This book is a comprehensive guide to using OpenVPN for building both secure VPNs. The book is written in a very friendly style that makes this complex topic easy and a joy to read. It first covers basic VPN concepts, then moves to introduce basic OpenVPN configurations, before covering advanced uses of OpenVPN. This book is for both experienced and new OpenVPN users. Network administrators and any one who is interested in building secure VPNs using OpenVPN. It presumes basic knowledge of Linux, but no knowledge of VPNs is required. All basic VPN and relevant security concepts are covered.
I first read through the book's table of contents and was pleasantly surprised that they supported Linux, however after the "Installing OpenVPN" part of the book, you see a very obvious turn towards Windows administration.
The first practical chapter where you have to create your first OpenVPN tunnel has no Linux equivalent. You start your journey with a rabbit hole.
If you're using Linux, it's just not possible to follow everything through. You're basically left on your own to figure stuff out.
The fact that Openvpn: Bulding and Integrating VPNetworks is also written with tools from 10 years ago, certainly doesn't help.
My summary: If you're using Windows, you may get something useful. For me the book didn't bring anything new regarding OpenVPN knowledge and also had 0 practical examples.