Firewall Policy Modeling, Analysis and Simulation: a Survey

Computer firewalls are widely used for security policy enforcement and access control. Current firewalls use various processing models and are configured using their own policy description languages. In this paper we will try to survey research efforts in the area of formal-ization of firwall operational sematnics and policy description languages and applications of such formal models and languages for firewall simula-tion, policy optimization, detection of configuration errors and enterprise security policy comliance testing. 1 The Scope The range of network security is very broad. It roots in low-level security en-forcement mechanism on the level of IP packets (packet filtering). If we go beyond individual packets analysis, we are now dealing with technique called “stateful inspection”. The next level of network security is high-level enterprise security policies like RBAC [17], and their application to network firewalls[25]. Finally, taking into account network topology, with multiple perimeters of policy enforcement and possbily internal sectioning into security zones, we are now dealing with notion of distributed firwalls and distributed Intrusion Detec-tion Systems (IDS). There is ongoing research in the areas mentioned above. However in this paper, we will deal mostly with the most fundamental level- packet filtering (for broader survey of higher level securitiy-related formal languages and models see [12]). A packet filtering engine lies at the core of most network security mecha-nisms. Having a formal model of this fundamental building block is essential in developement of more complex, higher-level security models