Firewalls

Contents

Foreword xvii

Introduction xix

Acknowledgments xxix

Section I—Overview of Firewall Technology 1

1 Firewalls: What Are They? 3

1.1 Chapter objectives 3

1.2 Firewall defined 7

1.3 Why firewalls? 8

1.3.1 The need for firewalls 9

1.4 Benefits of firewalls 12

1.4.1 Protection from vulnerable services 13

1.4.2 Controlled access to site systems 13

1.4.3 Concentrated security 14

1.5 Enhanced privacy 15

1.5.1 Logging and statistics on network use and misuse 15

1.5.2 Policy enforcement 15

1.6 Limitations of firewalls 16

1.6.1 What about viruses? 18

1.7 Summary 19

1.8 References 21

2 Type of Firewall Security Policy 23

2.1 Chapter objectives 23

2.2 Firewall protection ...