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


In this chapter, you learned some basic techniques for troubleshooting and tuning OpenVPN. You also got an insight into reading the client and server log files. You learned how to detect and fix some of the most often-made mistakes. Most questions on the OpenVPN e-mail list are about routing issues, therefore we discussed detecting and fixing routing problems. Finally, there is a large difference between a working setup and a well-working setup, so we looked at examples on how to detect and address performance issues.

Of course, OpenVPN is not perfect, and therefore your non-working setup could also be caused by a bug in OpenVPN itself. There are several channels for reporting bugs, including an e-mail list (), an IRC channel (#openvpn on IRC), and a forum website ( You can also report feature requests or wish lists to these channels, some of which might make it into a future version of OpenVPN.