Firewalls have been a staple of network security for decades, sitting at the perimeter of an organization’s network and using stateful filters to decide which connections to allow in and out of the network. However, modern organizations operate in a profoundly different landscape. The perimeter is no longer easy to define; organizations are more diverse, users are spread out geographically, infrastructure is deployed in multiple locations, connectivity offerings change, bandwidth capability continues to grow—and, of course, the security threat posed to business is more complex than ever.

All of this makes an enterprise firewall a requirement for just about all organizations. However, selecting an appropriate solution can be difficult. Firewalls work at the network layer, and this influences how they are evaluated, requiring an additional focus on performance, flexibility, and scalability, as well as on core features.