U.S. flag   An unofficial archive of your favorite United States government website
Dot gov

Official websites do not use .rip
We are an unofficial archive, replace .rip by .gov in the URL to access the official website. Access our document index here.


We are building a provable archive!
A lock (Dot gov) or https:// don't prove our archive is authentic, only that you securely accessed it. Note that we are working to fix that :)

This is an archive
(replace .gov by .rip)


"A device or program that controls the flow of network traffic between networks or hosts that employ differing security postures." (SP 800-41 Rev. 1)


Created June 08, 2016, Updated June 22, 2020