autoconf Working Group Jaehwoon Lee Internet Draft Dongguk University Expires: January 4, 2009 Sanghynn Ahn University of Seoul Younghan Kim Soongsil University Yuseon Kim Sangeon Kim KT July 5, 2008 Scope-Extended Router Advertisement for Connected MANETs draft-jaehwoon-autoconf-sera-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 January 4, 2009. Copyright Notice Copyright (C) The IETF Trust (2008). Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 1] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Abstract In the connected MANET, the MANET Border Router (MBR) is used to connect the MANET with the external network and MANET nodes are required to know the MBR address to communicate with hosts in the external network. One way of acquiring the MBR address is to use the Router Advertisement (RA) and the Router Solicitation (RS) messages. In order to allow RA/RS messages to be delivered in the multi-hop MANET, the modified RA/RS message has been defined [5]. However, this approach may incur the duplicate packet reception problem due to rebroadcasting of received RA/RS messages to its neighbors. In this draft, we define the scope-extended Router Advertisement/ Solicitation message for announcing/solicitating the MBR address in the connected MANET. In the scope-extended RA/RS message, a new message field, the sequence number field, is defined so that duplicate RA/RS messages can be detected based on the sequence number and the IP address included in the message. Table of Contents 1. Introduction..................................................3 2. Terminology...................................................3 3. Message Format................................................4 3.1 IPv4......................................................4 3.1.1 ICMP Scope-Extended Router Solicitation Message.....4 3.1.2 ICMP Scope-Extended Router Advertisement Message....5 3.2 IPv6......................................................6 3.2.1 ICMP Scope-Extended Router Solicitation Message.....6 3.2.2 ICMP Scope-Extended Router Advertisement Message....8 3.3 Source Manet Address Option...............................9 4. Security Considerations.......................................9 5. IANA Considerations...........................................10 References.......................................................10 Author's Addresses...............................................10 Intellectual Property and Copyright Statements ..................12 Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 2] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 1. Introduction The mobile ad hoc network (MANET) enables mobile nodes to communicate via multiple wireless hops without the need of any wired infrastructure[1]. In a MANET, two nodes not within their transmission range have to deliver data to each other through other intermediate nodes. For forwarding packets destined to other nodes, each node must have the routing capability, i.e., the mechanism for establishing data delivery routes between any pair of source and destination nodes, as well as acting as a source and/or a destination node(s). In addition to that, the IP address auto-configuration mechanism suitable for the MANET environment is required. The MANET can be classified into the standalone MANET and the connected MANET. For the connected MANET, the MANET Border Router (MBR) which acts as the gateway connecting the MANET with the external network has been defined. Through the MBR, MANET nodes can communicate with hosts located in the external network. Therefore, MANET nodes have to know the MBR address. One way of obtaining the MBR address is to use the Simplified Multicast Forwarding (SMF)[2]. Another method is to use the Router Advertisement (RA) and the Router Solicitation (RS) messages[3-4]. However, these RA and RS messages are delivered only upto 1 hop, so can not be used in a multi-hop wireless network such as the MANET. In order to overcome this limitation, the modified RA message has been defined for the multi-hop wireless MANET [5]. However, in this approach, the duplicate packet reception problem can occur since, if a node broadcasts a RA/RS message, it can receive the same RA/RS message which was re-broadcast by one of its neighbors. In this draft, we define the scope-extended Router Advertisement/ Solicitation message for announcing/solicitating the MBR address in the connected MANET. In the scope-extended RA/RS message, a new message field, the sequence number field, is defined so that duplicate RA/RS messages can be detected based on the sequence number and the IP address included in the message. 2. Terminology No new terminology is defined in this draft. Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 3] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 3. Message Format 3.1 IPv4 In IPv4, the scope-extended router advertisement information is included in the ICMP message [3]. 3.1.1 ICMP Scope-Extended Router Solicitation Message 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sequence Number| Cur hop limit | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Originator Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IP Fields: Source Address The IP address configured at the MANET interface of the MANET router (MR) sending this message. Destination Address 224.0.0.1 or 255.255.255.255 Time-to-Live 1 ICMP Fields: Type TBD Code 0 Sequence Number This number is increased by 1 whenever the originating MR sends a scope-extended RS message. The sequence number and the originator address (see below) are used for the message duplication check. Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 4] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Cur Hop Limit Initially set to 255. An intermediate route reduces this value by 1 before rebroadcasting it. Reserved Sent as 0; ignored on reception. Originator Address The IP address assigned to the MANET interface of the MR that originates the message. 3.1.2 ICMP Scope-Extended Router Advertisement Message 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sequence Number| Cur Hop Limit | Prefix Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBR Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IP Fields: Source Address The IP address configured at the MANET interface of the MR sending this message. If this message is sent as a reply to a scope-extended RS message, this field has the IP address configured at the MANET interface of the MBR originating this scope-extended RA message. If it is a proactively sent message, this field has the IP address configured at the MANET interface of the MR sending this message. Destination Address The IP address of the MANET interface of the MR originating the scope-extended RS message, if this scope-extended RA message is sent as a reply to the scope-extended RS message. Otherwise, set to the broadcast address. Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 5] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Time-to-Live 1 if the Destination Address is the broadcast address; at least 1, otherwise. ICMP Fields: Type TBD Code 0 Sequence Number This number is increased by 1 by the MR originating the scope-extended RS message to which this scope-extended RA is sent as a reply. The sequence number and the originator address are used for the message duplication check. Cur hop limit Initially set to 255. An intermediate route reduces this value by 1 before rebroadcasting it. If the reduced value is 0, this message is silently discarded. Prefix Length The prefix length of the IPv4 address assigned to the MANET interface of the MBR. Router Address The IP address assigned to the MANET inter- face of the MBR originating this message. 3.2 IPv6 In IPv6, the scope-extended router advertisement information is defined as a part of the neighbor discovery in [4]. 3.2.1 ICMP Scope-Extended Router Solicitation Message 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sequence Number| Cur Hop Limit | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 6] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 IP Fields: Source Address The IP address configured at the MANET interface of the MR sending this message. Destination Address The all-routers multicast address or the all-nodes multicast address. Time-to-Live 255 ICMP Fields: Type TBD Code 0 Sequence Number This number is increased by 1 whenever the originating MR sends a RS message. The sequence number and the originator address are used for the message duplication check. Cur Hop Limit Initially set to 255. An intermediate route reduces this value by 1 before rebroadcasting it. If the reduced value is 0, this message is silently discarded. Options: Source Manet address [5] The IP address assigned to the MANET interface of the MR that originates the message. Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 7] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 3.2.2 ICMP Scope-Extended Router Advertisement Message 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sequence Number| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Cur Hop Limit |M|O| Reserved | Router Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reachable Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Retrans Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- IP Fields: Source Address If this message is sent as a reply to a scope-extended RS message, this field has the IP address configured at the MANET interface of the MBR originating this message. If this messages is a proactively sent message, this field has the IP address configured at the MANET interface of the MR sending this message. Destination Address Typically the Source Address of the invoking scope-extended Router Solicitation or the all-nodes multicast address. Hop Limit 255 ICMP Fields: Type TBD Code 0 Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 8] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Sequence Number This number is increased by 1 whenever the originating MBR sends a RA message. The sequence number and the originator address are used for the message duplication check. Possible options: Prefix option This option SHOULD be included. The prefix field in this option is set to the prefix of the IPv6 address configured at the MANET interface of the MBR originating this message. 3.3. Source Manet Address Option [5] 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Manet Address ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 10 Length 3 The length of the option (including the type and length fields) in units of 8 octets. Manet Address The IPv6 address configured at the MANET interface of the original source of this message. 4. Security Consideration There is no special security considerations in this draft. Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 9] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 5. IANA Considerations This draft document defines a new type in the ICMP message. An Type value for the scope-extended Router Discovery message for MANET must be assigned by IANA. References [1] I. Chakeres, J. Macker and T. Clausen, "Mobile Ad hoc Network Architecture", draft-ietf-autoconf-manetarch-07, Work in progress, Nov. 2007. [2] J. Macker, "Simplified Multicast Forwarding for MANET", draft-ietf-manet-smf-07, Work in progress, Feb. 2008. [3] S. Deering, "ICMP Router Discovery Messages", RFC 1256, Sep. 1991. [4] T. Narten, E. Nordmark, W. Simpson and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 3861, Sep. 2007. [5] R. Wakikawa, J. Malinen, C. Perkins, A. NIlsson and A. Tuominen, Global connectivity for IPv6 Mobile Ad Hoc Networks", Work in progress, Oct. 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 Jaehwoon Lee, et al. Expires Jan. 4, 2009 [Page 10] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Younghan Kim Soongsil University 11F Hyungnam Engineering Bldg. 317, Sangdo-Dong, Dongjak-Gu, Seoul 156-743 Korea E-main: yhkim@dcn.ssu.ac.kr 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 Jan. 4, 2009 [Page 11] Internet-Draft Scope-Extended Router Advertisement July 5, 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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