TODD LAMMLE, Cisco certified in almost every category, is the authority on Cisco networking and certification. His three decades of real-world experience is prevalent in his writing. He is an experienced networking engineer with very practical experience working on the largest bounded and unbounded networks in the world at such companies as Xerox, Hughes Aircraft, Texaco, AAA, Cisco, and Toshiba, among many others. Todd has published over 60 books, including the very popular and bestselling CCNA Cisco Certified Network Associate Study Guide and Cisco Firepower NGIPS. Todd runs an international training company from Texas, and a large-scale consulting business out of Colorado. You can reach Todd through his forum and blog at www.lammle.com/ccna.

DONALD ROBB has over 15 years of experience with most areas of IT, including networking, security, collaboration, data center, cloud, SDN, and automation/devops. He's earned many advanced certifications and specializations. Currently he's a SDN/Cloud/DevOps SME. Visit his blog at https://www.the-packet-thrower.com and YouTube channel at https://www.youtube.com/c/ThePacketThrower.

JON BUHAGIAR, CCNA, MCSA, MCSE, N+, A+, BS/ITM, is Supervisor of Network Operations at Pittsburgh Technical Institute. In addition to teaching, he has been creating course content for alsmost 20 years. Some of his more recent work can be found on Youtube at http://www.youtube.com/networkedminds.