M46E-FP.

   And also, M46E-PR domain consists three parts, backbone network, stub
   network and M46E-FP.  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.  M46E-PR is a stub
   network based approach.


3.  Basic function of M46E-PT

   This section describe basic function of M46E-PT.






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3.1.  Translation processing

   M46E-PT translate between M46E-FP packet and M46E-PT packet.  M46E-FP
   packet and M46E-PT packet are almost the same, however IPv6 address
   are different.

   Fig shows packet format of M46E-FP domain and M46E-PT domain.

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

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


     /-------------------\  +----------+  /---------------------------\
     |   M46E-FP Domain  |--| M46E-PT  |--|      M46E-PR Domain       |
     |                   |  +----------+  |                           |
     \-------------------/                \---------------------------/


                                 Figure 2

3.2.  M46A architecture

   M46E-FP and M46E-PR use M46A [I-D.draft-matsuhira-m46a].

   figure Figure 3 shows M46A architecture.


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

                                 Figure 3

3.3.  Resolving translate prefix

   M46E-PT translate from M46E-FP prefix to M46E-PR prefix, or from
   M46E-PR prefix to M46E-FP prefix using M46E-FP Prefix Translation
   (M46E-PT) table. fig Figure 4shows address resolution manner and fig
   Figure 5shows M46E-PT table.






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

    \--------------------------/\--------------------------------------/
               ^                                     |
               |                                     |
               |                                     v
    +------------------------------------------------------------------+
    |                                                                  |
    |       M46E-FP Prefix Translation Table (M46E-PT Table)           |
    |                                                                  |
    +------------------------------------------------------------------+

                                 Figure 4

   M46E-FP-AT table is similar with M46E-PR table, however M46E-AT table
   may contain M46E-FP 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            |
   +---------------------+------------+-------++-----------------------+
                 :              :               :
   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46A prefix            |
   +---------------------+------------+-------++-----------------------+

                                 Figure 5

3.4.  Destination address resolution

   For address resolution for destination address, M46E-PT use M46E-PT
   table.

3.5.  Source address resolution

   For address resolution for source address, M46E-PT use interface
   information, not M46E-PT table.  From M46E-FP domain to M46E-PR
   domain, M46E-PT use IPv6 address prefix of the interface which belong
   M46E-PR domain.  From




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4.  Sample Configuration

   Figure Figure 6shows sample confiuration of M46E-PT.  In this
   example, there are four IPv4 stub network with the same IPv4 network
   plane, and two of four are in M46E-FP domain and other two of four
   are in M46E-PR domain.

   In this example, M46E-FP prefix is 2001:0db8:0:46::/64.











































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    /------------\
    |           +--------+  /----------------------\
    | Backbone  |        |  |Stub Network#1        |
    | Network   |M46E-FP |--|10.1.1.0/24(plane 1)  |
    |(IPv6 only)|        |  |2001:0db8:1:1::/64    |
    |           +--------+  \----------------------/
    |       <--[2001:0db8:1:1::/64]
    |       <--[2001:0db8:0:46:0:1:10.1.1.0/120]
    |            |
    |           +--------+  /----------------------\
    |           |        |  |Stub Network#2        |
    |           |M46E-FP |--|10.1.2.0/24(plane 1)  |
    |           |        |  |2001:0db8:1:2::/64    |
    |           +--------+  \----------------------/
    |       <--[2001:0db8:1:2::/64]
    |       <--[2001:0db8:0:46:0:1:10.1.2.0/120]
    |            |
    |       <--[2001:0db8:0:46:0:1:10.1.4.0/120]
    |       <--[2001:0db8:0:46:0:1:10.1.5.0/120]
    |           +------------+
    |           | M46E-PT   |
    |           +------------+
    \------------/    |
          |           |Stub Network #0
    /------------\    | 2001:0db8:2:0::/64
    |            |----+
    |            |  /--------------------------------------/
    |            |  | Stub Network #3                      |
    |            |  |  2001:0db8:2:1::/64                  |
    |            |  | +--------+  /----------------------\ |
    |            |--| |M46E-PR |--|10.1.3.0/24(plane 1)  | |
    |            |  | +--------+  /----------------------/ |
    |           <--[2001:0db8:2:1::/64]                    |
    |            |  /--------------------------------------/
    |            |
    |            |  /--------------------------------------/
    |            |  | Stub Network #4                      |
    |            |  |  2001:0db8:2:2::/64                  |
    | Backbone   |  | +--------+  /----------------------\ |
    | Network    |--| |M46E-PR |--|10.1.4.0/24(plane 1)  | |
    |            |  | +--------+  \----------------------/ |
    |           <--[2001:0db8:2:2::/64]                    |
    |            |  /--------------------------------------/
    \------------/


                                 Figure 6




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   Figure Figure 7 shows M46E-PT table for this example.  This example
   is default free case.

   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46E-PR address prefix |
   +---------------------+------------+-------++-----------------------+
   |        1            | 10.1.1.0   | /120  || 2001:0db8:0:46        |
   |        1            | 10.1.2.0   | /120  || 2001:0db8:0:46        |
   |        1            | 10.1.3.0   | /120  || 2001:0db8:2:1         |
   |        1            | 10.1.4.0   | /120  || 2001:0db8:2:2         |
   +---------------------+------------+-------++-----------------------+

                                 Figure 7

   Fig Figure 8shows another M46E-PT table for this example.  This
   example use default for M46E-FP.  If there are many stub network in
   M46E-FP domain, by using default as M46E-FP prefix, reduction of
   M46E-PT table size can be possible.

   +---------------------+------------+-------++-----------------------+
   |IPv4 network plane ID|IPv4 address|netmask||M46E-PR address prefix |
   +---------------------+------------+-------++-----------------------+
   |        1            | 10.1.3.0   | /120  || 2001:0db8:2:1         |
   |        1            | 10.1.4.0   | /120  || 2001:0db8:2:2         |
   |        1            |  0.0.0.0   | /0    || 2001:0db8:0:46        |
   +---------------------+------------+-------++-----------------------+

                                 Figure 8


5.  IANA Considerations

   This document makes no request of IANA.

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


6.  Security Considerations

   Security Considerations does not discussed in this memo.


7.  Acknowledgements


8.  References




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8.1.  Normative References

   [I-D.draft-matsuhira-m46a]
              Matsuhira, N., "Multiple IPv4 - IPv6 mapped IPv6 address",
              June 2019.

   [I-D.draft-matsuhira-m46e-fp]
              Matsuhira, N., "Multiple IPv4 - IPv6 address mapping
              encapsulation - fixed prefix (M46E-FP)", June 2019.

   [I-D.draft-matsuhira-m46e-pr]
              Matsuhira, N., "Multiple IPv4 - IPv6 address mapping
              encapsulation - prefix resolution", June 2019.

   [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


Author's Address

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

   Phone: +81-3-3735-1111
   Fax:
   Email: matsuhira@jp.fujitsu.com


















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