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

How to optimize performance by using ping and iperf

Getting maximum performance out of an OpenVPN setup can be difficult to achieve. On a clean Ethernet network, the default settings of OpenVPN are fairly good. However, some tuning is required on gigabit-speed networks.

When an ADSL or cable-modem connection is used, performance is also usually pretty good. However, under certain circumstances, the performance of our OpenVPN tunnel can fall way behind the performance of the normal network. These circumstances are almost always ISP-dependent, but nevertheless, it is worthwhile exploring how to increase performance.

The key to optimizing performance is to have good tools for measuring performance in the first place. Two basic, yet invaluable, tools for measuring network performance are ping and iperf. The iperf tool is readily available on Linux, FreeBSD, and Mac OS. There are ports available for Windows and even Android.

Using ping

Using ping, we can determine the optimal MTU size for our network...