Factories & OT
See what's reachable on your factory floor before a contractor does
AdminKit's free tools let factories check remote-access exposure today, including port forwards like VNC, RDP, or Modbus TCP that a contractor opened for a single maintenance job and nobody ever closed afterward, plus a live Modbus TCP exposure check and, from the Netbase team, a quoted redesign to outbound-only, identity-based remote access.
Updated
At a glance
Part of the Machine protocols cluster — more tools, guides and terms on machine protocols.
The problem
Factory floors run a mix of machines, sensors, and controllers that were often installed years apart by different vendors, with little central tracking of what’s connected to what. Some of this equipment “calls home” to a vendor’s server for telemetry or firmware updates as part of normal operation, a configuration decision that’s easy to lose track of once the installer has left.
A more pressing issue is remote access for contractors and maintenance staff. It’s common for a technician to need temporary access to a machine’s control system, and for that access to get set up quickly, often as a port forward to a protocol like VNC, RDP, or Modbus TCP, aimed at getting the job done that day. The trouble is that this kind of access routinely stays open long after the maintenance job is finished, because closing it isn’t anyone’s specific responsibility.
Industrial protocols like Modbus were generally designed for isolated networks and don’t include built-in authentication, which is fine as long as the network stays isolated. Once a path from the internet reaches that network, there’s often nothing checking who’s allowed to send commands.
Talk to an expert
Huy Nguyen (David), Founder & CEO, Netbase JSC
Ask how AdminKit fits factories & ot — setup, timeline, or pricing.
What can a factory check for free?
- Check which commonly-exposed ports are open — useful for spotting a port-forwarded VNC, RDP, or Modbus path (port 502) left open after a maintenance job.
- Check your public IP and whether it’s shared via CGNAT — helpful context before investigating exposure further.
- Check whether a Modbus TCP device answers on your IP — queries the Modbus protocol directly to confirm a device actually responds, not just that the port is open, reading back only its identity.
If port-check finds port 502 open, is Modbus TCP (port 502) exposed covers the immediate fix, and the Modbus TCP 502 remediation playbook goes further, into the network-architecture work that keeps it closed.
How does Netbase fix contractor remote access?
OT remote access from AdminKit is a Netbase engagement, not a box you install yourself. Netbase replaces raw port forwards with outbound-only, identity-based access for contractors, with session recording and scheduled maintenance windows so access isn’t left open indefinitely. It is scoped as the factory remote-access redesign on services and quoted per site, since every floor is different. Talk to our team to start with a review of your current remote-access paths.
The free tools above only check what’s reachable from outside your factory’s network; they don’t see inside it or touch production systems unless you’re running the check against your own equipment with consent. Mapping out current remote-access paths and checking which ports are still open from old maintenance jobs is the right first step before any redesign.
Modbus isn’t the only building-automation protocol left exposed by a forgotten port forward — see BACnet/IP exposure in building automation for the same pattern on HVAC and access control systems.
This page is general guidance, not a security audit of your specific network — see our disclaimer for what AdminKit's guidance does and does not commit to.
Frequently asked questions
Is it safe to run the Modbus check tool on our equipment?
Yes, within its limits. AdminKit's modbus-check tool runs only against the public IP you are connecting from, or an asset whose ownership you've verified, never a network you don't control. It reads back only the device's identity (vendor and product, via Modbus function 43), never a coil or register, so it does not change anything on the device.
Can AdminKit see data moving on our factory floor network?
No. From outside, AdminKit only sees what's reachable at your public IP, the same as any other visitor would see. It would only see more if you specifically connected an agent or a remote-access setup that Netbase builds with you.
What's the problem with giving contractors VNC or RDP access?
The access itself isn't the problem; the issue is that it's often set up quickly through a port forward for a single maintenance job and then left open indefinitely. Nobody ends up tracking who has access or when it was last used.
How do we replace port forwards for contractors?
Netbase redesigns factory remote access as a custom engagement: outbound-only connections with no inbound port, per-contractor identity, recorded sessions and maintenance windows that close access when the job ends. Talk to our team at /contact/ or see the factory remote-access redesign on /services/.
Do machines really send data to vendors without IT knowing?
It happens when equipment is set up to phone home for telemetry or updates as part of its normal operation, and that configuration isn't documented or reviewed afterward. It's a configuration gap more than anything malicious, but it's still worth knowing about.
More in the Machine protocols cluster
Want AdminKit set up for you?
Tell us about your setup — our team will scope AdminKit for it and, if you need it, add hands-on expert help from Netbase.
How AdminKit works with you
- Delivered remotely — Netbase JSC, the company behind AdminKit, has worked with clients in 80 countries.
- Contracts and invoices are issued by Netbase JSC; payment goes to the company by bank transfer to Netbase JSC's company account or PayPal Business.
- Talk to the CEO, Huy Nguyen (David), directly on WhatsApp or by email at [email protected].