Automatic Conflict Analysis and Resolution of Traffic Filtering Policy for Firewall and Security Gateway

Firewalls and Security Gateways are core elements in network security infrastructure. As networks and services become more complex, managing access-list rules becomes an error-prone task. Conflicts in a policy can cause holes in security, and can often be hard to find while performing only visual or manual inspection. First, we have defined a methodology to systematically classify the severity of rule conflicts; secondly, we have proposed two different solutions to automatically resolve conflicts in a firewall. For one of them we found an algebraic proof of the existence of the solution and the convergence of the algorithm, and then we have made a software implementation to test it.