Abstract: A graphical representation of the firewall and a network coupled to the firewall is generated and displayed. A number of an inbound port of the network is displayed. An arrow adjacent to the port number pointing toward the network is displayed to indicate that a communication is permitted to the port. The port number and the arrow are located between an icon for the network and an icon for the firewall. A port number of a destination of a communication originating from the network is displayed. Also, another arrow adjacent to the destination port number pointing toward the firewall is displayed to indicate that a communication is permitted to the destination port number. The destination port number and the other arrow are located between an icon for the network and an icon for the firewall. A table including definitions of a plurality of rules is generated and displayed. Each of the definitions includes entries for a source IP address and destination IP address of a permitted but vulnerable data flow.