The concept of the NGFW was introduced a decade ago by Gartner. According to Gartner, NGFWs are “deep-packet inspection firewalls that move beyond port/protocol inspection and blocking to add application-level inspection, intrusion prevention, and bringing intelligence from outside the firewall.”

Traditional firewalls operated at Level 3 and Level 4, and allowed or blocked traffic based on port and protocol, leveraged stateful inspection, and made decisions based upon defined policies. As attacks evolved and became more sophisticated, attackers were able to bypass the stateful inspection firewalls, making enhanced security more critical.