Discovery tools are software utilities that automatically find and inventory network resources. They scan IP ranges, identify active devices, open ports, running services, and installed software.
For an ISMS, discovery tools are essential: you can only protect what you know about. Tools like Nmap, Lansweeper, or Qualys VMDR provide the foundation for an up-to-date asset inventory (ISO 27001, A.5.9). Regular scans reveal shadow IT — devices and services operated without the IT department’s knowledge. The results feed into risk assessments and vulnerability management.