Mobile IPv4 RADIUS Requirements
RFC 5030

Network Working Group                                   M. Nakhjiri, Ed.
Request for Comments: 5030                                      Motorola
Category: Informational                                     K. Chowdhury
                                                        Starent Networks
                                                                 A. Lior
                                                     Bridgewater Systems
                                                                K. Leung
                                                           Cisco Systems
                                                            October 2007

                    Mobile IPv4 RADIUS Requirements

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Abstract

   This document provides an applicability statement as well as a scope
   definition for specifying Remote Authentication Dial-In User Service
   (RADIUS) extensions to support Mobile IPv4.  The goal is to allow
   specification of RADIUS attributes to assist the Mobile IPv4
   signaling procedures.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Goals and Non-Goals . . . . . . . . . . . . . . . . . . . . . . 3
     3.1.  Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
     3.2.  Non-Goals . . . . . . . . . . . . . . . . . . . . . . . . . 4
   4.  Attributes  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 6
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 6
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 7

Nakhjiri, et al.             Informational                      [Page 1]
RFC 5030            Mobile IPv4 RADIUS Requirements         October 2007

1.  Introduction

   To kick start the Mobile IPv4 [RFC3344] processing of its packets by
   Mobile IP agents, a mobile node (MN) needs to be able to acquire a
   pair of home and care of addresses (HoA and CoA, respectively), find
   a willing agent to act as a Home Agent (HA) for the MN and perform a
   registration process with the HA.  The registration process consists
   of an exchange of a registration request and a registration reply
   message between the MN and the HA.  The specification in [RFC3344]
   allows an MN to start the registration process prior to having
   acquired its home address or the address of its HA.  Acquiring those
   parameters by the MN is typically part of a process referred to as
   bootstrapping.

   Successful processing of registration request and reply messages,
   among other things, depends on successful creation and verification
   of a number of authentication extensions developed specifically to
   protect the integrity and security of these messages and the entities
   processing them, i.e., MN, HA and some times, Foreign Agents (FAs)
   [RFC3344].  Creation as well as verification of these extensions
   requires existence of trust relationships and shared keys between MN
   and each of the mobility agents.  However, creation of these trust
   relationships, typically referred to as mobility security
   associations (MSAs), is considered outside the scope of the base
   Mobile IPv4 specification defined in [RFC3344].  Avoiding the
   scalability issues arising from creating static security associations
   between an MN and all possible mobility agents is desired.  Thus,
   establishing the associations dynamically, using the pre-existing
   relationship between the MN and the AAA server, is preferred.

   To allow for utilization of an existing AAA infrastructure in the
   bootstrapping of the Mobile IPv4 parameters and security
   relationships, the Mobile IPv4 working group has developed Mobile
   IPv4 extensions to allow the MN to authenticate to the home AAA
   server [RFC4721].  The extensions also allow the MN to request
   assistance from the AAA server in creation of mobility security
   associations [RFC3957] with the mobility agents, using the pre-
   established trust relationship between the MN and its home AAA
   server.

   While Mobile IPv4 extensions are necessary for implementing a
   utilization of the AAA infrastructure for Mobile IPv4 purposes, they
   are not sufficient.  The interaction between the MN and the mobility
   agents (HA and FA) is based on Mobile IP signaling.  However, the