Book Image

OpenVPN Cookbook - Second Edition

By : Jan Just Keijser
Book Image

OpenVPN Cookbook - Second Edition

By: Jan Just Keijser

Overview of this book

OpenVPN provides an extensible VPN framework that has been designed to ease site-specific customization, such as providing the capability to distribute a customized installation package to clients, and supporting alternative authentication methods via OpenVPN’s plugin module interface. This book provides you with many different recipes to help you set up, monitor, and troubleshoot an OpenVPN network. You will learn to configure a scalable, load-balanced VPN server farm that can handle thousands of dynamic connections from incoming VPN clients. You will also get to grips with the encryption, authentication, security, extensibility, and certifications features of OpenSSL. You will also get an understanding of IPv6 support and will get a demonstration of how to establish a connection via IPv64. This book will explore all the advanced features of OpenVPN and even some undocumented options, covering all the common network setups such as point-to-point networks and multi-client TUN-style and TAP-style networks. Finally, you will learn to manage, secure, and troubleshoot your virtual private networks using OpenVPN 2.4.
Table of Contents (17 chapters)
OpenVPN Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Linux - using pull-resolv-conf


One of the most common pitfalls when setting up a VPN connection on Linux is when the OpenVPN server pushes out new DNS settings. In the previous recipe, we saw that the NetworkManager-openvpn plugin also updated the system configuration file that contained the DNS setting, /etc/resolv.conf. If the command line is used, this is not done automatically. By default, OpenVPN comes with two scripts to add and remove DNS servers from the /etc/resolv.conf file. This recipe will show how to use these scripts.

Getting ready

We will use the following network layout:

Set up the client and server certificates using the first recipe from Chapter 2Client-server IP-only Networks. For this recipe, the server computer was running CentOS 6 Linux and OpenVPN 2.3.11. The client was running Fedora 22 Linux and OpenVPN 2.3.11. Keep the basic-udp-server.conf configuration file from the Server-side routing recipe from Chapter 2Client-server IP-only Networks, as well as the  basic...