Title: Design and Implementation of Firewall Policy Advisor Tools
Published: December 2004
Authors: Ehab S. Al-Shaer, Hazem H. Hamed
Abstract: Firewalls are core elements in network security. However, managing firewall rules, especially for enterprise networks, has become complex and error-prone. Firewall filtering rules have to be carefully written and organized in order to correctly implement the security policy. In addition, inserting or modifying a filtering rule requires thorough analysis of the relationship between this rule and other rules in order to determine the proper order of this rule and commit the updates. In this paper, we present a set of techniques and algorithms that provide (1) automatic anomaly detection for discovering rule conflicts and potential problems in legacy firewalls, (2) anomaly-free policy editing for rule insertion, modification and removal, and (3) concise translation of filtering rules to high-level textual description for user visualization and verification. This is implemented in a user-friendly tool called “Firewall Policy Advisor.” The firewall policy advisor significantly simplifies the management of any generic firewall policy written as filtering rules, while minimizing network vulnerability due to firewall rule misconfiguration.
Full Paper: [pdf]