Physical Network Governance for Operational Technology

Industrial control systems, SCADA networks, and manufacturing processes were built for reliability, not cybersecurity. As IT/OT convergence accelerates, these systems face threats they were never designed to withstand.

Zero

IT-to-OT crossover pathways

24/7

Operational continuity maintained

9

Governance modules for OT isolation

Full

IEC 62443 compliance evidence

"We had a firewall between IT and OT. We thought that was an air gap. When the ransomware jumped across, we realised a firewall rule is just software, and software can be bypassed. We needed physical disconnection."

Where each module is deployed, and what it does there.

One row per module. Placement on the network, then plain-English purpose at that point.

1. Isolate

   At every Purdue boundary

   Each layer sits on its own physical fabric. A compromise in enterprise cannot walk into process control or safety on the strength of a misconfigured rule.

2. Firebreak

   On the L5 to L4 link and the L4 to L3.5 link

   Firebreak gives the OT team a real hardware off switch on the IT boundary, so a compromise in enterprise cannot ride a live cable into process control.

3. Relay

   Inside the L3.5 DMZ

   Data moves from enterprise into OT through scheduled, defined routes. Nothing streams unattended.

4. Validate

   Inside the L3.5 DMZ

   Before anything reaches process control, Validate checks its origin, integrity and authority.

5. Transfer

   Inside the L3.5 DMZ

   When data has to move across the boundary, Transfer governs how it crosses and where it lands.

6. Execute

   On the L2 to L1 link

   Pushing a change to a controller holds until the right approval is in place.

7. Lock

   On the L1 to SIS link and the SIS to L0 link

   Safety is the last layer anything reaches. Lock ties that boundary to named operators with the right engineering authority.

PLC & SCADA Config Protection

Golden copies of PLC programs, SCADA configurations, and HMI settings stored in hardware-encrypted offline vaults, immune to network-based attacks.

Historian Backup

Process historian data protected in physically disconnected storage, ensuring operational records survive ransomware and are available for safety investigations.

Controlled Maintenance Windows

Time-bound access windows for firmware updates and configuration changes, physical paths open only during authorised periods with full audit trails.

IEC 62443 Evidence

Automated compliance logging maps to IEC 62443 zone and conduit requirements, demonstrable physical separation, not just logical segmentation.

Zero-Downtime Deployment

Deploys alongside existing OT infrastructure without requiring changes to PLCs, SCADA systems, or network architecture, no production disruption.

OT Environment Audit

Map all IT/OT boundaries, shared network paths, historian connections, and remote access points to identify where physical separation is required.

Zone and Conduit Design

Align Control modules to IEC 62443 security zones and conduits, designing physical separation that maps directly to your compliance requirements.

Non-Disruptive Pilot

Deploy alongside existing PLCs, SCADA systems, and RTUs without any changes to operational equipment, zero production downtime during validation.

Production Go-Live

Activate controlled maintenance windows, historian backup replication, and immutable audit trails across your entire OT environment.