Special Publication 800-41 Revision 1 Guidelines on Firewalls and Firewall Policy Recommendations of the National Institute of Standards and Technology Karen Scarfone Paul Hoffman Guidelines on Firewalls and Firewall Policy Recommendations of the National Institute of Standards and Technology Karen Scarfone Paul Hoffman NIST Special Publication 800-41 Revision 1 C O M P U T E R S E C U R I T Y Computer Security Division Information Technology Laboratory National Institute of St andards and Technology Gaithersburg, MD 20899-8930 September 2009 U.S. Department of Commerce Gary Locke, Secretary National Institute of Standards and Technology Patrick D. Gallagher, Deputy Director GUIDELINES ON FIREWALLS AND FIREWALL POLICY Reports on Computer Systems Technology The Information Technology Laboratory (ITL) at th e National Institute of Standards and Technology (NIST) promotes the U.S. economy and public welfare by providing technical leadership for the nation’s measurement and standards infrastructure. ITL devel ops tests, test methods, reference data, proof of concept implementations, and technical analysis to advance the development and productive use of information technology. ITL’s responsibilities include the development of technical, physical, administrative, and management standards and guide lines for the cost-effective security and privacy of sensitive unclassified information in Federal computer systems. This Special Publication 800-series reports on ITL’s research, guidance, and outreach efforts in computer security and its collaborative activities with industry, government, and academic organizations. Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment are necessa rily the best available for the purpose. National Institute of Standards and Technology Special Publication 800-41 Revision 1 Natl. Inst. Stand. Technol. Spec. P ubl. 800-41 rev1, 48 pages (Sep. 2009) iiiGUIDELINES ON FIREWALLS AND FIREWALL POLICY Acknowledgments The authors, Karen Scarfone of the National Institu te of Standards and Technology (NIST) and Paul Hoffman of the Virtual Private Network Consortium, wish to thank their colleagues who reviewed drafts of this document and contributed to its technical content. The authors would like to acknowledge Tim Grance, Murugiah Souppaya, Sheila Frankel, and Ga le Richter of NIST, and Matthew Goche, David Klug, Logan Lodge, John Pearce, Noel Richards, A nne Roudabush, and Steven Sharma of Booz Allen Hamilton, for their keen and insightful assistance throughout the development of the document. Special thanks go to Brahim Asfahani of Booz Allen Hamilton for his contributions to early drafts of the document. The authors also thank all the reviewers who provided feedback during the public comment period, particularly Joel Snyder (Opus One), Ron Co lvin (National Aeronautics and Space Administration [NASA]), Dean Farrington (Wells Fargo), Raffael Ma rty (Splunk), and David Newman (Network Test). The authors also wish to express thei r thanks to the individuals and organizations that contributed to the original version of the publication, including John Wack of NIST and Ken Cutler and Jamie Pole of the MIS Training Institute, who authored the original version, and other contributors and reviewers— particularly Peter Batista and Wayne Bavry (U.S. Treasury); Harriet Feldman (Integrated Computer Engineering, Inc.); Rex Sanders (U.S. Geological Survey); and Timothy Grance, D. Richard Kuhn, Peter Mell, Gale Richter, and Murugiah Souppaya (NIST). ivGUIDELINES ON FIREWALLS AND FIREWALL POLIC