Book excerpt: This complete new guide to auditing network security is an indispensable resource for security, network, and IT professionals, and for the consultants and technology partners who serve them. Cisco network security expert Chris Jackson begins with a thorough overview of the auditing process, including coverage of the latest regulations, compliance issues, and industry best practices. The author then demonstrates how to segment security architectures into domains and measure security effectiveness through a comprehensive systems approach. Network Security Auditing thoroughly covers the use of both commercial and open source tools to assist in auditing and validating security policy assumptions. The book also introduces leading IT governance frameworks such as COBIT, ITIL, and ISO 17799/27001, explaining their values, usages, and effective integrations with Cisco security products.