[Superseded by SP 800-41 Rev. 1 (September 2009): http://www.nist.gov/manuscript-publication-search.cfm?pub_id=901083
] This document provides introductory information about firewalls and firewall policy. It addresses concepts relating to the design selection, deployment, and management of firewalls and firewall environments. It is an update to NIST Special Publication 10, Keeping Your Cite Comfortably Secure: An Introduction To Firewall Technology. This document covers IP filtering with more recently worked policy recommendations, and deals generally with hybrid firewalls that can filter packets and perform application gateway services. This document also contains specific recommendations for policy as well as a simple methodology for creating firewall policy.