autoconf Working Group Jaehwoon Lee
Internet Draft Dongguk University
Expires: August 17, 2009 Sanghynn Ahn
University of Seoul
Younghan Kim
Soongsil University
Yuseon Kim
Sangeon Kim
KT
Febraury 18, 2009
DHCP options for MANET prefix in connected MANET
draft-jaehwoon-autoconf-dhcpoption-00.txt
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Abstract
The mobile ad hoc network (MANET) is a wireless network composed of
mobile nodes which can communicate with each other via multiple
wireless links. The modified MANET architecture is now standardizing
that can resolve the multi-link subnet issue. In this draft, we
define two DHCP options in order that a MANET Router (MR) gets the
network prefix assigned to the connected MANET. The one is the MANET
prefix request option used by a MR when it wants to know the network
presix allocated to the MANET. The other is the MANET prefix option
that DHCP server provides the MANET prefix to the requesting MR.
Table of Contents
1. Introduction..................................................3
2. Terminology...................................................4
3. DHCP option format............................................4
3.1 MANET prefix Request option...............................4
3.2 MANET prefix option.......................................4
4. Option usage..................................................5
5. Security Considerations.......................................6
6. IANA Considerations...........................................6
References.......................................................7
Author's Addresses...............................................7
Intellectual Property and Copyright Statements ..................9
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1. Introduction
The Mobile Ad hoc Network (MANET) is a wireless network composed of
mobile nodes which can communicate with each other via multiple
wireless links[1]. When two nodes not within their transmission range
want to communicate, they have to communicate via wireless multiple
hops. Thus a routing mechanism that can determine an end-to-end
multi-hop wireless route between two nodes is required. However, it
is also important an address auto-configuration mechanism that a node
can automatically configure its address by itself.
From the extenal connectivity point of view, the MANET can be
classified into the standalone MANET and the connected MANET[2].
Standalone MANET is the MANET not connected to the global Internet.
On the other hand, the connected MANET is the MANET connected to the
global Internet by using the MANET border router (MBR). In the
connected MANET, one communicating with an end host is a MANET node
and the other end can be a MANET node within the same MANET or a host
within the Internet. Nodes in a connected MANET should be allocated
with Internet topologically correct global IP addresses.
Previous researches on the MANET have considered an MANET as a single
subnetwork, so all nodes in a MANET are assigned the same subnet
prefix, which is the multi-link subnet model. Recently, an Internet
document considering the issues that can occur in a multi-link subnet
was standardized[3]. In accordance with the documnet, the modified
MANET architecture that defines a MANET node (MN) as a composite of
one MANET router (MR) and zero or more hosts is currently on the
standardization process[4]. That is, a MANET is defined as a network
composed of multiple MRs connected via wireless links. An MR should
know the network prefix allocated to the MANET that it is connected.
However, till now there is no method to define how to know the
MANET's network prefix.
In this draft, we define the DHCP options for an MR to get network
prefix allocated to the connected MANET.
2. Terminology
MANET Prefix The network prefix assigned to the connected MANET
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3. Option Format
3.1 DHCP option for MANET prefix request
The option is used to request the network prefix assigned to the
MANET. The format of the MANET prefix request option is:
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 code | Option length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DHCP option Fields:
Option code TBD (MANET Prefix Request)
Option length 4
3.2 DHCP option for MANET prefix
The option is used to provide the network prefix assigned to the
MANET. The format of the MANET prefix option is:
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 code | Option length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix length | |
+-+-+-+-+-+-+-+-+ |
| MANET Prefix |
| (16 octets) |
| |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+
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DHCP option Fields:
Option code TBD (MANET Prefix)
Option length 17
Prefix length Length for the MANET prefix in bits
MANET prefix Network prefix assigned to the MANET
4. Option usage
+--------------+
/ \ +----+
+ Internet +-----+Host+
\ / +----+
+-------+------+
|
+-+-+ (Mobile Ad Hoc Network)
+-----------------+MBR+-------------------------------------------+
| +-+-+ MANET Prefix: 2008:1234::/32 |
| | +------+ |
| | +---+Host11| |
| +-+-+ | +------+ |
| |MR1+--------------------------+ |
| +-+-+ | +------+ |
| | +---+Host12| |
| | +------+ |
| | Network prefix for MR1's IP interface: |
| | 2008:1234:5678:9ABC::/64 |
| | +------+ |
| | +---+Host21| |
| +-+-+ | +------+ |
| |MR2+--------------------------+ |
| +-+-+ | +------+ |
| +---+Host22| |
| +------+ |
| Network prefix for MR2's IP interface: |
| 2008:1234:5678:9ABD::/64 |
+-----------------------------------------------------------------+
Figure 1. An example of address configuration in the MANET
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Figure 1 shows an address autoconfiguration example of a MANET based
on the modified MANET architecture. An MR has two types of
interfaces, one or more MANET interfaces and zero or more IP
interfaces. The MANET interface is used to communicate with other MRs
and the IP interface is connected to the hosts. The MANET and the
IP interfaces should be allocated with different network prefixes.
How to assign a network prefix to a MANET interface is out of the
scope of this draft. One possible method is to use the scope-extended
Router Advertisement (SERA) ICMP message[5]. Moreover, different IP
interfaces should be allocated with different network prefixes. How
to assign a network prefix to an IP interface is out of the scope of
this draft. One possible method is to use the DHCP prefix option[6].
The network prefixes allocated to IP interfaces should be subset of
the network prefix allocated to the MANET, that is, MANET prefix.
How an MR gets the MANET prefix is described in this draft.
An MR send an DHCP request message containing MANET prefix request
option in order to get the network prefix allocated to the MANET.
The option format is defined in Section 3.1. The DHCP server sends a
DHCP reply message including the MANET prefix option containing the
MANET prefix in response to the MANET prefix request option. The
option format for the MANET prefix option is defined in Section 3.2.
How to use the MANET prefix by an MR is out of the scope of this
draft. One possibility is that an MR within an MANET can decide
whether the destination host resides in the same MANET based on the
destination address of the received IP packet.
5. Security Consideration
TBD.
6. IANA Considerations
TBD.
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References
[1] C. Perkins, Ad Hoc Networking, Addison Wesley, 2001.
[2] C. Bernardos, M. Calderon and H. Moustafa, "Survey of IP address
autoconfiguration mechanisms for MANETs",
draft-bernardos-manet-autoconf-survey-04, work in progress,
Nov. 2008.
[3] D. Thaler, "Multi-Link Subnet Issues", RFC 4903, June 2007.
[4] I. Chakeres, J. Macker and T. Clausen, "Mobile Ad hoc Network
Architecture", draft-ietf-autoconf-manetarch-07,
Work in progress, Nov. 2007.
[5] J. Lee, S. Ahn, Y. Kim, Y. Kim and S. Kim, "Scope-extended router
advertisement for connected MANETs",
draft-jaehwoon-autoconf-sera-01, work in progress, Oct. 2008.
[6] O. Troan and R. Droms, "IPv6 Prefix Options for Dynamic Host
Configuration Protocol (DHCP) version 6", RFC 3633, Dec. 2003.
Author's Addresses
Jaehwoon Lee
Dongguk University
26, 3-ga Pil-dong, Chung-gu
Seoul 100-715, KOREA
Email: jaehwoon@dongguk.edu
Sanghyun Ahn
University of Seoul
90, Cheonnong-dong, Tongdaemun-gu
Seoul 130-743, KOREA
Email: ahn@uos.ac.kr
Younghan Kim
Soongsil University
11F Hyungnam Engineering Bldg. 317, Sangdo-Dong,
Dongjak-Gu, Seoul 156-743 Korea
E-main: yhkim@dcn.ssu.ac.kr
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Yuseon Kim
KT
17 Woomyeon-dong, Seocho-gu
Seoul 137-792, KOREA
Email: yseonkim@kt.co.kr
Sangeon Kim
KT
17 Woomyeon-dong, Seocho-gu
Seoul 137-792, KOREA
Email: sekim@kt.co.kr
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