Internet DRAFT - draft-chelius-adhoc-ipv6
draft-chelius-adhoc-ipv6
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.
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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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