Motivation for the Book

In my work designing, implementing, and troubleshooting VPNs, I noticed a lack of a single source that not only described the commands and techniques to troubleshoot VPNs, but also included the detailed protocol information necessary to correctly interpret troubleshooting command output. This book will provide you with that single source, and it will (hopefully) save you a lot of time and stress when troubleshooting your VPNs.