Towards Optimal Firewall Rule Ordering Utilizing Directed Acyclical Graphs
Source: Wake Forest University
Firewalls enforce a security policy by inspecting packets arriving or departing a network. This is often accomplished by sequentially comparing the policy rules with the header of an arriving packet until the first match is found. This process becomes time consuming as policies become larger and more complex. Therefore determining the appropriate action for arriving packets must be done as quickly as possible.