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 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. 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. This Internet-Draft will expire on August 17, 2009. Copyright Notice Copyright (c) 2009 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 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Jaehwoon Lee, et al. Expires August 17, 2009 [Page 1] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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 Jaehwoon Lee, et al. Expires August 17, 2009 [Page 2] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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 Jaehwoon Lee, et al. Expires August 17, 2009 [Page 3] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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) | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+ Jaehwoon Lee, et al. Expires August 17, 2009 [Page 4] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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 Jaehwoon Lee, et al. Expires August 17, 2009 [Page 5] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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. Jaehwoon Lee, et al. Expires August 17, 2009 [Page 6] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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 Jaehwoon Lee, et al. Expires August 17, 2009 [Page 7] Internet-Draft DHCP options for MANET prefix Febraury 18, 2009 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 Jaehwoon Lee, et al. Expires August 17, 2009 [Page 8]