Diane Teare, P.Eng, CCNP, CCDP, CCSI, PMP, is a professional in the networking, training, project management, and e-learning fields. She has more than 25 years of experience in designing, implementing, and troubleshooting network hardware and software, and has been involved in teaching, course design, and project management. She has extensive knowledge of network design and routing technologies. Diane is a Cisco Certified Systems Instructor (CCSI), and holds her Cisco Certified Network Professional (CCNP), Cisco Certified Design Professional (CCDP), and Project Management Professional (PMP) certifications. She is an instructor, and the Course Director for the CCNA and CCNP Routing and Switching curriculum, with one of the largest authorized Cisco Learning Partners. She was the director of e-learning for the same company, where she was responsible for planning and supporting all the company's e-learning offerings in Canada, including Cisco courses. Diane has a bachelor's degree in applied science in electrical engineering and a master's degree in applied science in management science. She authored or co-authored the following Cisco Press titles: the first edition of this book; the second edition of Designing Cisco Network Service Architectures (ARCH); Campus Network Design Fundamentals; the three editions of Authorized Self-Study Guide Building Scalable Cisco Internetworks (BSCI); and Building Scalable Cisco Networks. Diane edited the first two editions of the Authorized Self-Study Guide Designing for Cisco Internetwork Solutions (DESGN), and Designing Cisco Networks. Bob Vachon, is a professor at Cambrian College in Sudbury, Ontario, Canada, where he teaches Cisco networking infrastructure courses. He has more than 30 years of work and teaching experience in the computer networking and information technology field. Since 2001, Bob has collaborated as team lead, lead author, and subject matter expert on various CCNA, CCNA-S, and CCNP projects for Cisco and the Cisco Networking Academy. He also was a contributing author for the Routing Protocols Companion Guide, Connecting Networks Companion Guide, and authored the CCNA Security (640-554) Portable Command Guide. In his downtime, Bob enjoys playing the guitar, playing pool, and either working in his gardens or white-water canoe tripping. Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. Rick has worked and taught in the computer networking and information technology field for almost 30 years. Before teaching, Rick worked in IT for various companies, including Santa Cruz Operation, Tandem Computers, and Lockheed Missiles and Space Corporation. He holds a Master of Arts degree in computer science and systems theory from California State University Monterey Bay. Rick also works for the Cisco Networking Academy Curriculum Engineering team and has written other books for Cisco Press, including IPv6 Fundamentals. When Rick is not working, he is most likely surfing. Rick is an avid surfer who enjoys surfing at his favorite Santa Cruz breaks.