What is VLAN Tagging?

VLAN Tagging is a method used to identify and separate network traffic in Virtual Local Area Networks (VLANs). Defined by the IEEE 802.1Q standard, VLAN tagging adds a VLAN ID to Ethernet frames allowing network switches to differentiate traffic from multiple VLANs on a single physical connection. VLAN tagging improves network organization, security, and performance by isolating devices into separate logical networks. It is commonly used in industrial automation to segment traffic between HMI, PLC, and other devices.

Example Scenario: VLANs SCADA System:

In a SCADA system, VLAN Tagging separates traffic between HMI, PLC, and other devices to ensure proper isolation. The HMI and PLC are placed in different VLANs to avoid interference from other non-critical traffic. Additionally it allows the network switch to assign the appropriate VLAN ID to each packet, ensuring it reaches the correct destination. This improves network performance, security, and ensures SCADA data is prioritized over less critical traffic, reducing the risk of interference.

Content created by Mike Day