"This book is a definitive guide on modern IPsec VPN theory and practice.This book goes over the theory and also the practical applications on IKEv2. It is extremely thorough, but at over 650 pages, you could quickly ascertain that it is comprehensive. It covers IPv4 and IPv6 and mixed-mode examples...Great coverage of FlexVPN. If you currently use DMVPN or GetVPN today, you might want to also consider FlexVPN for your next deployment as it has many benefits. Numerous great CLI examples and many good diagrams to illustrate the concepts.
If you think you already know IPsec and IKE negotiations, you will be surprised to learn many new concepts by reading this book...Many times I wish I had a book like this to help distill many complex IETF RFCs into “plain English” and provide practical and actionable security best practices."
—Scott Hogg, Reviewer Program