What is Asset Discovery?
Asset Discovery is the process of identifying, recording and classifying all devices, systems and software present within an IT or OT network. It forms the basis of virtually all cybersecurity measures, because you can only protect what you know about.
In OT environments, asset discovery is essential for gaining visibility into PLCs, SCADA systems, HMIs, field equipment and other embedded components — often distributed across multiple sites and domains.
🧠 Why Asset Discovery is essential
- Inventory – Provides a complete overview of devices, operating systems, firmware and network interfaces
- Risk assessment – Highlights vulnerable or outdated assets that need attention
- Access management – Helps determine who has access to which systems and why
- Monitoring & detection – Foundation for anomaly detection and baseline behaviour
- Management & patching – Supports updates, maintenance planning and lifecycle management
🔍 Asset Discovery methods
| Method | Description |
|---|---|
| Passive network analysis | Monitoring network traffic to recognise devices and protocols |
| Active scanning | Sending queries or pings to actively detect assets |
| Agent-based | Local software collecting information about the system |
| CMDB integration | Linking with existing asset databases or maintenance systems |
| Protocol awareness | Recognition of OT protocols such as Modbus, DNP3, S7 and OPC UA |
In OT, passive discovery is preferred to avoid disrupting sensitive devices.
✅ What is captured during Asset Discovery?
| Attribute | Example value |
|---|---|
| IP and MAC address | 192.168.10.45 – 00:1A:E5:01:23:AF |
| Device type | Siemens S7-1200 PLC |
| Firmware version | v4.3.2 |
| Communication protocol | Profinet, Modbus TCP |
| Physical location | Production line 2, cabinet 3 |
| Serial ports | COM1, RS-485 |
| Last seen | 2025-07-25 10:36 |
🔁 Asset Discovery and related processes
| Process | Relationship to Asset Discovery |
|---|---|
| Patch management | Requires visibility into versions and vulnerabilities per asset |
| Access Control | Restricting access to known and approved systems |
| Monitoring | Asset Discovery provides the basis for detecting anomalies |
| Incident Response | Quickly determining which assets are impacted or vulnerable |
| Backup | The inventory determines which systems need to be backed up |
📦 Asset Discovery in OT vs. IT
| IT | OT |
|---|---|
| Servers, laptops, printers | PLCs, HMIs, RTUs, field components |
| Active scanning via SNMP/WMI | Passive analysis of industrial protocols |
| CMDB or endpoint agent | Integration with Historian, SCADA, CMMS |
| Cloud-native tools | On-premise or network-isolated solutions required |
OT often demands specialised tools that can recognise protocols such as Modbus, S7, DNP3 or OPC UA without affecting the processes.
📌 In summary
Asset Discovery is the foundation of OT Security. Without complete and up-to-date insight into assets, no measure — from patching to access management — can be reliable or effective. In industrial environments, asset discovery must be carried out carefully, safely and continuously.