Port 1810: Jerand License Manager — A Registered Ghost

What Port 1810 Is

Port 1810 sits in the registered ports range — the band from 1024 to 49151 where software vendors and protocol designers can formally claim a port number with IANA.¹

According to the IANA registry, port 1810 belongs to Jerand License Manager, service name jerand-lm, registered by someone named Robert Monat on both TCP and UDP.²

And that's essentially where the trail ends.

The Registered Port That Isn't

Registered doesn't mean active. The IANA registry is a first-come, first-served system — you submit a request, IANA records it, and the port is yours. There's no requirement that the software remain in use, remain documented, or even remain in existence.

Jerand License Manager appears to have been a software licensing system — one of many tools from the 1990s and early 2000s that managed seat-based licenses for commercial software. Products like FlexLM (now FlexNet) dominated this space. Dozens of smaller license managers competed for the same market. Most of them are gone.

No website for Jerand survives. No support documentation. No forum posts. No corporate record. The port is registered; the software is a ghost.

What This Means in Practice

If you see traffic on port 1810 on your network, it's almost certainly not Jerand License Manager. More likely explanations:

• Custom application: An internal or proprietary tool that chose this port because it appeared unregistered (it nearly is)
• Dynamic assignment: Your operating system temporarily assigned this port to outgoing traffic as an ephemeral source port (though 1810 is technically below the ephemeral range)
• Malware or scanning: Unusual port activity is worth investigating

How to Check What's Using Port 1810

On any machine where you see activity on this port:

Linux / macOS

# Show what process is listening on port 1810
sudo ss -tlnp | grep 1810

# Or with lsof
sudo lsof -i :1810

Windows

# Show listening connections with process IDs
netstat -ano | findstr :1810

# Find the process name from the PID
Get-Process -Id <PID>

Why This Port Matters (as a Lesson)

The registered port range exists so software can reliably claim a port number without colliding with others. It works reasonably well for active, maintained software. But the IANA registry has no mechanism for reclaiming abandoned registrations.

The result: hundreds of ports in the 1024–49151 range are registered to software that no longer exists. They're not available for re-registration, but they're also not doing anything. The space is claimed but empty.

Port 1810 is one of the cleaner examples of this phenomenon — registered to a real contact name, a real service name, and what was probably real software. But the software is gone, and the port sits in a kind of bureaucratic limbo: officially taken, functionally free.