What is a Guest Network?
A guest network is a separate network segment intended for temporary or external users, such as visitors, contractors or suppliers. It provides limited and controlled access to network functionality, without direct access to the internal corporate or production network.
In industrial environments, a guest network is often used to give suppliers, technicians or service personnel access to documentation, maintenance portals or external connections — without putting the OT environment at risk.
🧱 Characteristics of a guest network
| Property | Explanation |
|---|---|
| Network segmentation | Separated from the corporate and production environments (e.g. via VLAN or DMZ) |
| Restricted access | Internet access only or access to specific external services |
| Temporary access | Guest users receive access for a limited period |
| Authentication required | Access often secured with a password, captive portal or certificate |
| No access to OT/IT | Guest users cannot reach critical systems |
🏭 Examples in an industrial context
- A service technician is given internet access to download software
- A supplier uses a guest connection to establish a VPN to their support team
- A technician connects via the guest network to download manuals or Firmware updates
🔒 Why is a guest network important?
- Prevents unauthorised devices from affecting the internal network
- Reduces the risk of Malware, data leaks or unwanted access
- Provides flexibility without compromising the Cybersecurity of OT and IT systems
🔐 In combination with the Zone and Conduits model, a guest network is treated as a separate Zone, with very limited and tightly controlled Conduits to other Zones (typically only via a Jump Server or Firewall).
📌 In summary
A guest network is a secure, isolated network segment that gives temporary users limited access — without putting the internal corporate or production network at risk.