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

Optimizing performance using ping


In this recipe, we will use the low-level ping command to determine the optimal Maximum Transfer Unit (MTU) size for our OpenVPN setup. Finding the right MTU size can have a tremendous impact on performance, especially, when using satellite links, or even some cable/ADSL providers. Especially, broadband connections using the PPPoE (PPP over Ethernet) protocol often have a non-standard MTU size. In a regular LAN setup, it is hardly ever required to optimize the MTU size, as OpenVPN's' default settings are close to optimal.

Getting ready

Make sure the client and the server computers are connected over a network. For this recipe, the server computer was running CentOS 6 Linux. The client was running Fedora 22 Linux, but instructions for a Windows client are given as well.

How to do it...

  1. We first verify that we can reach the server from the client:

    [client]$ ping -c 2 <openvpn-server-ip>
    

    This will send two ICMP ping packets to the server and two replies should...