Measuring the Usability of Firewall Rule Sets

Firewalls are computer systems that assess the network traffic using an ideally coherent and manageable set of rules. This study aims to provide means to measure the usability of firewall rule sets in terms of how easily IT professionals can understand and manage them. First, we conducted semi-structured interviews with system administrators wherein we obtained the usability challenges related to the management of firewall rule sets. This was followed by the analysis of related work. The interview results were combined with the findings from the related work. Accordingly, we acquired four usability attributes related to the manageability of firewalls; these were formally defined. We tested and measured the cognitive aspects related to the structure and ordering of the rules through a user study. A third user study with system administrators validated our metrics. It exhibited a very strong correlation between the metrics and how the administrators characterized usability.