The Value of VLAN in Industrial IoT: From Concept and Application to Wavetel IoT Practical Solutions

Table of contents（Click to go to where you want to see）

1. Definition of VLAN

2. Types of VLAN

3. Main functions of VLAN in industrial routers

4. Comparative analysis

5. Best practices for implementing industrial VLAN

6. Future outlook: Evolution of VLAN in Industry 5.0

Introduction: New Requirements for Industrial Networks

Driven by Industry 4.0 and smart manufacturing, the Industrial Internet of Things (IIoT) has placed unprecedented demands on network architecture. The number of devices in factory environments has skyrocketed, including sensors, programmable logic controllers (PLCs), industrial robots, monitoring systems, and more. The data streams generated by these devices are complex and diverse. Traditional flat network architectures, lacking segmentation and isolation mechanisms, are prone to broadcast storms, performance bottlenecks, and security risks, failing to meet the modern industrial environment's demands for high reliability, low latency, and high security. Virtual Local Area Network (VLAN) technology optimizes network management through logical segmentation, becoming a core solution in industrial network design. As a leading provider of industrial network equipment, Wavetel IoT's industrial routers, gateways, modems, and switches (such as the WR575 5G router, WR244, and WR565 series) are deeply integrated with VLAN technology, supporting complex network requirements across sectors including energy, security, automotive, environmental protection, and smart manufacturing. This article will provide a detailed exploration of VLAN definitions, types, specific applications in industrial routers, comparative analysis, best practices, and future development trends.

1. Definition of VLAN

A Virtual Local Area Network (VLAN) is a network segmentation technology based on the IEEE 802.1Q standard. It creates logical segments on a physical local area network to group devices into independent broadcast domains without the need for additional physical hardware. VLANs identify the virtual network to which a data frame belongs by assigning tags (VLAN tags) to switch ports, thereby achieving traffic isolation, reducing broadcast storms, and improving network performance. In industrial IoT environments, VLANs can efficiently manage complex data flows from a large number of devices. For example, in a smart factory, VLANs can separate sensor and PLC data from production lines from IT traffic in management offices, ensuring priority transmission for critical production tasks while reducing the risk of network congestion. Additionally, VLANs support flexible network configurations, allowing administrators to dynamically adjust network structures based on device functionality, departmental needs, or security requirements.

2. Types of VLANs

In industrial IoT, different types of VLANs meet diverse network requirements. The following are common types of VLANs and their specific applications in industrial scenarios:

• Default VLAN

The default VLAN is the initial configuration of the switch when it leaves the factory, typically VLAN 1, with all ports belonging to this VLAN by default. The default VLAN is suitable for basic network connections, but due to its lack of isolation functionality, it should be used with caution in industrial environments. For example, in a small factory, the default VLAN can be used for temporary connections to test equipment, but in a production environment, a dedicated VLAN should be configured to ensure security.

• Data VLAN

  The data VLAN is specifically designed to carry data traffic from industrial devices (such as sensors, PLCs, and industrial cameras), effectively isolating production-related traffic. For example, in an automotive manufacturing plant, the data VLAN can be used to transmit real-time data from welding robots and quality inspection equipment, avoiding bandwidth competition with non-production traffic.

• Voice VLAN

The voice VLAN is specifically designed for VoIP (Voice over IP) traffic, combining Quality of Service (QoS) mechanisms to ensure low latency and high-quality voice transmission. In industrial scenarios, the voice VLAN is suitable for remote monitoring or real-time communication between operators. For example, in remote pump stations in the energy industry, voice VLANs ensure stable communication between on-site engineers and the control center.

• Management VLAN

Management VLANs are specifically used for network device configuration and monitoring traffic, supporting protocols such as SSH, SNMP, and Telnet. Isolating management traffic prevents unauthorized access and improves network management efficiency. For example, in the environmental protection field, management VLANs can be used for remote configuration and monitoring of data acquisition devices for air quality sensors.

• Local VLAN

Local VLANs handle untagged traffic on trunk ports and are typically used for communication between switches. In multi-switch industrial environments, local VLANs ensure data consistency across devices. For example, in large logistics warehouses, local VLANs can be used to connect switches distributed across different areas.

• Trunk VLAN

Trunk VLANs allow traffic from multiple VLANs to be transmitted over a single link, suitable for industrial scenarios requiring connections between multiple switches. For example, in a smart manufacturing factory, Trunk VLANs can interconnect VLAN traffic from production lines, warehouses, and office areas through a core switch.

• Private VLAN (PVLAN)

Private VLAN enhances security by further isolating device ports within the same broadcast domain. In industrial data centers, PVLAN prevents direct communication between servers. For example, in SCADA systems in the energy industry, PVLAN can isolate different monitoring nodes to reduce the risk of network attacks.

• Static VLAN

Static VLANs manually assign ports to specific VLANs, making them suitable for fixed devices such as PLCs or industrial control panels. Static VLANs are easy to configure and ideal for industrial environments where device locations and functions are fixed.

• Dynamic VLAN

Dynamic VLANs automatically assign VLANs based on MAC addresses, protocols, or user authentication, making them suitable for scenarios where devices frequently move. For example, in smart logistics, automated guided vehicles (AGVs) can dynamically switch VLANs across different zones to maintain network connectivity flexibility.

These VLAN types provide flexible networking solutions for industrial networks. For instance, management VLANs isolate monitoring traffic, dynamic VLANs accommodate mobile devices, and private VLANs enhance protection for sensitive data.

3. The primary role of LAN in industrial routers

VLAN technology plays a key role in industrial routers, significantly improving network performance, security, and management efficiency. The following are the five core functions of VLAN in industrial routers, combined with specific applications of Wavetel IoT products:

• Network segmentation and traffic isolation

VLAN achieves network segmentation by dividing the network into multiple logical broadcast domains, thereby reducing broadcast storms and optimizing bandwidth allocation. In industrial environments, there are numerous types of devices (such as sensors, PLCs, industrial cameras, and HMIs), and the data flow requirements of different devices vary significantly. VLAN can assign production equipment (such as PLCs and sensors on production lines) to one VLAN and management equipment (such as office computers) to another VLAN, thereby preventing traffic conflicts. For example, Wavetel IoT's WR575 5G industrial router supports the IEEE 802.1Q VLAN protocol and integrates network protocols such as TCP, UDP, DHCP, and NAT, allowing users to quickly configure VLANs in industrial environments via a web GUI or CLI. For instance, in an automotive manufacturing plant, the WR575 can separate sensor data from the stamping workshop from control traffic in the assembly workshop, ensuring efficient transmission of real-time production data.

• Enhancing Security

Industrial networks face growing threats from cyberattacks, such as malware propagation or unauthorized device access. VLANs prevent lateral communication between devices through logical isolation, thereby reducing security risks. Private VLANs (PVLANs) further isolate ports within the same broadcast domain, making them particularly suitable for data centers or shared network environments. For example, in the energy industry's smart grid, PVLANs can isolate monitoring devices from control devices in substations to prevent potential network intrusions. Wavetel IoT's industrial routers (such as the WR575 and WR244) integrate firewall, DMZ, Anti-DDOS, and VLAN security features to provide multi-layered protection for sensitive industrial data. For example, in the environmental protection sector, VLANs can isolate water quality monitoring sensors from external networks to prevent data tampering or leakage.

• Support for QoS and priority management

VLANs combined with Quality of Service (QoS) mechanisms can allocate higher bandwidth and priority to critical tasks. Voice VLANs and data VLANs optimize the transmission of VoIP and real-time data traffic, respectively, ensuring low latency and high reliability. For example, in the automotive industry's remote diagnostic systems, voice VLANs prioritize voice communications between engineers and control centers, while data VLANs ensure the real-time transmission of diagnostic data. Wavetel IoT's WR575 router supports Wi-Fi 6 and multi-WAN failover functionality, working in tandem with VLAN to provide low-latency and high-reliability network connectivity. Although the WR575 does not explicitly support QoS configuration, its high-performance hardware and flexible protocol stack provide a solid foundation for VLAN priority management. For example, in intelligent transportation systems, the WR575 can isolate traffic signal control data from video surveillance traffic via VLAN, ensuring the real-time nature of signal control.

• Flexibility and Scalability

VLAN technology reduces reliance on physical network devices through logical segmentation, making industrial networks easier to scale. Dynamic VLANs automatically assign devices based on MAC addresses or authentication, suitable for scenarios with frequent device movement, such as AGVs or warehouse robots in smart logistics. Trunk VLANs allow multiple VLANs to be transmitted over a single link, facilitating industrial routers' connection to distributed switches. Wavetel IoT's WR244 and WR565 industrial routers offer multiple Ethernet ports and cellular connectivity (4G/5G), supporting advanced routing protocols such as static routing, BGP, OSPF, and RIP, and seamlessly integrating with VLANs for network expansion. For example, in a large petrochemical plant, the WR244 can connect switches in the refining area and warehouse area via Trunk VLAN, enabling unified network management across regions.

• Management and Monitoring

The management VLAN is dedicated to device configuration and monitoring traffic, supporting management protocols such as SSH, SNMP, Telnet, and Web GUI. Isolating management traffic prevents unauthorized access and improves operational efficiency. Wavetel IoT's industrial routers provide an intuitive management interface via Web GUI and CLI, and when combined with the management VLAN, effectively isolate configuration traffic. For example, in a remote air quality monitoring system in the environmental protection field, the management VLAN allows engineers to remotely configure sensor parameters via the WR565 router without physical access to the device. Additionally, Wavetel's SNMP support facilitates integration into network management systems (such as Nagios or Zabbix) for real-time monitoring and fault diagnosis.

4. Comparative Analysis

   
   

   Industrial Networks with and without VLANs

Networks with VLANs are more suitable for complex, multi-device scenarios in industrial environments. For example, in smart manufacturing factories, VLANs can isolate production lines, warehouses, and office networks, ensuring efficient transmission and security of production data.

Static VLAN vs Dynamic VLAN

Static VLANs offer higher control and stability, suitable for industrial scenarios with fixed devices; dynamic VLANs are more suitable for applications with high mobility. For example, in a logistics warehouse, static VLANs can be used for fixed scanning devices, while dynamic VLANs adapt to the dynamic connection requirements of AGVs. 

VLAN vs Subnet

VLAN is more suitable for industrial scenarios requiring low latency, high security, and flexible networking. For example, in smart factories, VLAN can quickly isolate traffic from different production lines, while subnets are more suitable for cross-regional network planning.

5. Best Practices for Implementing Industrial VLANs

5.1 Planning Principles

• Divide VLANs based on function rather than location: Divide VLANs according to device function (such as production, monitoring, management) rather than simply by geographical location. For example, in a smart factory, production line PLCs, sensors, and HMIs can be assigned to the “production VLAN,” while monitoring devices can be assigned to the “monitoring VLAN.”

• Reserve VLAN IDs for future expansion: Reserve 20–30% of VLAN IDs (e.g., VLAN 100–200) during planning to accommodate new devices or departments. For example, in the energy sector, newly added smart meters can be assigned to reserved VLAN IDs.

• Use independent VLANs for critical devices: Assign critical devices (such as SCADA systems or security monitoring devices) to dedicated VLANs and combine them with access control lists (ACLs) to restrict access. For example, in a petrochemical plant, the SCADA system should use an independent VLAN 10.

• Establish clear VLAN naming conventions: Use descriptive names such as “VLAN_Production_101” or “VLAN_Management_200” for easier management and troubleshooting.

  
  

5.2 Configuration Recommendations

• Limit the use of the default VLAN: Disable VLAN 1 or restrict it to non-critical traffic to avoid security risks. For example, move all production equipment to a custom VLAN (such as VLAN 100).

• Enable VLAN pruning: Reduce bandwidth consumption on trunk links by pruning unnecessary VLAN traffic. For example, in a multi-switch environment, restrict irrelevant VLAN traffic from being transmitted to edge switches.

• Optimize critical business operations with QoS policies: Configure high priority for voice VLANs or real-time data VLANs to ensure low latency. For example, in remote monitoring, the priority of voice VLANs should be higher than that of regular data VLANs.

• Regularly review VLAN configurations: Monthly checks of VLAN assignments and access policies ensure no redundancy or misconfigurations. Wavetel IoT devices support configuration backup and restore functions, facilitating quick fixes for configuration errors.

  
  

5.3 Common Issue Resolution

• VLAN-to-VLAN communication issues: Configure VLAN-to-VLAN routing via a Layer 3 switch or router, and use ACLs to restrict communication. For example, in a smart factory, limited communication between production line VLANs and management VLANs can be achieved via a router.

• Performance bottlenecks: Check if VLANs span too many switches causing latency, and optimize trunk link configurations. For example, ensure core switches have sufficient trunk port bandwidth.

• Configuration errors: Use Wavetel IoT routers' configuration backup feature to regularly save VLAN configurations and quickly restore them when errors occur. For example, the WR575 supports one-click restore functionality to minimize downtime.

6. Future Outlook: The Evolution of VLANs in Industry 5.0

As the industrial internet evolves toward Industry 5.0, VLAN technology will continue to develop in the following areas to support smarter, more dynamic industrial networks:

• Integration with Time-Sensitive Networks (TSN): VLANs will be combined with TSN to support deterministic network transmission, meeting Industry 5.0's demand for ultra-low latency. For example, in collaborative robot systems, TSN and VLAN can ensure the priority transmission of real-time control data.

• Support for more dynamic VLAN allocation: Dynamic VLAN allocation based on AI and machine learning will be more widely adopted, automatically adapting to changes in devices. For example, future smart factories can dynamically adjust VLAN configurations based on production tasks.

• AI-driven VLAN automatic optimization: AI algorithms will analyze network traffic patterns to automatically optimize VLAN segmentation and QoS settings. For example, in logistics warehouses, AI can adjust dynamic VLAN allocation based on AGV movement patterns.

• Synergy with 5G industrial private networks: VLAN will be deeply integrated with 5G private networks to provide high-bandwidth, low-latency wireless industrial networks. For example, in large factories, 5G and VLAN can support cross-regional mobile device connections.

  
  

Wavetel IoT is actively investing in R&D to ensure that its industrial routers and switches support next-generation VLAN technology. For example, the WR575 series already supports 5G and Wi-Fi 6, laying the foundation for future TSN and dynamic VLAN applications.

Conclusion

VLAN technology provides efficient, reliable, and flexible network solutions for industrial IoT through network segmentation, traffic isolation, and enhanced security. Wavetel IoT's industrial routers (such as the WR575, WR244, and WR565) seamlessly integrate with VLAN technology to support complex network requirements in industries such as smart manufacturing, energy, automotive, and environmental protection. By properly planning and configuring VLANs, industrial enterprises can significantly enhance network performance, security, and scalability. For more information about Wavetel IoT products and VLAN applications, please visit https://www.waveteliot.com/.