What are zones and conduits?

Zones and conduits are cybersecurity concepts defined in the IEC 62443 standard for industrial control systems (ICS). A zone is a logical or physical grouping of assets that share similar security requirements, while a conduit is the controlled communication path that connects two or more zones. Together, zones and conduits improve network segmentation, reduce cyber risk, and help organizations control how data and traffic move between critical systems.

Why Are Zones and Conduits Important?

Industrial and operational technology (OT) networks often contain devices with different functions, risk levels, and security requirements. When all systems operate on a single flat network, a security incident can have a much broader impact.

By implementing zones and conduits, organizations can:

• Group assets with similar security requirements.
• Control and monitor communication between network segments.
• Apply security policies more precisely.
• Reduce the risk of unauthorized lateral movement across the environment.
• Improve visibility into network traffic and access patterns.

This approach is a core principle of the IEC 62443 framework and helps organizations build more resilient industrial networks.

Zones and Conduits in Practice

A common example is an industrial environment that separates business systems from operational technology systems.

• Enterprise Zone: Email, ERP platforms, databases, and business applications.
• Control Zone: PLCs, HMIs, SCADA systems, and other operational technology devices.
• Conduit: A firewall-protected communication channel that allows only approved traffic between the two zones.

Instead of allowing unrestricted communication, conduits enforce security policies and provide a controlled pathway for data exchange. This design supports the principle of least privilege by allowing communication only through managed and authorized channels.

Hexnode Pro Tip

While IEC 62443 focuses on securing communication between network segments, organizations also need visibility and control over the endpoints that access those networks. Hexnode UEM helps IT teams manage devices, enforce compliance policies, monitor endpoint security, and control access across distributed device fleets from a centralized console. Combining endpoint management with network segmentation strengthens an organization’s overall security strategy.

Key Takeaway:

Zones and conduits strengthen cybersecurity by separating assets based on their security requirements and controlling communication between network segments. This structured approach reduces the attack surface and helps prevent unauthorized lateral movement across critical systems. It also enables organizations to apply security policies more effectively and maintain greater visibility into network traffic. As a result, businesses can reduce cyber risk and limit the impact of potential security incidents.