David Groth is a full-time author and consultant. He is the author of the Sybex's bestselling Network+ Study Guide as well as I-Net+ Study Guide and Cabling: The Complete Guide to Network Wiring. Groth holds many technical certifications, including A+, Network+, Server+, Security+, MCSE, and CNI. Ron Gilster (CCNA, CCSE, i-Net+, Network+, A+, MBA, and AAGG) has been involved with Cisco networking and internetworking since 1993 as a trainer, teacher, developer, merchant, and end user. He has more than 35 years of total computing experience, including more than 15 years involved with the networking of computers. He also has extensive experience consulting in computer-related areas, including working on mainframes, minicomputers, and virtually every type of personal computer and operating system that exists. He has held consulting and management positions with several high profile companies. Ron is semi-retired, writing and teaching the occasional college course. He is the author of CCDA For Dummies, Cisco Networking For Dummies, A+ Certification For Dummies, Network+ Certification For Dummies, Server+ Certification For Dummies, and i-Net+ Certification For Dummies, plus several books on networking, including wireless networking, the Internet, computer hardware, computer and information literacy, and programming. Megan Miller is an editor and writer with 20 years experience in publishing, technical project management, and interactive communications.