IPv6 Maintenance                                                T. Chown
Internet-Draft                                 University of Southampton
Intended status: Informational                          October 22, 2012
Expires: April 25, 2013


                       Tokenised IPv6 Identifiers
             draft-chown-6man-tokenised-ipv6-identifiers-02

Abstract

   This text is intended to open discussion towards the adoption of
   support for tokenised IPv6 interface identifiers in IPv6 nodes.  The
   primary target for such support is server platforms where addresses
   are usually manually configured, rather than using DHCPv6 or SLAAC.
   By using tokenised identifiers, hosts can still determine their
   network prefix by use of SLAAC, but more readily be automatically
   renumbered should their network prefix change.

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   This Internet-Draft will expire on April 25, 2013.

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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   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Tokenised IPv6 identifier support . . . . . . . . . . . . . . . 3
   3.  On the static address problem . . . . . . . . . . . . . . . . . 3
   4.  Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
   8.  Informative References  . . . . . . . . . . . . . . . . . . . . 4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 5




































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1.  Introduction

   The usual choices for IPv6 nodes to obtain addresses are Stateless
   Address Autoconfiguration (SLAAC) [RFC4862], DHCPv6 [RFC3315], or
   manual configuration.  Client devices generally use SLAAC or DHCPv6.
   In the case of server systems, interface addresses are typically both
   static and manually configured.  SLAAC is not used in case the
   interface hardware changes and the associated SLAAC generated address
   changes with it.  DHCPv6 is often not used due to concerns of server
   stability should DHCPv6 fail.

   The disadvantage with static addresses is that they are likely to
   require manual editing should the network prefix in use change.  If
   instead there were a method to only manually configure the static
   identifier part of the IPv6 address, then the address could be
   automatically updated when a new prefix was introduced, as described
   in [RFC4192] for example.  In such cases a DNS server might be
   configured with such a tokenised interface identifier of ::53, and
   SLAAC would use the token in constructing the interface address,
   using the advertised prefix.


2.  Tokenised IPv6 identifier support

   The author is aware of support for tokenised IPv6 identifiers in
   Solaris, and of a proof of concept implementation for Linux.

   Under Solaris, tokenised identifiers can be configured directly with
   ifconfig, e.g.

   ifconfig qfe0 inet6 token ::53/64

   or the configuration can be made persistent by adding a line to the
   appropriate /etc/hostname6.interface file.

   In the Linux proof of concept implementation [Thompson05], a command
   line can be used to configure the interface:

   ip6token eth0 ::53

   The specifics of how such tokenised identifiers are configured are
   likely to be operating system dependent.  The important point is that
   such identifier configuration should be supported.


3.  On the static address problem

   This approach would address in part the problems discussed in



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   [I-D.ietf-6renum-static-problem] in Sections 2.3 and 2.8, for the
   address configuration of server systems.

   While a broader solution for the management of static addresses is
   desirable, tokenised identifiers present a useful interim step, if
   vendors choose to support the concept.


4.  Conclusions

   It would be desirable if all potential IPv6 server platforms
   supported tokenised interface identifiers.  There may also be
   benefits for other IPv6 nodes to do so.

   The author welcomes feedback on this draft, and any comments on
   platforms currently supporting such identifier configuration, or any
   reasons why wider implementation should not be considered.


5.  Security Considerations

   There are no extra security consideration for this document.


6.  IANA Considerations

   There are no extra IANA consideration for this document.


7.  Acknowledgments

   The author thanks the 6NET project under which considerations of
   tokenised identifiers was originally made, and colleague (at the
   time) Mark Thompson for his proof of concept implementation of such
   identifiers on a Linux platform.


8.  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.

   [RFC4192]  Baker, F., Lear, E., and R. Droms, "Procedures for
              Renumbering an IPv6 Network without a Flag Day", RFC 4192,
              September 2005.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless



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              Address Autoconfiguration", RFC 4862, September 2007.

   [I-D.ietf-6renum-static-problem]
              Carpenter, B. and S. Jiang, "Problem Statement for
              Renumbering IPv6 Hosts with Static Addresses",
              draft-ietf-6renum-static-problem-02 (work in progress),
              September 2012.

   [Thompson05]
              Thompson, M., "Introducing IPv6 Tokenised Interface
              Identifiers into the Linux Kernel", 2005, <http://
              eprints.ecs.soton.ac.uk/11045/1/tokenisedlinux.pdf>.


Author's Address

   Tim Chown
   University of Southampton
   Highfield
   Southampton, Hampshire  SO17 1BJ
   United Kingdom

   Email: tjc@ecs.soton.ac.uk




























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