Nozomi Networks built its name on passive, non-intrusive monitoring of OT and ICS networks — visibility and threat detection without touching production traffic. For energy, utility, and manufacturing OT teams where an active scan can trip a controller, "passive first" isn't a marketing line; it's the operational constraint that decides which vendors make the list.
Nozomi taps OT network traffic and builds an asset inventory, communication map, and behavioral baseline without sending packets into the environment. From that baseline it flags anomalies, known threats, and vulnerabilities. The passive-monitoring heritage is the core identity: for OT teams who've watched an active scanner knock a legacy PLC offline, the ability to get deep visibility without injecting traffic is exactly the property they're buying.
Generation, transmission, water, oil & gas where active scanning is off the table. Nozomi's passive-first design is built for this constraint.
Distributed plants needing centralized OT visibility. The sensor-plus-cloud architecture scales across sites without per-plant tool sprawl.
If exposure prioritization and segmentation orchestration are the priority over monitoring, a head-to-head with Claroty is worth running. Compare.
If your decision hinges on adversary-focused ICS threat intel and IR services, Dragos is shaped for that question. Brief Dragos instead.