Network Working Group G. Tsirtsis Internet-Draft V. Park Intended status: Standards Track V. Narayanan Expires:
September 20, 2007May 9, 2008 Qualcomm K. Leung Cisco March 19,November 6, 2007 Dynamic Prefix Allocation for NEMOv4 draft-ietf-mip4-nemov4-dynamic-00.txtdraft-ietf-mip4-nemov4-dynamic-01.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 September 20, 2007.May 9, 2008. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract The base NEMOv4 specification defines extensions to Mobile IPv4 for mobile networks. This specification defines a dynamic prefix allocation mechanism. Table of Contents 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Dynamic Mobile Prefix allocation . . . . . . . . . . . . . . . 5 3.1. Mobile Client Considerations . . . . . . . . . . . . . . . 5 3.2. Home Agent Considerations . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. Normative References . . . . . . . . . . . . . . . . . . . . . 89 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 910 Intellectual Property and Copyright Statements . . . . . . . . . . 1011 1. Requirements notation 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 [RFC2119]. 2. Introduction The base NEMOv4 specification [NEMOv4][I-D.ietf-mip4-nemo-v4-base] defines extensions to Mobile IPv4 [RFC3344] for mobile networks. This specification adds support for dynamic allocation of mobile prefixes by the home agent. 3. Dynamic Mobile Prefix allocation The following extension is defined according to this specification. 3.1. Mobile Client Considerations [NEMOv4][I-D.ietf-mip4-nemo-v4-base] defines that the prefix field of the mobile network request extension can not be set to zero. According to this specification, however, a mobile client MAY include one or more mobile network request extensions with the prefix field set to zero. Such mobile network request extensions indicate that the mobile client requests mobile network prefix(es) to be assigned to it by the home agent. In this case, the mobile client MAY set the prefix length field of such extensions to zero or to a length of its choice as a hint to the home agent. According to this specification, mobile network request extensions with the prefix field set to zero MAY be included in a registration request message either during initial registration or during a subsequent registration. When a mobile client receives a registration reply it MUST process it as defined in MIPv4 [RFC3344] and [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. If one or more network acknowledgement extension are included with the Code field set to "Success" the mobile client SHOULD treat the prefixes in the corresponding prefix fields as allocated prefixes and create the appropriate bindings as defined in [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. If in response to a registration request with a mobile network request extension with the prefix field set to zero, a mobile client receives a registration reply with a Code field set to 70 "poorly formed request", it may use it as a hint that the home agent does not support dynamic prefix allocation. [Ed. Note: alternatively [NEMOv4][I-D.ietf-mip4-nemo-v4-base] should define an appropriate Code in the Mobile Network Acknowledgment extension e.g., "Bad Prefix" 3.2. Home Agent Considerations A home agent receiving a mobile network request extension with the prefix field set to zero MAY return a mobile network acknowledgement extension [NEMOv4][I-D.ietf-mip4-nemo-v4-base] with the prefix field set to the prefix allocated to the mobile client. The length of that prefix is at the discretion of the home agent. The home agent MAY take into account the prefix length hint if one is included in the mobile network request extension. Once the home agent allocates a prefix it MUST maintain the prefix registration table as defined in [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. Alternatively the home agent MAY return a mobile network acknowledgement extension with the Code field set to one of the negative codes defined in [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. Dynamic mobile prefix allocation as defined in this specification MAY be combined with dynamic home address allocation as defined in MIPv4 [RFC3344]. In other words the home address field of the registration request message MAY be set to zero while the message also includes one or more mobile network request extensions with the prefix field also set to zero. Once the home agent allocates a prefix it MUST maintain the prefix registration table as defined in [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. For dynamic prefix allocation the mobile client's home address MAY be used to identify the client if it is not set to zero. If the home Otherwise, as defined in MIPv4 [RFC3344] and NAI [RFC2794], the NAI [RFC2794] extension needs to be included in the registration request, in which case the same extension SHOULD be used to identify the mobile client for prefix allocation purposes. 4. Security Considerations This specification operates in the security constraints and requirements of MIPv4 [RFC3344], NAI [RFC2794] and [NEMOv4].[I-D.ietf-mip4-nemo-v4-base]. Home agent implementations SHOULD take steps to prevent address exhaustion attacks. One way to limit the effectiveness of such an attack is to limit the number and size of prefixes any one mobile router can be allocated. 5. IANA Considerations This document has no actions for IANA 6. Normative References [I-D.ietf-mip4-nemo-v4-base] Leung, K., "IPv4 NetworkDommety, G., Narayanan, V., and A. Petrescu, "Network Mobility (NEMO) Protocol", draft-ietf-mip4-nemo-v4-base-00Extensions for Mobile IPv4", draft-ietf-mip4-nemo-v4-base-06 (work in progress), MarchOctober 2007. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2794] Calhoun, P. and C. Perkins, "Mobile IP Network Access Identifier Extension for IPv4", RFC 2794, March 2000. [RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, August 2002. Authors' Addresses George Tsirtsis Qualcomm Phone: +908-443-8174 Email: firstname.lastname@example.org Vincent Park Qualcomm Phone: +908-947-7084 Email: email@example.com Vidya Narayana Qualcomm Phone: +858-845-2483 Email: firstname.lastname@example.org Kent Leung Cisco Phone: +408-526-5030 Email: email@example.com Full Copyright Statement Copyright (C) The IETF Trust (2007). 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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