Building Linux Virtual Private Networks
We strived to make sure that everything you need to establish a VPN using Linux was contained in Building Linux Virtual Private Networks. However these are some other books we'd suggest if you are looking for additional information to help with Linux and security related issues.

Hacking Linux Exposed, Second Edition
by Bri Hatch, James Lee
Paperback - 700 Pages (December 2002)
Osborne/McGraw-Hill; ISBN: 0072225645

Your VPN is only as secure as your Linux machines. Hacking Linux Exposed, Second Edition (by one of the Building Linux Virtual Private Networks authors) shows you everything you need to keep your machine safe from intruders.

Amazon Barnes and Noble Booksamillion 

Linux Firewalls Second Edition
by Robert L. Ziegler
Textbook Binding - 592 pages, 2nd edition (October, 2001)
New Riders Publishing; ISBN: 0735710996

Step-by-step descriptions of how to configure Linux firewalls, both ipchains and iptables. This book will help you limit the access of your VPN users if you want additional security. It doesn't specifically cover VPN and firewall issues, but we cover those in Building Linux Virtual Private Networks already.

Amazon Barnes and Noble Booksamillion 

Applied Cryptography: Protocols, Algorithms, and Source Code in C, 2nd Edition.
by Bruce Schneier
Paperback - 784 pages 2 edition (October, 1995)
John Wiley & Sons; ISBN: 0471117099

The authoritative cryptography reference. A good introduction and reference for the curious and the programmers alike. Can help you understand the crypto protocols we discuss for our VPNs

Amazon Barnes and Noble Booksamillion 

TCP/IP Illustrated, Volume 1 : The Protocols
by W. Richard Stevens
Hardcover - 576 pages Vol 001 (January, 1994)
Addison-Wesley; ISBN: 0201633469

If you want to understand the IP networking suite, the W. Richard Stevens books are the authority.

Amazon Barnes and Noble Booksamillion 

TCP/IP Illustrated, Volume 2 : The Implementation
by Gary R. Wright, W. Richard Stevens
Hardcover Vol 002 (January, 1995)
Addison-Wesley; ISBN: 020163354X

Volume 2 covers networking source code in more detail.

Amazon Barnes and Noble Booksamillion 

Network Intrusion Detection, 2nd edition
by Stephen Northcutt, Donald McLachlan, Judy Novak
Paperback - 450 pages 2nd edition (September, 2000)
New Riders Publishing; ISBN: 0735710082

Analysis of real-life intrusions via network dumps and detection tools

Amazon Barnes and Noble Booksamillion 

SSH, the Secure Shell : The Definitive Guide
by Daniel J. Barrett, Richard Silverman
Paperback - 558 pages (February, 2001)
O'Reilly & Associates; ISBN: 0596000111

You're going to want to administer your VPN machines, and SSH is the only way to go.

Amazon Barnes and Noble Booksamillion 

Learning the vi Editor (6th Edition)
by Linda Lamb, Arnold Robbins
Paperback - 327 pages 6 edition (November, 1998)
O'Reilly & Associates; ISBN: 1565924266

Every VPN administrator is going to need to edit configuration files once in a while. Best to learn how to use a real editor.

Amazon Barnes and Noble Booksamillion 

Source Code
Sample Chapter
Suggested Reading

New Riders Publishing