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Versions: 00                                                            
Internet Draft                                               G. Chelius
Document: draft-chelius-adhoc-ipv6-00.txt                     E. Fleury
Expires: March 2003                                         Ares, Inria
                                                         September 2002


      IPv6 Addressing Architecture Support for mobile ad hoc networks
                     <draft-chelius-adhoc-ipv6-00.txt>


Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of rfc-2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other documents
   at any time.  It is inappropriate to use Internet-Drafts as
   reference material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
        http://www.ietf.org/ietf/1id-abstracts.txt
   The list of Internet-Draft Shadow Directories can be accessed at
        http://www.ietf.org/shadow.html.


Abstract

   The concept of node identifier, in practical terms an IP address, is
   crucial in ad hoc networks. Its use allows the setup of IP routing
   for ad hoc connectivity and the identification of several wireless
   devices as part of a unique ad hoc node. In this document, a new
   addressable object is defined: the ad hoc connector. It virtualizes
   several ad hoc network interfaces into a single addressable object.
   To locally address ad hoc connectors, a third IPv6 local-use unicast
   address (adhoc-local address) and the correlated use of the subnet
   multicast scope are defined.


Table of Contents

   Status of this Memo................................................1
   Abstract...........................................................1
   1. Introduction....................................................3
   2. Terminology.....................................................3
   3. Ad hoc connector................................................4
   3.1 Ad hoc connector management....................................4
   3.2 Interface binding..............................................5

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   4. Addressing an ad hoc connector..................................5
   4.1 Local addressing...............................................5
   4.2 Global addressing..............................................6
   5. Addressing multiple ad hoc connectors...........................6
   5.1 Predefined ad hoc multicast addresses..........................6
   5.2 Multicast and ad hoc sub-networks..............................7
   5.3 Multicast membership...........................................8
   6. Duplicated ad hoc address detection.............................8
   7. Global Prefix Discovery.........................................8
   8. Security Considerations.........................................8
   9. Notes...........................................................9
   References........................................................10
   Author's Addresses................................................10








































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1. Introduction

   The notion of ad hoc network is something particular compared to
   classical network architectures. It is a logical view that unifies
   several physical networks in a single multigraph topology. As said
   in [rfc2501], the concept of a "node identifier", in practical terms
   an IP address, is crucial in ad hoc networks. Its use allows the
   setup of IP routing for ad hoc connectivity as well as the
   identification of several wireless devices as part of a unique ad
   hoc node.

   To gather several ad hoc interfaces in a single entity, the notion
   of ad hoc connectors is introduced. The ad hoc connector is the
   basic element of ad hoc networks. It virtualizes several network
   interfaces into a single addressable object. A host may have several
   ad hoc connectors and an interface may be bound to several ad hoc
   connectors. The ad hoc connector defines a set of addresses which
   identify indistinctly all bounded interfaces.

   IPv6 addressing architecture proposes two local unicast addresses
   and their equivalent multicast scope: link-local and site-local. The
   use of link-local unicast and multicast addresses is unsuitable to
   ad hoc networks. A link-Local unicast address refers to a single
   interface and its validity is limited to the interface link.
   Since an ad hoc network may be included in a larger site or spread
   over different sites, a specific ad hoc use of site-local addresses
   is also inappropriate. In addition, a site-local address identifies
   a single interface whereas an ad hoc address may identify several
   ones.

   To locally address ad hoc connectors, we propose the definition of a
   third IPv6 local-use unicast address: adhoc-local addresses. Their
   validity is limited to an ad hoc network. They provide a basic
   identification support for ad hoc nodes that can be extended by
   other configuration mechanisms such as stateless global address
   attribution.

   In the IPv6 architecture scheme, an ad hoc network may be at the
   same time, a multi-link subnet and a multi-link multi-subnet.
   Considering the whole ad hoc network as a multi-link subnet is
   achieved by matching a particular multicast scope, the subnet scope,
   with the ad hoc network. To support the multi-link multi-subnet
   vision, the notion of logical ad hoc sub-networks, also called
   channels, is introduced. A channel is a connex set of ad hoc
   connectors sharing a common channel value. A specific range of
   multicast addresses is associated to each channel. It enables the
   restriction of multicast groups to a given channel.


2. Terminology

   Ad hoc connector    - the basic element of an ad hoc network. It
                         virtualizes several network interfaces in a

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                         single addressable object.

   Ad hoc identifier   - a 64bits value that pseudo-uniquely identifies
                         an ad hoc connector.

   Ad hoc channel      - a non null 16bits value associated to an ad
                         hoc connector. This value indicates the ad hoc
                         sub-network the ad hoc connector is connected
                         to.

   Ad hoc interface    - a network interface bound to an ad hoc
                         connector.

   Ad hoc host         - a host with at least one ad hoc interface.

   Ad hoc route        - a network route that only transits through ad
                         hoc interfaces.

   Ad hoc network      - a maximal and connex set of ad hoc connectors.

   Ad hoc sub-network  - a maximal and connex set of ad hoc connectors
                         sharing a common channel value.

   Ad hoc router       - an ad hoc node which may route packets between
                         ad hoc network(s) and non ad hoc network(s).

   Ad hoc sub-router   - an ad hoc node which may route packets between
                         two or more ad hoc sub-networks.


   All ad hoc nodes must be configured as IPv6 unicast and multicast
   routers.

   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].


3. Ad hoc connector

   As defined in [rfc2501], a MANet is the *union* of physical-layer
   multihop topologies, i.e. a multigraph. In this multigraph, it is
   inappropriate to use the network interface as the basic addressable
   element; network interfaces only exist in one single physical layer
   topology. The ad hoc connector is defined as the basic element of ad
   hoc networks. It is a view of mind that virtualizes several network
   interfaces into a single addressable object.


3.1 Ad hoc connector management




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   In the network, an ad hoc connector is identified by a 64bits value,
   the ad hoc identifier. Another 16bits non null value is associated
   to the connector: its ad hoc channel value.

   Ad hoc connectors are created and destroyed by user management. Ad
   hoc IDs and ad hoc channel values are provided by the user at the
   connector creation. The ad hoc channel may be changed during the ad
   hoc connector life. A host may have several ad hoc connectors.
   However, ad hoc connectors of a single host must have different
   identifiers and different channel values.

   For the ad hoc network to correctly behave, it is preferred for ad
   hoc IDs to be unique. It is the user responsibility to ensure
   uniqueness of its IDs. To build pseudo-unique IDs, host interface
   MAC addresses or cryptographic mechanisms such as the one described
   in [SUCV] may be used.


3.2 Interface binding

   Network interfaces are manually bound to and unbound from ad hoc
   connectors by user management. A network interface may be bound to
   several ad hoc connectors and several network interfaces may be
   bound to a same ad hoc connector.


4. Addressing an ad hoc connector

   An ad hoc connector is associated to a set of IPv6 addresses which
   identify all bounded addresses. These addresses are an adhoc-local
   address and eventually one or more global addresses. The local
   address ensures connectivity in the ad hoc network and the global
   ones enable Internet connectivity.


4.1 Local addressing

   To address an ad hoc connector inside an ad hoc network, we define a
   third type of local-use unicast address: adhoc-local. The adhoc-
   local scope is for use in a single adhoc network. It is valid in all
   ad hoc sub-networks of the ad hoc network. Adhoc-Local addresses
   have the following format:


   |    10    |                         |                            |
   |   bits   |        54 bits          |         64 bits            |
   +----------+-------------------------+----------------------------+
   |1111111001|            0            |    ad hoc connector ID     |
   +----------+-------------------------+----------------------------+



   Each ad hoc connector is associated to a single adhoc-local address
   constructed using its identifier.

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   Ad Hoc nodes must not forward any packet with adhoc-local source or
   destination through a non ad hoc interface.

   In addition to addresses given in [rfc2373], an ad hoc interface is
   required to recognize the following addresses as identifying itself:

        o adhoc-local addresses of all ad hoc connectors it is bounded
          to.

   An ad hoc interface is required to join the solicited-node multicast
   groups associated to the following unicast addresses:

        o adhoc-local addresses of all ad hoc connectors it is bounded
          to.


4.2 Global addressing

   Ad hoc connectors may be addressed using global addresses if global
   prefixes are available in the ad hoc network.

   If a given global prefix P is delivered to an ad hoc connector with
   identifier Id, the global address constructed by concatenation of P
   and Id is associated to the ad hoc connector

   An ad hoc interface is required to recognize the following addresses
   as identifying itself:

        o all global addresses associated to all ad hoc connectors it
          is bounded to.

   An ad hoc interface is required to join the solicited-node multicast
   groups associated to the following unicast addresses:

        o all global addresses associated to all ad hoc connectors it
          is bounded to.


5. Addressing multiple ad hoc connectors

   To address multiple ad hoc connectors and to limit the scope of a
   multicast group to an ad hoc network, we use the subnet multicast
   scope as defined in [IPV6ADDR].


5.1 Predefined ad hoc multicast addresses

   In addition to the ones given in [IPV6ADDR], the following well-
   known ad hoc multicast addresses are predefined:

   "All ad hoc nodes" address:
                       FF03:0:0:0:0:0:0:1


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   The above multicast address identifies the group of all IPv6 ad hoc
   nodes within the ad hoc network.

   "All ad hoc routers" address:
                       FF03:0:0:0:0:0:0:A

   The above multicast address identifies the group of all IPv6 ad hoc
   routers within the ad hoc network.

   "All ad hoc sub-routers" address:
                       FF03:0:0:0:0:0:0:B

   The above multicast address identifies the group of all IPv6 ad hoc
   sub-routers within the ad hoc network.

   Ad Hoc nodes must not forward any multicast packet with subnet scope
   through a non ad hoc interface.


5.2 Multicast and ad hoc sub-networks

   To address multiple ad hoc connectors inside a single ad hoc sub-
   network and to limit the scope of a multicast group to an ad hoc
   sub-network, we define a range of multicast addresses:
                       FF03:0:0:channel value:0:0:0:0

   For a given channel value X, the following well-known ad hoc
   multicast addresses are predefined:

   Reserved Multicast Address:
                       FF03:0:0:X:0:0:0:0

   The above multicast address is reserved and shall never be assigned
   to any multicast group.

   "All ad hoc nodes of a sub-network" address:
                       FF03:0:0:X:0:0:0:1

   The above multicast address identifies the group of all IPv6 nodes
   within the ad hoc sub-network.

   "All ad hoc routers of a sub-network" address:
                       FF03:0:0:X:0:0:0:A

   The above multicast address identifies the group of all IPv6 ad hoc
   routers within the ad hoc sub-network.

   "All ad hoc sub-routers of a sub-network" address:
                       FF03:0:0:X:0:0:0:B

   The above multicast address identifies the group of all IPv6 ad hoc
   sub-routers within the ad hoc sub-network.



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   Ad Hoc nodes must not forward any multicast packet limited to an ad
   hoc sub-network with channel value X through an interface that is
   not connected to an ad hoc connector with channel value X.


5.3 Multicast membership

   Ad hoc interfaces must join the following multicast groups:

        o "All ad hoc nodes"
        o "All ad hoc nodes of a sub-network" for the channel values of
          the ad hoc connectors they are bounded to.

   In addition, ad hoc interfaces of ad hoc routers must join the
   following groups:

        o "All ad hoc routers"
        o "All ad hoc routers of a sub-network" for the channel
          values of the ad hoc connectors they are bounded to.

   In addition, ad hoc interfaces of ad hoc sub-routers must join the
   following groups:

        o "All ad hoc sub-routers"
        o "All ad hoc sub-routers of a sub-network" for the channel
          values of the ad hoc connectors they are bounded to.


6. Duplicated ad hoc address detection

   Ad hoc specific Duplicated Address Detection (DAD) may be performed
   once or several times, eventually periodically, on ad hoc addresses.
   Ad hoc specific DAD is not mandatory since it is not safe.

   It is an ad hoc node responsibility to ensure uniqueness of its ad
   hoc addresses; either using an ad hoc specific DAD, either using
   unique or pseudo-unique ad hoc connector identifiers.

   Classical DAD protocols are inappropriate in the ad hoc environment.
   Definition of an appropriate protocol is behind the scope of this
   document. An example is given in [AUTOCONF].


7. Global Prefix Discovery

   Global prefixes may be manually or automatically delivered to ad hoc
   connectors. Definition of an ad hoc specific Prefix Discovery
   Protocol is behind the scope of this document. An example is given
   in [CONNECT].


8. Security Considerations



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   IPv6 addressing documents do not have any direct impact on Internet
   infrastructure security. Authentication of IPv6 packets is defined
   in [AUTH].

   This document does not modify security issues related to ad hoc
   networks.


9. Notes

   Values of the adhoc-local unicast prefix and predefined multicast
   addresses are given as examples and are not restrictive. Addresses
   and prefixes must be attributed by the IANA.










































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References

   [AUTH]    Atkinson, R., "IP Authentication Header", RFC 1826, August
   1995.

   [rfc2373] Hinden, R. and Deering, S., "IP Version 6 Addressing
   Architecture", RFC 2373, July 1998.

   [rfc2461] Narten, T. and Nordmark, E. and Simpson, W., "Neighbor
   Discovery for IP version 6 (IPv6)", RFC 2461, December 1998.

   [rfc2501] Corson, S. and Macker, J., "Mobile Ad hoc Networking
   (MANET): Routing Protocol Performance Issues and Evaluation
   Considerations", RFC 2501, January 1999.

   [AUTOCONF]   Perkins, C. and Malinen, J. and Wakikawa, R. and
   Belding-Royer, E. And Sun, Y., "IP Address Autoconfiguration for Ad
   Hoc Networks", Internet draft, draft-ietf-manet-autoconf-01.txt.

   [SUCV]    Montenegro, G. and Castelluccia, C., "SUCV Identifiers and
   Addresses", Internet draft, draft-montenegro-sucv-02.txt.

   [IPV6ADDR]  Hinden, R. and Deering, S., "IP Version 6 Addressing
   Architecture", Internet draft, draft-ietf-ipngwg-addr-arch-v3-
   08.txt.

   [CONNECT] Wakikawa, R. and Malinen, J. and Perkins, C. and Nilsson,
   A. and Tuominen, A., "Global connectivity for IPv6 Mobile Ad Hoc
   Networks", Internet draft, draft-wakikawa-manet-globalv6-01.txt.


Author's Addresses

   Guillaume Chelius
   Ares, Inria
   Batiment Leonard de Vinci
   21 avenue Jean Capelle
   69621 Villeurbanne Cedex
   France
   Email:  gchelius@telecom.insa-lyon.fr

   Eric Fleury
   Ares, Inria
   Batiment Leonard de Vinci
   21 avenue Jean Capelle
   69621 Villeurbanne Cedex
   France
   Email: Eric.Fleury@inria.fr







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