INTERNET DRAFT Pat R. Calhoun Category: Standards Track Charles E. Perkins Title: draft-ietf-mobileip-home-addr-alloc-00.txt Sun Laboratories, Inc. Date: November 1998 Mobile IP Dynamic Home Address Allocation Extensions Status of this Memo This document is a submission by the Mobile IP Working Group of the Internet Engineering Task Force (IETF). Comments should be submitted to the mobile-ip@smallworks.com mailing list. Distribution of this memo is unlimited. This document is an Internet-Draft. 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.'' To view the entire list of current Internet-Drafts, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). Abstract RFC2002 defines a method for a Mobile Node to be assigned a Home Agent dynamically through the use of a limited broadcast message. However, most corporate networks do not allow such packets to traverse through their firewall, which renders this feature difficult to use. This draft introduces new entity named the Home Domain Allocation Agency (HDAA) that can dynamically assign a Home Address to the Mobile Node. This draft also proposes a method for the HDAA to assign a dynamic Home Agent to the Mobile Node. Table of Contents 1.0 Introduction 2.0 Mobile IP Registration Extensions 2.1 Mobile-Node-NAI Extension 3.0 Security Analysis 4.0 References 5.0 Acknowledgements 6.0 Chairs' Addresses 7.0 Author's Address 1.0 Introduction RFC2002 defines a method for a Mobile Node to be assigned a Home Agent dynamically through the use of a limited broadcast message. However, most corporate networks do not allow such packets to traverse their firewall. The use of the limited broadcast ensured that the Home Agent assigned to the Mobile Node resided on a specific subnet, therefore it was not necessary to assign a dynamic IP Address to the Mobile Node. This draft introduces the Mobile-Node-NAI extension to the Registration Request message from a Mobile Node. A message that includes the Network Access identifier (NAI) [4] MAY have the Home Address field in the Registration Request set to zero (0) to request that one be assigned. The message MAY also have the Home Agent field set to either zero (0) or -1 to request that one be dynamically assigned. The Home Agent field set to 0.0.0.0 indicates that the Mobile Node wishes to have a Home Agent assigned either within the foreign or the home domain. A Home Agent field set to 255.255.255.255 indicates that the Mobile Node wishes to have a Home Agent assigned only within its home domain. Upon receipt of this message, the Foreign Agent must forward the request to the HDAA, which is able to assign the Home Address. The domain portion of the NAI is used to identify the Mobile Node's Home Domain, and thus to identify where the Registration Request should be forwarded. The DIAMETER Mobile IP extension [6] defines a method of resolving the Home Address allocator, but this document will refer to a generic method for full generality. In the following figure, we introduce the Home Domain Allocation Agency (HDAA), which assigns a Home Address, and possibly a Home Agent, within the Home Domain. The HDAA does not perform any processing on the Registration Request, but simply forwards the request along with the newly allocated IP address to a Home Agent within the network that is able to handle the request. +------+ | | +---+ HA-1 | +------+ +------+ +------+ | | | | | | | | | | +------+ | MN |-------| FA |-------| HDAA +---+ ... | | | | | | | +------+ +------+ +------+ +------+ | | | +---+ HA-n | | | +------+ Upon receipt of the Registration Request, the Foreign Agent extracts the Mobile Node's NAI and finds the domain name associated with it. The Foreign Agentor its proxy, then finds the HDAA that handles requests for the Mobile Node's domain. The selection of HDAAis outside of the scope of this specification, but is typically set up by service agreements between the foreign and the home domain. The Registration Reply from the Home Agent MUST include the Mobile- Node-NAI for identification at the Foreign Agent. The reply would also include any assigned Home Agent or Home Address. 2.0 Mobile IP Registration Extensions This section will define new Mobile IP Registration Extensions that must be used in order to use the functionality described in this document. 2.1 Mobile-Node-NAI Extension The Mobile-Node-NAI Extension contains the user or host name following the format defined in [4]. This extension is used to identify a user or host's and can be used to find a Home Agent within the requestor's home network. Since the foreign agent may not be able to use the Home Address in the reply to identify the Mobile Node, it MAY use the NAI in this extension instead. 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 | MN-NAI.. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TDB Length Must be at least 3 Mobile-Node-NAI Contains the username or host name in the format defined in [4]. 3.0 Security Considerations This document assumes that the Mobile IP messages are authenticated using a method defined by the Mobile IP protocol. This proposal does require that the Mobile Node's NAI be sent in the clear over the network and may be a security issue. 4.0 References [1] P. Calhoun, G. Montenegro, C. Perkins, "Tunnel Establishment Protocol", draft-ietf-mobileip-calhoun-tep-01.txt, Work in Progress, March 1998. [2] C. Perkins, Editor. IP Mobility Support. RFC 2002, October 1996. [3] P. R. Calhoun, A. Rubens, "DIAMETER Base Protocol", draft-calhoun-diameter-07.txt, Work in Progress, November 1998. [4] B. Aboba. "The Network Access Identifier." Internet-Draft, Work in Progress, August 1997. [5] P. Calhoun, G. Zorn, P. Pan, "DIAMETER Framework", draft-calhoun-diameter-framework-01.txt, Work in Progress, August 1998. [6] P. Calhoun, C. Perkins, "DIAMETER Mobile IP Extension", draft-calhoun-diameter-mobileip-01.txt, Work in Progress, November 1998. 5.0 Acknowledgements The author would like to thanks Gabriel Montenegro and Vipul Gupta for their useful discussions. 6.0 Chairs' Addresses The working group can be contacted via the current chairs: Jim Solomon RedBack Networks 1389 Moffett Park Drive Sunnyvale, CA 94089-1134 USA Phone: +1 408 548-3583 Fax: +1 408 548-3599 E-mail: solomon@rback.com Erik Nordmark Sun Microsystems, Inc. 901 San Antonio Road Mailstop UMPK17-202 Mountain View, California 94303 Phone: +1 650 786-5166 Fax: +1 650 786-5896 E-Mail: erik.nordmark@eng.sun.com 7.0 Author's Address Questions about this memo can be directed to: Pat R. Calhoun Technology Development Sun Microsystems, Inc. 15 Network Circle Menlo Park, California, 94025 USA Phone: 1-650-786-7733 Fax: 1-650-786-6445 E-mail: pat.calhoun@eng.sun.com Charles E. Perkins Technology Development Sun Microsystems, Inc. 15 Network Circle Menlo Park, California, 94025 USA Phone: 1-650-786-6464 Fax: 1-650-786-6445 E-mail: charles.perkins@eng.sun.com