Segmenting IoT and OT Networks: A Practical Guide

Few areas of the modern network are as under-protected — and as attractive to attackers as in IoT and OT (operational technology) environments. Cameras, sensors, industrial controllers, and building management systems often ship with weak security, run outdated firmware that can't be patched easily, and sit on the same network as critical business systems. Innovo Networks treats IoT/OT segmentation as one of the most urgent — and most overlooked — pieces of a Zero Trust strategy.

Why IoT and OT Are Different

Unlike traditional IT endpoints, IoT and OT devices often can't run standard security agents, can't be patched without risking operational downtime, and were frequently designed with connectivity and convenience in mind rather than security. A compromised smart thermostat or industrial sensor might seem like a low risk on its own, but if it sits on the same flat network as finance servers or engineering workstations, it becomes a steppingstone for attackers.

The Segmentation Approach

The goal isn't to make IoT and OT devices secure in isolation — often that's not fully achievable — but to contain them so a compromise can't spread. A practical approach includes:

• Dedicated network zones for IoT and OT traffic, fully separated from corporate IT and business-critical systems.
• Strict, explicit communication rules — IoT and OT devices should only be able to reach the specific systems they need to, and nothing else.
• Outbound restrictions, since many IoT breaches involve devices "calling home" to command-and-control infrastructure.
• Passive monitoring rather than intrusive agents, since many of these devices can't support traditional endpoint security tools.

Common Mistakes

Organizations frequently discover, once they map their network, that IoT and OT devices have far more access than intended — leftover from initial installation, vendor convenience, or simple oversight. Segmentation projects in this space often uncover shadow devices nobody remembered were connected at all.

Bringing OT and IT Together Without Merging Them

As IT and OT environments converge for data analytics and remote management purposes, the temptation is to simply bridge the two networks. Innovo Networks instead recommends carefully brokered connections — data diodes, jump servers, and tightly scoped gateways — that allow the specific data flows needed without collapsing the two environments into one flat, high-risk network.

How Innovo Networks Approaches This

Our team starts with full asset discovery, since IoT and OT visibility gaps are the norm rather than the exception. From there, we design segmentation architectures tailored to the operational realities of each environment — recognizing that a hospital's medical device network has very different constraints than a manufacturing plant's industrial control systems. Zero Trust for IoT and OT aren’t about forcing these devices to behave like IT endpoints; it's about building a network architecture that assumes they won't.