Abstract: The invention concerns the field of interconnected computer networks, consisting in a system for generating in a simple and automatic way filters, according to the internet protocol, designed to avoid the risk of breach in interconnected computer networks. A computer terminal and control means interact iteratively with a graphic interface so as to: generate and display the objects and classes requiring security; select and display the application protocols for which filters need to be generated; draw on the graphic interface, by means of arrow curves for each application protocol previously selected, the communication laws. The terminal comprises computing means for converting the graphic data representing the communication laws into programming data for the screening routers.