Virtual Private Networks, Second Edition | O REILLY . J iTn i . it I .illi jfi ijil-. f mv Tttnitr. .i n hirt riict t lu J twif Ih-H ulc Nell Virtual I Private Networks Virtual Private Networks Second Edition Charlie Scott Paul Wolfe Mike Erwin Publisher O Reilly Second Edition January 1999 ISBN 1-56592-529-7 225 pages This book explains how to build a Virtual Private Network VPN a collection of technologies that creates secure collections or tunnels over regular Internet lines. It discusses costs configuration and how to install and use technologies that are available for Windows NT and UNIX such as PPTP and L2TP Altavista Tunnel Cisco PIX and the secure shell SSH . New features in the second edition include SSH and an expanded description of the IPSec standard. Table of Contents Preface . 1 Audience. 1 Contents of This Book. 1 Conventions Used in This Book. 3 Comments and Questions. 4 Updates. 4 Acknowledgments. 4 1. Why Build a Virtual Private Network . 6 What Does a VPN Do . 6 Security Risks of the Internet. 8 How VPNs Solve Internet Security Issues. 9 VPN Solutions. 12 A Note on IP Address and Domain Name Conventions Used in This Book. 13 2. Basic VPN Technologies. 14 Firewall Deployment. 14 Encryption and Authentication. 24 VPN Protocols. 32 Methodologies for Compromising VPNs. 36 Patents and Legal Ramifications. 40 3. Wide Area Remote Access and the VPN. 42 General WAN RAS and VPN Concepts. 42 VPN Versus WAN. 44 VPN Versus RAS. 50 4. Implementing Layer 2 Connections. 57 Differences Between PPTP L2F and L2TP. 57 How PPTP Works. 58 Features of PPTP. 67 5. Configuring and Testing Layer 2 Connections. 69 Installing and Configuring PPTP on a Windows NT RAS Server. 69 Configuring PPTP for Dial-up Networking on a Windows NT Client. 76 Configuring PPTP for Dial-up Networking on a Windows 95 or 98 Client. 77 Enabling PPTP on Remote Access Switches. 80 Making the Calls. 83 Troubleshooting Problems. 84 Using PPTP with .
