Network Security, Firewalls, and VPNs, 3rd Edition

Firewall Enhancements

Firewalls emerged from basic router traffic control systems into full-featured content filters. However, throughout this evolution, firewalls have remained focused on detecting unwanted, unknown, or malicious traffic and blocking it. The filtering mechanisms have typically been identification-based. Whether IP address, port, protocol service, MAC address, content keyword, or even user authentication, the Allow and Deny decisions relied directly on easily definable elements.

Modern firewalls now offer a variety of enhancements, improvements, or add-on features that some organizations might find attractive. You should consider the value of these enhancements in light of the ability of the device to continue to perform ...