Book Image

Troubleshooting OpenVPN

By : Eric F Crist
Book Image

Troubleshooting OpenVPN

By: Eric F Crist

Overview of this book

OpenVPN, the most widely used open source VPN package, allows you to create a secure network across systems, keeping your private data secure. Connectivity and other issues are a pain to deal with, especially if they are impacting your business. This book will help you resolve the issues faced by OpenVPN users and teach the techniques on how to troubleshoot it like a true expert. This book is a one stop solution for troubleshooting any issue related to OpenVPN. We will start by introducing you to troubleshooting techniques such as Packet Sniffing, Log Parsing, and OpenSSL. You will see how to overcome operating system specific errors. Later on, you will get to know about network and routing errors by exploring the concepts of IPv4 and IPv6 networking issues. You will discover how to overcome these issues to improve the performance of your OpenVPN deployment. By the end of the book, you will know the best practices, tips, and tricks to ensure the smooth running of your OpenVPN.
Table of Contents (16 chapters)

Connectivity


The first step in connecting to a remote VPN server is actually having the ability to connect outbound from the current network, whether that is from home, a coffee shop, a corporate network, or via your favorite mobile hotspot. If the outbound connection is blocked, none of the other configurations will matter.

Inbound connection--server

On the server side, connectivity can prove a bit more difficult. The OpenVPN server needs to either reside directly on the public network, or port-forwarding rules need to be applied to deliver the traffic to the correct system. All servers used across the general Internet will require some form of routable or public IP address.

I will cover both a simple public address case in addition to the slightly more complicated port-redirection case. It is good to keep in mind that many corporate networks will seldom place the VPN server directly on the public Internet. Instead, they will usually use multiple layers of firewalls, intrusion detection system...