Two firewall technologies are prevalent today: the stateful firewall, which provides rudimentary access control based on packet header information, and the application layer firewall, which through deep packet inspection (DPI) and directory service integration enables identity-based access control and security functionality such as intrusion prevention and anti-malware.

NSS has a long history of testing firewall products. Over the years, our group test results have revealed both the expansion of enterprise requirements and the evolution of the technology. This Intelligence Brief provides the NSS perspective on the product category and a history of NSS firewall group test results from 2012 – 2018.