Building Resilient Networks: How VLAN Segmentation Safeguards Industrial Operations

In industrial environments, network design decisions are often made quickly, resulting in flat networks that lack segmentation. While some planning may occur, these networks frequently consist of a single, large subnet and VLAN. We’ll examine the implications of such a design, outline a real-world scenario, and present practical solutions such as VLAN segmentation to enhance network reliability and security.

Defining a Flat Network

A flat network is characterized by all devices residing within a single VLAN—commonly VLAN 1—and sharing at least one IP subnet. While this approach simplifies routing and IP address management, it significantly increases the risk of broadcast storms, which can disrupt operations across the entire network.

Scenario: One Large Subnet

Consider a plant network with one large IP subnet: 10.10.0.0/16, providing 65,534 usable IP addresses. The plant has five lines that rarely communicate with each other but regularly send traffic to servers on the business network. Each line has designated IP addresses for its devices, and there is a router or firewall separating the plant network from the enterprise network.

Below is the network design:

Strengths of a Single Subnet Design

• IP address assignment is planned; each line has designated addresses.
• A router or firewall provides separation between business and production networks.
• A managed switch is used at the top of the network design.

Potential Risks of a Single Subnet Design

• All devices are in the same broadcast domain, meaning a broadcast from any line can impact all others.
• The large subnet allows thousands of unused IP addresses, increasing the risk of unauthorized access or malicious activity.
• Broadcast storms are more likely in larger subnets, potentially causing network-wide disruptions.

The Solution: VLAN Segmentation

Network segmentation is recommended. Assigning a unique VLAN to each line confines broadcast traffic within its respective segment, minimizing the risk of network-wide disruptions. This approach leverages the existing IP address planning and enhances both security and performance.

Now broadcast traffic looks like this:

Boost Industrial Security

Segmenting your network is a practical way to boost both security and reliability in industrial environments. Moving from one large subnet to smaller, dedicated VLANs help contain broadcast traffic and reduces the risk of downtime or unauthorized access. While a flat network may seem simpler at first, dividing your plant into logical segments makes troubleshooting easier and protects your operations from potential threats. The right approach depends on your plant’s needs and existing infrastructure, but taking steps to organize your network will help keep your systems safe and your business running smoothly.

Strengthen your plant’s operations with effective network segmentation. Contact Kendall Electric’s Network Specialists for tailored solutions that keep your facility secure and running smoothly.