David Bateman, CCNA, is a certified Cisco Systems instructor with more than 18 years of internetworking experience. For more than 10 years, David was a senior LAN/WAN engineer, working on both large and small networks. Later in his career, he managed the business operations of a technical services company while maintaining his existing client base. David has always enjoyed sharing his knowledge, and in 1999, he became a technical seminar leader. After many successful seminars, he became a full-time Cisco instructor for Skyline Advanced Technology Systems. He has been teaching and implementing