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

Multiple remotes and remote-random


OpenVPN has (limited) built-in support for automatic failover and load-balancing: if the connection to one OpenVPN server cannot be established, then the next configured server is chosen. The remote-random directive can be used to load-balance many OpenVPN clients across multiple OpenVPN servers. In this recipe, we will set up two OpenVPN servers and then use the remote-random directive to have a client choose either one of the two servers.

Note that OpenVPN does not offer transparent failover, in which case the existing connections are transparently migrated to another server. Transparent failover is much harder to achieve with a VPN setup (not just OpenVPN), as the secure session keys need to be migrated from one server to the other as well. This is currently not possible with OpenVPN.

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...