Cisco PIX (Private Internet eXchange) was a popular firewall and network address translation (NAT) appliance. It was one of the first products in this market segment.
In 2005, Cisco introduced the newer Cisco Adaptive Security Appliance (Cisco ASA), that inherited many of the PIX features, and in 2008 announced PIX end-of-sale.
The PIX technology was sold in a blade, the FireWall Services Module (FWSM), for the Cisco Catalyst 6500 switch series and the 7600 Router series, but has reached end of support status as of September 26, 2007.
PIX was originally conceived in early 1994 by John Mayes of Redwood City, California and designed and coded by Brantley Coile of Athens, Georgia. The PIX name is derived from its creators' aim of creating the functional equivalent of an IP PBX to solve the then-emerging registered IP address shortage. At a time when NAT was just being investigated as a viable approach, they wanted to conceal a block or blocks of IP addresses behind a single or multiple registered IP addresses, much as PBXs do for internal phone extensions. When they began, RFC 1597 and RFC 1631 were being discussed, but the now-familiar RFC 1918 had not yet been submitted.
The design, and testing were carried out in 1994 by John Mayes, Brantley Coile and Johnson Wu of Network Translation, Inc., with Brantley Coile being the sole software developer. Beta testing of PIX serial number 000000 was completed and first customer acceptance was on December 21, 1994 at KLA Instruments in San Jose, California. The PIX quickly became one of the leading enterprise firewall products and was awarded the Data Communications Magazine "Hot Product of the Year" award in January 1995.