As industrial networks can be quite old and widely dispersed, and are sometimes maintained by third-party contractors, organizations often don’t have an accurate inventory of what is on their network. Operations environments are made up of many industrial assets (such as valves, actuators, drives, robots, power breakers, etc.) managed by Industrial Control System (ICS) devices, such as Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), Intelligent Electronic Devices (IEDs), and Distributed Control Systems (DCSs). Without comprehensive and detailed visibility into all these assets, industrial organizations have limited ability to understand cyber risks and build a secure communications architecture.