Diaz, Llazaro (Laz): - Lazaro (Laz) Diaz, as he prefers to be called, is a Cisco Instructor who has been in both the field and the teaching industry for almost two decades. He currently lives in the State of Florida, USA and migrated from Cuba at the age of six (6) years old. He is a Network Engineer and holds several certifications in CCNA R/S, CCNA Security, CCNA Voice, CCNP, Security+, Network+, A+, MCP, MCTS and the MOS. However, he is best known for his self-paced courses, teaching over 100K students around the globe. His first book is called The Only IP Book You Will Ever Need! However, he knows that this CCNA study guide will be a testament to his commitment in giving students an opportunity to achieve the CCNA R/S certification.