Book Image

Mastering OpenVPN

By : Jan Just Keijser, Eric F Crist
Book Image

Mastering OpenVPN

By: Jan Just Keijser, Eric F Crist

Overview of this book

Security on the internet is increasingly vital to both businesses and individuals. Encrypting network traffic using Virtual Private Networks is one method to enhance security. The internet, corporate, and “free internet” networks grow more hostile every day. OpenVPN, the most widely used open source VPN package, allows you to create a secure network across these systems, keeping your private data secure. The main advantage of using OpenVPN is its portability, which allows it to be embedded into several systems. This book is an advanced guide that will help you build secure Virtual Private Networks using OpenVPN. You will begin your journey with an exploration of OpenVPN, while discussing its modes of operation, its clients, its secret keys, and their format types. You will explore PKI: its setting up and working, PAM authentication, and MTU troubleshooting. Next, client-server mode is discussed, the most commonly used deployment model, and you will learn about the two modes of operation using "tun" and "tap" devices. The book then progresses to more advanced concepts, such as deployment scenarios in tun devices which will include integration with back-end authentication, and securing your OpenVPN server using iptables, scripting, plugins, and using OpenVPN on mobile devices and networks. Finally, you will discover the strengths and weaknesses of the current OpenVPN implementation, understand the future directions of OpenVPN, and delve into the troubleshooting techniques for OpenVPN. By the end of the book, you will be able to build secure private networks across the internet and hostile networks with confidence.
Table of Contents (17 chapters)
Mastering OpenVPN
About the Authors
About the Reviewers


After spending years in the OpenVPN IRC channel and on the OpenVPN support forum, there are some recurring difficulties among the server administration user base: basic networking and routing, X.509 certificate management, and user or client authentication. Having now read this book, you should have a solid grasp of these concepts and understand the underlying mechanisms. The differences between the tun and tap virtual network adapters have been discussed as well.

OpenVPN is a very active open source project and is ever evolving. The techniques and examples within Mastering OpenVPN will likely not go stale in the near future. Inefficiencies within the code are anticipated, however, so we strongly recommend that you read the manual (man page) available at

Like most open source projects, OpenVPN needs more help—more volunteers to help moderate the forum and help on IRC, and additional developers to help increase the...