Network Working Group B. Sarikaya Internet-Draft F. Xia Expires: September 11, 2008 Huawei USA March 10, 2008 Prefix Delegation Support for Mobile Networks draft-sarikaya-mext-prefix-delegation-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 September 11, 2008. Sarikaya & Xia Expires September 11, 2008 [Page 1] Internet-Draft Prefix Delegation Support March 2008 Abstract This document defines prefix delegation support for a mobile network. Mobile Router dynamically requests its Mobile Network Prefixes from its Home Agents using Binding Update. Home agents get the prefixes delegated using DHCP Prefix Delegation and reply to the Mobile Router with Binding Acknowledgement. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Nemo Prefix Delegation Using DHCP . . . . . . . . . . . . . . . 3 4. Nemo Prefix Delegation Using AAA . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 8.2. Informative references . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Intellectual Property and Copyright Statements . . . . . . . . . . 7 Sarikaya & Xia Expires September 11, 2008 [Page 2] Internet-Draft Prefix Delegation Support March 2008 1. Introduction Nemo Basic Support Protocol requires that IPv6 prefixes called Home Network Prefix(es) delegated to a Mobile Router and advertized in the Mobile Network [RFC3963]. However the protocol does not provide any means of provisioning MNPs dynamically. Prefix delegation is widely discussed in IETF 16NG, MEXT, and NETLMM Working Groups. Corresponding solutions are also introduced. NEMO deals with synchronization of Mobile Network prefixes between a Mobile Router and a Home Agent, while the method is agnostic to the way that a Home Agent gets prefixes from back end servers. [RFC3633] defines Prefix Delegation options and procedures to provide a mechanism for automated delegation of IPv6 prefixes using the Dynamic Host Configuration Protocol (DHCP). A mechanism to manage prefixes dynamically by an AAA server can also be defined. [I-D.ietf-nemo-prefix-delegation] defines prefix request option for the binding update and prefix confirm for the binding acknowledgment messages of the Nemo Basic Support Protocol. Using these messages MR can request a prefix from HA with BU and HA can give prefixes to MR with BA. However, how HA gets prefixes is not defined. 2. Terminology This document uses the terminology defined in [RFC3315], [RFC3633] and [I-D.ietf-nemo-prefix-delegation]. 3. Nemo Prefix Delegation Using DHCP We assume that the prefixes are managed by an authority that owns the Home Network and subnets it into MNPs that it assigns to the MRs. An MNP can be preassigned to the associated MR (e.g. manually or automatically with a provisioning system), or assigned dynamically by a server such as a DHCP Prefix Delegation server [I-D.ietf-nemo-prefix-delegation]. In this architecture, HA is the requesting router and the DHCP Server is the delegating router. HA needs to be collocated with a DHCP Client to solicit/request prefixes from the DHCP Server. HA is configured with the address of the delegating router which is a backend DHCP Server. The alternative architecture assigns MR to be the requesting router and requires the delegating router to be located in HA's subnet. Such an architecture is not selected in this document. Sarikaya & Xia Expires September 11, 2008 [Page 3] Internet-Draft Prefix Delegation Support March 2008 [I-D.ietf-nemo-prefix-delegation] specifies mechanism for a Mobile Router(MR) to synchronize its Mobile Network Prefixes with its Home Agents and obtain new ones dynamically. Figure 1 shows the process that a Mobile Router requests prefixes from a Home Agent. MR HA DHCP Server | | | |------->| | 1. BU with Prefix Request | |------->| 2. DHCP Solicit | |<-------| 3. DHCP Advertise | |------->| 4. DHCP Request (MNP) | |<-------| 5. DHCP Reply (MNP) |<-------| | 6. BA with Prefix Confirm Figure 1: Prefix Delegation in NEMO 1. Mobile Network Prefix request option defined in [I-D.ietf-nemo-prefix-delegation] is included in the Binding Update(BU) to indicate to the Home Agent(HA) that the MR wishes to get new prefixes assigned to it for use as Mobile Networks Prefixes. 2. DHCP Client at the HA initiates DHCP Solicit procedure to request prefixes for the MN. HA creates and transmits a Solicit message as described in sections 17.1.1, "Creation of Solicit Messages" and 17.1.2, "Transmission of Solicit Messages" of RFC 3315. HA creates an IA_PD and assigns it an IAID. HA MUST include the IA_PD option in the Solicit message. 3. The DHCP server sends an Advertise message to HA in the same way as described in section 17.2.2, "Creation and transmission of Advertise messages" of RFC 3315. 4. HA uses the same message exchanges as described in section 18, "DHCP Client-Initiated Configuration Exchange" of RFC 3315 to obtain or update prefixes from a DHCP server. HA and the DHCP server use the IA_PD Prefix option to exchange information about prefixes in much the same way as IA Address options are used for assigned addresses. 5. HA stores the prefix information it received in the Reply message. 6. Mobile Network Prefix Confirm option defined in [I-D.ietf-nemo-prefix-delegation] is included in the Binding Acknowledgement to allocate the delegated prefixes to the MR. Mobile Network Prefix Confirm option carries the prefix lifetime. Prefixes can be refreshed either by MR sending a BU or by HA sending a BA. Sarikaya & Xia Expires September 11, 2008 [Page 4] Internet-Draft Prefix Delegation Support March 2008 4. Nemo Prefix Delegation Using AAA Diameter prefix delegation application is currently to be defined. Once such an application is defined, Nemo prefix delegation using this Diameter application will be included in this section. 5. Security Considerations This document does not by itself introduce any security issues. 6. IANA Considerations None. 7. Acknowledgements 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [I-D.ietf-nemo-prefix-delegation] Kniveton, T. and P. Thubert, "Mobile Network Prefix Delegation", draft-ietf-nemo-prefix-delegation-02 (work in progress), August 2007. 8.2. Informative references [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. Sarikaya & Xia Expires September 11, 2008 [Page 5] Internet-Draft Prefix Delegation Support March 2008 Authors' Addresses Behcet Sarikaya Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 Phone: +1 972-509-5599 Email: sarikaya@ieee.org Frank Xia Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 Phone: +1 972-509-5599 Email: xiayangsong@huawei.com Sarikaya & Xia Expires September 11, 2008 [Page 6] Internet-Draft Prefix Delegation Support March 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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