Building Linux Virtual Private Networks
"This is the VPN book I wish I'd written. It explains enough about the protocols and issues to clarify the difficulties for the novice, and supplies page after page of clearly-commented examples -- the only way to learn how to make a VPN work! Building Linux Virtual Private Networks will be at the top of my list when people ask what they should read about this complex networking topic."

Tina Bird, Security Architect, Counterpane Internet Security, Moderator of the VPN mailing list, and VPN FAQ Maintainer.

Building Linux Virtual Private Networks offers concise, step-by-step instructions for building VPNs based on both standard protocols (IPSec, SSL, SSH, PPTP) and popular Linux VPN solutions (VTun, cIPe, tinc). Through numerous examples and proven practices, you will gain important insights into choosing a VPN solution, installing and configuring it, setting up routing, configuring firewalls, measuring performance, and much more.

An interview with the lead authors is available at New Riders: Oleg Kolesnikov Interview - Bri Hatch Interview.

The book is available in stores and online, including:
Barnes and NobleBarnes And Noble

Source Code
Sample Chapter
Suggested Reading

New Riders Publishing