A preparation guide for the Cisco certified internet expert (CCIE) security written exam 350-018 and recertification exam 350-009 that demonstrate mastery of the networking concepts and security skills necessary to build a complex, secure, and routable IP network using Cisco routers. It reviews routing protocols, the domain name system, TFTP file transfers, hardware components, access lists, encryption technologies, Windows and Unix, packet filtering, and the intrusion detection system