See who talks to whom on your network. Production keeps running.
Trout Access Gate is an on-premise appliance that monitors your OT network. It watches the traffic already there and shows who talks to whom and what changes, with no scanning and nothing installed.
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| IP Address | Name | Type | Traffic |
|---|---|---|---|
| 172.31.115.246 | Admin Access HTTP | ASSET | 500.43Mb |
| 172.31.112.2 | Temperature Sensor | ASSET | 250.36Mb |
| 10.0.4.18 | PLC Controller #3 | OT | 84.12Mb |
You cannot secure what you cannot see.
Most OT operators cannot say which machines talk to which. Devices were added over decades by different integrators, and traffic between machines inside the plant goes unwatched.
The usual way to find out, active scanning, is the one thing OT cannot tolerate. Probing a sensitive PLC or RTU can crash it, and a vulnerability scanner sweeping a control network generates exactly the kind of unexpected traffic that trips safety systems.
Watching the traffic that already crosses the network shows who talks to whom, how much, and when that changes, with no packets sent and nothing installed. The list of machines itself lives in the OT asset inventory, built from the same traffic.
Accurate visibility, without risk to production.
Access Gate learns your network by watching it. You can trust the picture from day one.
It watches, it never probes.
It sees traffic without touching machines or disturbing operations.
It uses the telemetry you have.
It reads NetFlow from your router or firewall, or raw traffic from a mirrored switch port.
It flags what changes.
A change against the baseline raises an alert.
It reads protocols from a packet capture.
NetFlow shows who, which ports, how much and when. A packet capture adds the protocol details.
It shows who talks to whom.
It maps every flow, including traffic between machines inside the plant.
It runs on the appliance.
Analysis runs on site, with no extra servers.
Visibility from day one, with no production impact.
Start by watching the traffic.
Send NetFlow from the router or firewall you already have to Access Gate, or mirror a switch port to it. It starts mapping flows right away, with no agents, no probes, and no traffic added to the OT network.
Turn visibility into control.
The flows it sees and the machines in the asset inventory become the basis for zones, conduits, and access rules, so what you watched turns directly into segmentation and least-privilege access.
Monitoring evidence for NIST, CMMC, and IEC 62443.
Auditors start from the asset list. The asset inventory builds and keeps that list. Network monitoring adds the record of who talks to whom, which shows your zones and conduits work as drawn.
Because that record comes from live traffic, the evidence stays current. Events go out by syslog to your SIEM, so monitoring is part of daily operations rather than a yearly exercise.
Questions about OT network visibility.
Probes sent to your OT network. Access Gate only listens to traffic: NetFlow from your router or firewall, or a mirrored switch port. No scanning, no agents.
No. Access Gate works passively: it reads NetFlow from the router or firewall you already have, or traffic from a mirrored switch port. It never sends probes, installs agents, or generates traffic on your OT network. Deployment needs no downtime.
Yes. Access Gate works from network traffic rather than querying devices, so any machine that communicates shows up, including legacy PLCs, old HMIs, and proprietary equipment that can't run agents or answer SNMP. Each one is listed in the asset inventory.
Vulnerability scanners actively probe devices, which can crash sensitive OT equipment and adds noise to the network. Access Gate does the opposite: it watches traffic passively to show who talks to whom, without touching a single device.
NIST 800-171 for CMMC and IEC 62443 ask you to know your assets and control the flows between zones. The asset inventory holds the list; monitoring shows the flows and flags changes. The inventory exports on demand for auditors, and events reach your SIEM by syslog.
Yes. Access Gate sends its events by syslog to your SIEM, and the inventory can be exported on demand.
Active scanners send probes to devices to interrogate them, which can crash sensitive OT equipment and floods the control network with unexpected traffic. Access Gate does the opposite. It observes the NetFlow and PCAP the network already produces, and its WASM processing engine analyzes them on the appliance. It identifies every communicating device, including legacy and proprietary gear, without sending a single packet to a field device or installing anything.
Download the Access Gate Datasheet.
Get the complete product overview with technical capabilities, deployment model, compliance alignment, and customer references.
What's Inside
Product architecture, deployment model, key capabilities (proxy enforcement, micro-DMZs, identity-based access), compliance alignment, and real-world customer deployments.
See It in Action
Request a live demo to see how the Access Gate deploys on your network without rewiring or downtime.