Abstract

Firewalls are an important tool in the assurance of network security. Packet filtering firewalls are configured by providing a set of rules that identify how to handle individual data packets that arrive at the firewall. In large firewall configurations, conflicts may arise between these rules. Argumentation provides a way of handling conflicts such that their origin is illuminated, and hence can help a system administrator understand the effects of a given configuration. To show how argumentation might help in this domain we examine the use of a system of metalevel argumentation for firewall configuration, showing how it makes conflicts and their origins clear, and showing how different instantiations of a metalevel argumentation system provide alternative ways to resolve conflicts.