Forescout combines network access control with OT and IoT visibility — its long heritage is agentless discovery plus the ability to enforce: segment, quarantine, and control devices on the network, not just inventory them. For organizations that need NAC and OT/IoT visibility under one roof rather than two separate buys, Forescout's see-and-control posture is the reason it's on the list.
Forescout discovers and classifies devices as they connect — managed, unmanaged, IoT, and OT — without agents, then applies policy: network segmentation, access enforcement, and automated response. The differentiator versus pure-visibility tools is the control plane: Forescout doesn't just tell you a rogue device joined, it can act on it. For teams who want one platform that both sees the device estate and enforces access, that combination is the value.
If you'd otherwise buy a NAC tool and a device-visibility tool separately, Forescout's combined see-and-control platform is built for exactly this.
Teams that need to quarantine and segment devices automatically. The control plane is the differentiator over visibility-only tools.
If discovery breadth across every device class is the priority over enforcement, Armis's visibility-first design may fit tighter. Worth comparing.
If you want non-intrusive OT monitoring with no NAC angle, Nozomi's passive-first design is shaped for that. Brief Nozomi instead.