Guide to Network Defense and Countermeasures, 2E is the second of two books that are required for Level One of the Security Certified Program (SCP). This edition has been revised with updated content and maps clearly to the exam objectives for the current Security Certified Network Professional (SCNP) exam. Although the primary emphasis is on intrusion detection, the book also covers such essential practices as developing a security policy and then implementing that policy by performing Network Address Translation, setting up packet filtering, and installing proxy servers, firewalls, and virtual private networks.