What is an Industrial Switch?
An Industrial Switch is a network switch specifically designed for industrial environments. Unlike commercial switches, industrial switches are robust against extreme temperatures, vibration, dust and electromagnetic interference (EMI).
Industrial switches form the core of communication networks in the automation layer, such as Control Networks and Supervisory Networks, where reliability and uptime are critical.
🧠 How does an Industrial Switch work?
- Ethernet packet processing
- Sends and receives data frames between network devices (e.g. PLCs, HMIs, IO modules)
- Operates at OSI Layer 2 (data link) or higher (Layer 3 for routing)
- VLAN and segmentation
- Supports VLAN configuration for logical network isolation
- Forms part of the Zone and Conduits model for OT security
- Redundancy support
- Protocols such as RSTP, MRP, PRP, DLR for network redundancy
- Fast recovery on link failure (< 50 ms)
- Security options
- Port Security, 802.1X, ACLs, SNMPv3, QoS
🏭 Application in industrial networks
- Connectivity between field devices and control systems
- Backbone of the Control Network for PLC communication
- Redundant rings in process industry, tunnels, water treatment
- Driving networks with remote I/O or SCADA integration
Typical characteristics:
- DIN-rail or wall mounting
- Temperature range: -40 °C to +75 °C
- IP20, IP30 or IP67 enclosure
- Fanless design for dust-free installations
🔍 Managed vs. Unmanaged Switch
| Feature | Managed Switch | Unmanaged Switch |
|---|---|---|
| Configuration | Yes – via web interface, CLI or SNMP | No – plug & play |
| VLAN support | Yes | No |
| Redundancy protocols | Yes (RSTP, MRP, PRP, DLR) | No |
| Use | Critical OT segments | Simple, non-critical installations |
Managed switches are recommended for OT core networks, while unmanaged are only suitable for simple use cases.
🔐 Security aspects
- Enable Port Security to block unauthorised devices
- Use 802.1X for device and user authentication
- Monitor traffic via SPAN port or TAP
- Integrate with anomaly detection, SIEM and network monitoring
- Configure SNMPv3 for secure management access
Unsecured switches form a point of entry for Insider Threats or malware spread.
📌 In summary
Industrial Switches are robust network components that are essential for reliable, secure and real-time communication in OT networks. They combine physical durability with network management and security functions that are critical for industrial automation.