Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


"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