RFC 2401 (rfc2401) - Page 1 of 66


Security Architecture for the Internet Protocol



Alternative Format: Original Text Document



Network Working Group                                            S. Kent
Request for Comments: 2401                                      BBN Corp
Obsoletes: 1825                                              R. Atkinson
Category: Standards Track                                  @Home Network
                                                           November 1998


            Security Architecture for the Internet Protocol

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Table of Contents

1. Introduction........................................................3
  1.1 Summary of Contents of Document..................................3
  1.2 Audience.........................................................3
  1.3 Related Documents................................................4
2. Design Objectives...................................................4
  2.1 Goals/Objectives/Requirements/Problem Description................4
  2.2 Caveats and Assumptions..........................................5
3. System Overview.....................................................5
  3.1 What IPsec Does..................................................6
  3.2 How IPsec Works..................................................6
  3.3 Where IPsec May Be Implemented...................................7
4. Security Associations...............................................8
  4.1 Definition and Scope.............................................8
  4.2 Security Association Functionality..............................10
  4.3 Combining Security Associations.................................11
  4.4 Security Association Databases..................................13
     4.4.1 The Security Policy Database (SPD).........................14
     4.4.2 Selectors..................................................17
     4.4.3 Security Association Database (SAD)........................21
  4.5 Basic Combinations of Security Associations.....................24
  4.6 SA and Key Management...........................................26
     4.6.1 Manual Techniques..........................................27
     4.6.2 Automated SA and Key Management............................27
     4.6.3 Locating a Security Gateway................................28
  4.7 Security Associations and Multicast.............................29



Kent & Atkinson             Standards Track