Internet Engineering Task Force (IETF)                     S. Gundavelli
Request for Comments: 6543                                         Cisco
Updates: 5213                                                   May 2012
Category: Standards Track
ISSN: 2070-1721


        Reserved IPv6 Interface Identifier for Proxy Mobile IPv6

Abstract

   Proxy Mobile IPv6 (RFC 5213) requires that all mobile access gateways
   use a fixed link-local address and a fixed link-layer address on any
   of their access links that they share with mobile nodes.  This
   requirement was intended to ensure that a mobile node does not detect
   any change with respect to its Layer 3 attachment, even after it
   roams from one mobile access gateway to another.  In the absence of
   any reserved addresses for this use, coordination across vendors and
   manual configuration of these addresses on all of the mobility
   elements in a Proxy Mobile IPv6 domain are required.  This document
   attempts to simplify this operational requirement by making a
   reservation for special addresses that can be used for this purpose.
   This document also updates RFC 5213.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6543.

Copyright Notice

   Copyright (c) 2012 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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   carefully, as they describe your rights and restrictions with respect
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   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. Conventions and Terminology .....................................3
      2.1. Conventions ................................................3
      2.2. Terminology ................................................3
   3. IANA Considerations .............................................4
   4. Security Considerations .........................................4
   5. Acknowledgements ................................................4
   6. References ......................................................5
      6.1. Normative References .......................................5
      6.2. Informative References .....................................5

1.  Introduction

   Proxy Mobile IPv6 [RFC5213] is a network-based mobility management
   protocol that enables IP mobility support for a mobile node without
   requiring its participation in any mobility-related signaling.  The
   mobility elements in the network ensure that the mobile node does not
   detect any change with respect to its Layer 3 attachment, even after
   it roams from one mobile access gateway to another and changes its
   point of attachment in the network.  All mobile access gateways in a
   Proxy Mobile IPv6 domain use a fixed link-local address and a fixed
   link-layer address on any of their access links that they share with
   the mobile nodes.  This essentially ensures that a mobile node, after
   performing a handoff, does not detect any change with respect to the
   IP network configuration.

   Although the base Proxy Mobile IPv6 specification [RFC5213] requires
   the use of a fixed link-local and a fixed link-layer address, it did
   not reserve any specific addresses for this purpose.  This is proving
   to be an operational challenge in deployments involving multi-vendor
   equipment.  To address this problem, this specification makes the
   following two reservations.

   1.  This specification reserves one Ethernet unicast address,
       00-00-5E-00-52-13, for use with Proxy Mobile IPv6.  This reserved
       link-layer address SHOULD be used by the mobile access gateway in
       a Proxy Mobile IPv6 domain, on all of the access links that it
       shares with the mobile nodes.  The protocol configuration
       variable FixedMAGLinkLayerAddressOnAllAccessLinks [RFC5213]
       SHOULD be set to this reserved address.  The mobile access
       gateway can use this address in all packet communication with the
       mobile node on the access links.  Considerations from [RFC5342]
       apply with respect to the use of Ethernet parameters in IETF
       protocols.  This address is allocated from the registry "IANA
       Ethernet Address Block - Unicast Use".

   2.  This specification reserves an IPv6 interface identifier,
       0200:5EFF:FE00:5213.  This interface identifier is a modified
       EUI-64 interface identifier generated from the allocated Ethernet
       unicast address 00-00-5E-00-52-13.  This reserved IPv6 interface
       identifier SHOULD be used by all of the mobile access gateways in
       a Proxy Mobile IPv6 domain on all of the access links that they
       share with the mobile nodes.  The protocol configuration variable
       FixedMAGLinkLocalAddressOnAllAccessLinks [RFC5213] SHOULD be set
       to the link-local address generated using this reserved IPv6
       interface identifier.  The mobile access gateway can use this
       link-local address generated using this reserved IPv6 interface
       identifier in all Neighbor Discovery-related [RFC4861]
       communication with the mobile node.

2.  Conventions and Terminology

2.1.  Conventions

   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].

2.2.  Terminology

   All of the mobility-related terms used in this document are to be
   interpreted as defined in the base Proxy Mobile IPv6 specifications
   ([RFC5213], [RFC5844]).  All of the terminology related to IPv6
   addressing is to be interpreted as specified in [RFC4291].

3.  IANA Considerations

   o  This specification reserves one Ethernet unicast address,
      00-00-5E-00-52-13, for Proxy Mobile IPv6.  This address has been
      reserved in the registry "IANA Ethernet Address Block - Unicast
      Use".

   o  This specification reserves an IPv6 interface identifier,
      0200:5EFF:FE00:5213, for Proxy Mobile IPv6 [RFC5213] in the
      registry "Reserved IPv6 Interface Identifiers" [RFC5453].  This
      interface identifier is a modified EUI-64 interface identifier
      generated from the allocated Ethernet unicast address
      00-00-5E-00-52-13, as specified in Appendix A of [RFC4291].

4.  Security Considerations

   All of the security considerations specified in [RFC5213] and
   [RFC5844] continue to apply to the mobility elements in a Proxy
   Mobile IPv6 domain when those elements conform to this specification.
   Specifically, the issues related to the use of fixed link-local and
   link-layer addresses as documented in Section 6.9.3 of the base Proxy
   Mobile IPv6 specification are equally relevant here.  In some sense,
   the reservations made in this specification result in the use of the
   same set of link-local and link-layer address values beyond a single
   Proxy Mobile IPv6 domain, thereby expanding the scope of the existing
   problem related to asserting ownership of the configured addresses
   from a single domain to a multi-domain environment.  Future work may
   be needed to address these issues.

5.  Acknowledgements

   The author would like to thank Jari Arkko and Dave Thaler for all of
   the discussions around the use of fixed link-local and link-layer
   addresses during work related to the standardization of Proxy Mobile
   IPv6 [RFC5213].  The author would also like to thank Tero Kivinen,
   Donald Eastlake 3rd, Stephen Farrell, Suresh Krishnan, Margaret
   Wasserman, Thomas Narten, Basavaraj Patil, and Eric Voit for their
   reviews and participation in the discussions related to this
   document.

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, February 2006.

   [RFC5213]  Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
              Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
              RFC 5213, August 2008.

   [RFC5453]  Krishnan, S., "Reserved IPv6 Interface Identifiers",
              RFC 5453, February 2009.

6.2.  Informative References

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC5342]  Eastlake 3rd, D., "IANA Considerations and IETF Protocol
              Usage for IEEE 802 Parameters", BCP 141, RFC 5342,
              September 2008.

   [RFC5844]  Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
              Mobile IPv6", RFC 5844, May 2010.

Author's Address

   Sri Gundavelli
   Cisco
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   EMail: sgundave@cisco.com