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

Chapter 5. Advanced Deployment Scenarios in tun Mode

The basic configuration of a VPN is relatively simple but integrating that VPN with the rest of the network is a much more difficult task. In this chapter, we will explore some advanced deployment scenarios for OpenVPN, which goes beyond the basic installation and configuration of a VPN. Some of these scenarios are based on actual questions from users on the OpenVPN mailing lists, forum, and IRC channel. We will cover the following topics:

  • Enabling (Windows) file sharing over the VPN

  • Integration with backend authentication mechanisms such as PAM and LDAP

  • Filtering VPN traffic (firewall)

  • Policy-based routing for enhanced security

  • Dealing with public versus private network adapters in Windows 7

  • Using OpenVPN with HTTP or SOCKS proxies

The examples presented throughout this chapter rely on the examples from the previous chapter, Chapter 4, Client/Server Mode with tun Devices. Most notably, the Basic production-level configuration files and Adding...