- Look for a firewall that provides stateful inspection. Most have this capability. Representative of an advanced firewall architecture, it keeps track of communication packets and ensures that you can easily allow return traffic corresponding to your outbound requests. Only incoming packets that constitute a proper response are allowed through the firewall.
- Consider if you need content filtering. Do you want to take measures to protect users on the network from accidentally (or intentionally!) browsing websites that contain malicious or offensive content? Some firewalls offer content-filtering capabilities.
- How long can you be down? If the firewall fails, what's your backup plan? More expensive firewalls have high-availability configurations that allow the use of two devices. If the primary one fails, the secondary firewall automatically takes over. For those making do with a less expensive product, consider purchasing a second device that can be kept on the shelf for use in the event of a failure.
This was first published in December 2008