MEXT Working Group Hong-Ke Zhang Internet Draft Zhi-Wei Yan Expires: March 2009 Si-Dong Zhang Hua-Chun Zhou Jian-Feng Guan Beijing Jiaotong University September 30, 2008 Router Advertisement Extension to Recognize Access Location for Mobile Router draft-zhang-mext-ramr-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 March 30,2009. Abstract The Router Advertisement message in IPv6 Neighbor Discovery Protocol [2] contains an 8-bit field reserved for single-bit flags. Several protocols have reserved flags in this field and others are preparing to reserve a sufficient number of flags to exhaust the field. This document defines a flag to the Router Advertisement message that extends the available number of flag bits available. The extended flag defined in this document is mainly used by Mobile Router to identify its location. Zhang et al. Expires March 30, 2009 [Page 1] Internet-Draft RA extension for MR September 2008 Conventions used in this document 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 [1]. Table of Contents 1. Introduction...................................................2 2. Extended RA....................................................2 3. Security Considerations........................................5 4. References.....................................................5 Author's Addresses................................................5 Intellectual Property Statement...................................5 Full Copyright Statement..........................................6 Acknowledgment....................................................6 1. Introduction The Router Advertisement message in IPv6 Neighbor Discovery Protocol [2] contains an 8-bit field reserved for single-bit flags. Several protocols have reserved flags in this field and others are preparing to reserve a sufficient number of flags to exhaust this field. The RA may be sent by Access Router including the Mobile Router (MR) in mobile network. When several MR are connected in a nested manner, they do not know the nested situation according to the basic NEMO protocol. So it is not convenient to do some special configuration and optimization, such as route optimization. Routers send out Router Advertisement message periodically, or in response to a Router Solicitation. This document defines a flag for the Router Advertisement message. The extended format of RA is illustrated in figure 1. 2. Extended RA This document defines a flag for the Router Advertisement message. The extended format of RA is illustrated in figure 1. Zhang et al. Expires March 30,2009 [Page 2] Internet-Draft RA extension for MR September 2008 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Cur Hop Limit |M|O|R| Reserved | Router Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reachable Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Retrans Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- Figure 1: Extended RA Type 134 Code 0 Checksum The ICMP checksum. See [ICMPv6]. Cur Hop Limit 8-bit unsigned integer. The default value that should be placed in the Hop Count field of the IP header for outgoing IP packets. A value of zero means unspecified (by this router). Zhang et al. Expires March 30,2009 [Page 3] Internet-Draft RA extension for MR September 2008 M 1-bit "Managed address configuration" flag. When set, hosts use the administered (stateful) protocol for address autoconfiguration in addition to any addresses autoconfigured using stateless address autoconfiguration. The use of this flag is described in [ADDRCONF]. O 1-bit "Other stateful configuration" flag. When set, hosts use the administered (stateful) protocol for autoconfiguration of other (non- address) information. The use of this flag is described in [ADDRCONF]. R 1-bit "Mobile Router Discovery" flag. This flag is only used by the mobile router. When the mobile router receives a RA message containing this flag, it will recognize that this message is sent out by a mobile router and it they connect in a nested manner, then the flag in its RA message should be set to 1. Otherwise, when the mobile router receives a RA message without this flag, it will recognize it connects to a common access router, and then the flag in its RA message should be set to 0. So, the mobile router with this flag set to 0 is the root mobile router, while the mobile router with this flag set to 1 is the nested mobile router. Reserved A 5-bit unused field. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. Router Lifetime 16-bit unsigned integer. The lifetime associated with the default router in units of seconds. The maximum value corresponds to 18.2 hours. A Lifetime of 0 indicates that the router is not a default router and SHOULD NOT appear on the default router list. Reachable Time 32-bit unsigned integer. The time, in milliseconds, that a node assumes a neighbor is reachable after having received a reachability confirmation. A value of zero means unspecified (by this router). Retrans Timer Zhang et al. Expires March 30,2009 [Page 4] Internet-Draft RA extension for MR September 2008 32-bit unsigned integer. The time, in milliseconds, between retransmitted Neighbor Solicitation messages. A value of zero means unspecified (by this router). 3. Security Considerations When a malicious MR broadcast RA with the false flag, hierarchy of nested mobile network can be confused. 4. References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery for IP Version 6 (IPv6)", RFC 2461, December 1998. Author's Addresses Hong-Ke Zhang, Zhi-Wei Yan, Hua-Chun Zhou, Si-Dong Zhang, Jian-Feng Guan NGI Research Center Beijing Jiaotong University of China Phone: +861051685677 Email:hkzhang@bjtu.edu.cn 06120232@bjtu.edu.cn hchzhou@bjtu.edu.cn sdzhang@center.njtu.edu.cn guanjian8632@163.com Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of Zhang et al. Expires March 30,2009 [Page 5] Internet-Draft RA extension for MR September 2008 such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. 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. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Zhang et al. Expires March 30,2009 [Page 6]