Greg Tomsho is director of the Computer Networking Technology Department and Cisco Academy at Yavapai College in Prescott, Ariz. He has earned the CCNA, MCTS, MCSA, A+, Security+ and Linux+ certifications. A former software engineer, technical support manager and IT director, he has more than 30 years of computer and networking experience. His other books include MCTS GUIDE TO WINDOWS SERVER 2008 ACTIVE DIRECTORY CONFIGURATION, MCTS GUIDE TO MICROSOFT WINDOWS SERVER 2008 APPLICATIONS INFRASTRUCTURE CONFIGURATION, GUIDE TO NETWORKING ESSENTIALS, GUIDE TO NETWORK SUPPORT AND TROUBLESHOOTING and A+ COURSEPREP EXAMGUIDE.