Mobile IPv6 Support for Dual Stack Hosts and Routers
RFC 5555

Network Working Group                                    H. Soliman, Ed.
Request for Comments: 5555                          Elevate Technologies
Category: Standards Track                                      June 2009

          Mobile IPv6 Support for Dual Stack Hosts and Routers

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (c) 2009 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 in effect on the date of
   publication of this document (http://trustee.ietf.org/license-info).
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

Abstract

   The current Mobile IPv6 and Network Mobility (NEMO) specifications
   support IPv6 only.  This specification extends those standards to
   allow the registration of IPv4 addresses and prefixes, respectively,
   and the transport of both IPv4 and IPv6 packets over the tunnel to
   the home agent.  This specification also allows the mobile node to
   roam over both IPv6 and IPv4, including the case where Network
   Address Translation is present on the path between the mobile node
   and its home agent.

Soliman                     Standards Track                     [Page 1]
RFC 5555                        DSMIPv6                        June 2009

Table of Contents

   1. Introduction ....................................................3
      1.1. Requirements Notation ......................................4
      1.2. Motivation for Using Mobile IPv6 Only ......................4
      1.3. Scenarios Considered by This Specification .................4
   2. Solution Overview ...............................................6
      2.1. Home Agent Address Discovery ...............................6
      2.2. Mobile Prefix Solicitation and Advertisement ...............7
      2.3. Binding Management .........................................8
           2.3.1. Foreign Network Supports IPv6 .......................8
           2.3.2. Foreign Network Supports IPv4 Only ..................9
      2.4. Route Optimization ........................................11
      2.5. Dynamic IPv4 Home Address Allocation ......................11
   3. Extensions and Modifications to Mobile IPv6 ....................11
      3.1. Binding Update Extensions .................................11
           3.1.1. IPv4 Home Address Option ...........................11
           3.1.2. The IPv4 Care-of Address Option ....................13
           3.1.3. The Binding Update Message Extensions ..............13
      3.2. Binding Acknowledgement Extensions ........................14
           3.2.1. IPv4 Address Acknowledgement Option ................14
           3.2.2. The NAT Detection Option ...........................16
   4. Protocol Operation .............................................17
      4.1. Tunnelling Formats ........................................17
           4.1.1. Tunnelling Impacts on Transport and MTU ............18
      4.2. NAT Detection .............................................19
      4.3. NAT Keepalives ............................................21
      4.4. Mobile Node Operation .....................................22
           4.4.1. Selecting a Care-of Address ........................22
           4.4.2. Sending Binding Updates ............................23
           4.4.3. Sending Packets from a Visited Network .............25
           4.4.4. Movement Detection in IPv4-Only Networks ...........26
      4.5. Home Agent Operation ......................................26
           4.5.1. Sending Packets to the Mobile Node .................28
      4.6. Correspondent Node Operation ..............................29
   5. Security Considerations ........................................29
      5.1. Handover Interactions for IPsec and IKE ...................30
      5.2. IKE Negotiation Messages between the Mobile Node
           and Home Agent ............................................33
           5.2.1. IKEv2 Operation for Securing DSMIPv6 Signaling .....33
           5.2.2. IKEv2 Operation for Securing Data over IPv4 ........36
   6. Protocol Constants .............................................38
   7. Acknowledgements ...............................................38
   8. IANA Considerations ............................................38