Placement of NPS Across OT Networks

The capability of a Network Passive Sensor (NPS) across an industrial network lies in identifying the critical traffic. It is essential to follow the rule of mirroring the traffic between workstations (EWS, HMI) to controllers (PLCs, RTUs, DCS). Qualys recommends identifying the best path to tap the process data between controllers and workstations and deploying the Network Passive Sensor (NPS) to get the maximum traffic to analyze.