As the Internet has expanded over the last several years, so have computer networks. When the first home computer was introduced in the mid-1970s, it was rare to find one computer in a household. It was also not until decades later that Internet access became a household commodity. However, as the Internet expanded and technology grew exponentially, computers and computer networks have become an integral part of our day-to-day lives. Today almost everyone you know connects to a network in one way or another via their phone, laptop, car, or any one of the million internet-capable devices. 

This book attempts to explain computer networks and security fundamentals from a practical and real-life perspective. The topics and subjects in this book are what I consider to be the essentials of networking and security based on years of industry experience. This book takes a vertical approach and focuses on the rudimentary subjects and areas that all networking practitioners and students should know to build a solid foundation. 

Good luck; I hope you are as eager and passionate to learn about the world of networking and security as I am about teaching these concepts.  

Happy Networking, 

-Al Leaston  MIS,  

Cisco Certified Academy Instructor (CCAI)