Lots of companies still rely on firewalls to safeguard their industrial control system. Nevertheless, firewalls are insufficient for safeguarding an OT network from unknown threats, technical errors states and sabotage. Regarding the growing IT/OT-convergence in industrial networks, it is necessary to have a solution, that looks inside the black box of the network ecosystem. Klaus Mochalski, CEO Rhebo, explains in this Video Blog the integrative approach how to use an OT monitoring system complementary with a firewall and ultimately increase the cybersecurity of an ICS.