CONTENTS I GETTING STARTED 1. INTRODUCTION 1.1 Why security ? 1.2 Picking a security policy 1.3 Strategies for a secure network 1.4 The enthics of computer security 1.5 WARNING 2. AN OVERVIEW OF TCP/IP 2.1 The different layers 2.2 Routers and routing protocols 2.3 The domain name system 2.4 Standard services 2.5 RPC-based protocols 2.6 File transfer protocols 2.7 The “r” …