Network Working Group                                       T. Mrugalski
Internet-Draft                           Gdansk University of Technology
Intended status: Standards Track                           July 05, 2010
Expires: January 6, 2011


             DHCPv6 Server side Duplicate Address Detection
                  draft-mrugalski-server-dad-dhcpv6-00

Abstract

   This document defines new way of performing DAD procedure.  DHCPv6
   maintain small pool of unique addresses.  DHCPv6 server performs DAD
   procedure for each address, before populating this uniqueness
   verified pool.  Client may ask for an address that already passed DAD
   test, thus speeding up client configuration process.

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
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   This Internet-Draft will expire on January 6, 2011.

Copyright Notice

   Copyright (c) 2010 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
   (http://trustee.ietf.org/license-info) in effect on the date of



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   publication of this document.  Please review these documents
   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  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Server Side DAD Option Format . . . . . . . . . . . . . . . . . 3
   3.  DHCPv6 Server Behavior  . . . . . . . . . . . . . . . . . . . . 3
   4.  DHCPv6 Client Behavior  . . . . . . . . . . . . . . . . . . . . 4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   7.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 4

































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1.  Introduction

   Once Mobile Node (MN) attaches to a new link, it obtains new IPv6
   address, using DHCPv6 protocol.  Once DHCPv6 exchange is concluded,
   MN determines address uniqueness using Duplicate Address Detection
   (DAD) procedure.  Such procedure introduces unwanted delays that are
   expecially problematic in mobile environments.  This document defines
   new way of performing DAD procedure.  DHCPv6 maintain small pool of
   unique addresses.  DHCPv6 server performs DAD procedure for each
   address, before populating this uniqueness verified pool.  Client may
   ask for address that already passed DAD test.


2.  Server Side DAD Option Format

   A DHCPv6 server may provide addresses that have already passed DAD
   tests.
      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    OPTION_SERVER_SIDE_DAD     |          option-len           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 1: DAD Address Option Format

   option-code:  OPTION_SERVER_SIDE_DAD (TBD).

   option-len:  0 (there are no fields in this option).


3.  DHCPv6 Server Behavior

   Server MUST complete DAD procedure, as specifed in [RFC4861], for
   each address included in DAD-verified pool.

   Server MUST NOT provide address that did not complete DAD procedure
   to client that requests DAD-verified address.

   Server SHOULD maintain separate pool for clients that request DAD-
   verified addresses.

   Server MUST include OPTION_SERVER_SIDE_DAD in the IA_NA option that
   was populated to indicate that provided address is indeed DAD-
   verified.







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4.  DHCPv6 Client Behavior

   Client supporting server side DAD, MAY include OPTION_SERVER_SIDE_DAD
   in their IA_NA option to indicate that DAD-verified address is
   requested.

   TBD


5.  IANA Considerations

   IANA is requested to allocate one DHCP option codes referencing this
   document: OPTION_SERVER_SIDE_DAD.


6.  Security Considerations

   TBD


7.  Normative References

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

   [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.

   [RFC3775]  Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
              in IPv6", RFC 3775, June 2004.

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


Author's Address

   Tomasz Mrugalski
   Gdansk University of Technology
   Storczykowa 22B/12
   Gdansk  80-177
   Poland

   Phone: +48 698 088 272
   Email: tomasz.mrugalski@eti.pg.gda.pl




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