This document discusses network security and Cisco's advanced services for network security. It provides an overview of security threats over time, the challenges faced by IT organizations in implementing security, and how an architectural approach to security is required. It describes Cisco's security services across the security lifecycle from assessment to design to implementation. Specific services covered include security posture assessment, network security design review and development. It also discusses best practices for perimeter security, authentication and authorization, and intrusion detection system design.