Localizing Security for Distributed Firewalls

In complex networks, filters may be applied at different nodes to control how packets flow. In this paper, we study how to locate filtering functionality within a network. We show how to enforce a set of security goals while allowing maximal service subject to the security constraints. Our contributions include a way to specify security goals for how packets traverse the network and an algorithm to distribute filtering functionality to different nodes in the network to enforce a given set of security goals.