About the Technical Reviewers

David White, Jr., CCIE No. 12021, has more than 9 years of networking experience with a focus in network security. He is currently a Technical Leader in the Cisco TAC, where he has been for over 5 years. In his role at Cisco, he is involved in new product design and implementation and is an active participant in producing Cisco documentation, both online and in print. David holds a CCIE in Security, and is also NSA IAM certified. Prior to joining Cisco, David worked for the U.S. government, where he helped secure its worldwide communications network. He was born and raised in St. Petersburg, Florida and received his bachelor's degree in computer engineering from the Georgia Institute of Technology.

Andrew Yourtchenko, CCIE No. 5423, is a Customer Support Engineer working in the security area in the Cisco Technical Assistance Centre in Brussels, which he joined in 2000. Born in St. Petersburg, Russia, his first experience with computers was in 1989, which sparked his interest in computers and motivated him to start self-study in computer science while still in school. He graduated St. Petersburg State Technical University in 1997. Andrew's networking experience started around 1992, when he commenced work for a systems integration company in St. Petersburg. In parallel with the job—which varied from fiber cable installations to custom Perl programming—he obtained Novell CNE certification for NetWare 4.1. He became a CCIE in Routing and Switching in 1999 and in Security in 2002.

Wen Zhang, CCIE No. 4302, is a senior engineer in the Cisco TAC Escalation Team, with a focus in network security and VPN technologies. In this role, he is responsible for handling difficult and complex escalation issues, working on critical software defects, and participating in the new product design and implementation process. He earned his B.S. and M.S. degrees in electrical engineering from Clemson University.