Todd Lammle is the Authority on Cisco Certification and Internetworking and is Cisco certified in all Cisco certification categories. He is a world-renowned author, speaker, trainer, and consultant. Todd has three decades of experience working with LANs, WANs, and large enterprise licensed and unlicensed wireless networks, including the implementation of large Cisco Data Centers world-wide. His books draw on his practical experience working on the largest networks in the world at companies such as Xerox, Hughes Aircraft, Texaco, AAA, Cisco and Toshiba. He has published over 60 books, including the very popular CCNA: Cisco Certified Network Associate Study Guide, CCNA Wireless Study Guide, and CCNA Data Center Study Guide, all from Sybex. He runs an international consulting and training company based in Colorado, Texas, and San Francisco. You can reach Todd through his forum and blog at www.lammle.com.