The special needs of SCADA/PCN firewalls: architectures and test results

The use of firewalls between business and process control networks is often suggested as an ideal solution for plant floor cyber security. But research shows that few firewalls are properly configured and that many control system security incidents bypass the firewall. If firewalls are to be effective, guidance on how to deploy them in industrial settings is badly needed. The authors conducted a survey exploring the state of the art in industrial firewall deployment. Based on the survey results, four firewalls were configured, using one open-source and three commercial firewall products, and subjected to extensive analysis and testing. While the results indicate that commercial and open-source firewalls can be successfully used, the study also shows important differences between the configuration of firewalls in industrial and IT settings.