Finally! Web Filtering That Works in OT Environments

The Trouble with Secure Web Gateways in OT 

Secure web gateways have been around forever. In IT, they are a known solution. You proxy traffic, filter it, and move on.  

But in OT, it’s not so simple. That extra hop is not just inconvenient. It can be dangerous. 

In industrial environments, latency is about much more than user experience. It’s about safety. If an engineer cannot get a vendor update quickly, or if troubleshooting drags because traffic is taking a detour through a distant data center, the issue is no longer about efficiency. Latency creates a window where something can go wrong on the plant floor. 

Connectivity is just as unforgiving. Remote substations, segmented networks, and semi air-gapped environments cannot depend on a permanent link to the cloud. When connectivity drops, so does protection – leaving operations exposed. 

The result is predictable. Some sites open the internet completely and hope for the best. Others block everything and accept the operational dead end. But neither approach is a real solution. 

This is why our team at Cyolo built an on-device secure web gateway (SWG). It delivers the same filtering and protection you expect from a traditional SWG but runs on the device itself. It does not rely on external infrastructure or round-trip connectivity. It simply enforces policy wherever the endpoint happens to be, connected or not. 

How an On-Device SWG Helps OT Teams 

On-device enforcement aligns directly with OT priorities: 

• Low latency equals safety. Engineers access what they need when they need it, which reduces the risk of small issues snowballing into major incidents. 

• Resiliency in low-connectivity environments. Filtering continues even if the WAN link is down. Protection does not rely on someone else’s uptime. 

• Operational simplicity. No fragile network changes or extra infrastructure in the control environment. 

• Consistency. Whether a laptop is at HQ or plugged into a plant network, the same rules apply. 

• Compliance without compromise. Internet access is controlled and logged in a way that satisfies regulators and does not disrupt operations. 

Use Cases on the Plant Floor 

• Contractor laptops. Vendors can securely access documentation and updates without waiting for IT to make risky firewall changes. 

• Operator workstations. Engineers troubleshooting or performing maintenance get access to resources with guardrails in place, without needing the open internet. 

• Mixed IT and OT laptops. Devices that move between corporate and plant networks maintain the same protections everywhere. 

• Air-gapped or semi-connected sites. Even without internet connectivity, policies stay active and enforceable. 

How the On-Device SWG Works in Practice 

The design of Cyolo’s on-device SWG is simple but powerful: 

• Policies are created centrally by IT or OT security teams. 

• Devices download those policies and cache them locally. 

• Enforcement happens on the endpoint itself. Traffic is checked against policy before it leaves the machine. 

• If connectivity to the management plane drops, enforcement does not stop. The device keeps applying the last known policy. 

• Logs are stored locally and sync once connectivity is restored, giving you full audit visibility. 

The bottom line is that security moves with the device, not with the network. In environments where the network is fragile or intentionally segmented, this distinction is everything. 

What Leaders Actually Get Out of Cyolo’s On-Device SWG

Let's be honest. Nobody in OT cares about the latest cloud buzzwords. They care about uptime, safety, and making audits less painful. On device SWG supports those outcomes directly. 

• Faster recovery when things break. Engineers and contractors can get what they need without waiting for IT tickets and firewall exceptions. That shortens mean time to recovery. 

• Lower infection risk. Malicious and phishing sites are blocked before they ever load. That means fewer incidents that could take down a line or a substation. 

• Less infrastructure overhead. No new appliances to rack, no extra choke points to monitor. Security without adding fragility. 

• Predictable user experience. Engineers do not need to guess what works and what does not. The same policies apply everywhere. 

• Audit friendly. Internet access is controlled, logged, and provable, without introducing operational disruption. 

Closing the IT/OT Divide  

The tug of war between IT and OT has always been about tradeoffs. IT pushes for stronger controls, and OT pushes back because those controls risk uptime. Everyone is right, and everyone is frustrated. 

On-device SWG helps change the conversation. Policy enforcement happens on the device itself, which delivers both what IT requires and what OT demands. IT gets consistent controls, while OT keeps the performance and reliability it needs. 

No more false choices between leaving the internet wide open or locking it down completely. No more tradeoffs between uptime and security. Instead, you get a straightforward outcome. Secure, policy driven web access that works anywhere, under any connectivity condition. 

Practical Security Measures for Real-World Environments 

Industrial environments need practical security. They do not need more fragile infrastructure, more moving parts, or more dependence on perfect connectivity. On-device secure web gateway technology delivers filtering and protection exactly where it belongs – at the endpoint. 

For plant managers, that means fewer disruptions. For engineers, it means access to critical resources without exposure. For security teams, it means policy consistency and compliance that does not interfere with operations. 

Security that works with operations, not against them.