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