Port 2646: AND License Manager — A Registered Port with a Quiet History

What This Port Is

Port 2646 sits in the registered port range (1024–49151). IANA has assigned it to AND License Manager, a licensing management service registered by Dick van der Sijs at the Dutch company AND (and.nl).¹

Both TCP and UDP are officially registered at this port.

The Registered Port Range

Registered ports are different from the well-known ports below 1024 in one important way: you don't need root or administrator privileges to open them. Any application can listen on port 2646. The registration with IANA is a convention — a way of saying "this is ours, please don't use it for something else" — but it carries no enforcement.

The range contains tens of thousands of registrations. Many were made for software products that no longer exist, or that served such narrow audiences they never became part of the common vocabulary of the Internet. Port 2646 appears to be one of these: a legitimate registration for a real product that never became widely deployed.

AND License Manager

AND was a Dutch software and mapping company. License managers are the kind of software that runs quietly in the background of enterprise environments — enforcing seat limits, tracking concurrent users, making sure software licenses are respected. In the era before cloud licensing, nearly every serious enterprise software package shipped with something like this.

AND License Manager appears to have served that function for AND's own software products. If you encounter this port open on a system, it almost certainly belongs to a legacy AND software installation, not to anything else.²

What to Do If You See This Port Open

If port 2646 is open on a system and you don't know why:

On Linux/macOS:

sudo ss -tlnp | grep 2646
# or
sudo lsof -i :2646

On Windows:

netstat -ano | findstr :2646
# Then look up the PID:
tasklist | findstr <PID>

If you find a process you don't recognize and have no AND software installed, treat it as you would any unexplained open port: investigate before dismissing.

Why Unassigned-in-Practice Ports Matter

The port registry is a map, not a territory. IANA records what was registered, not what is actually running. Port 2646 is "assigned" in the registry but effectively dormant in practice — which means it's also available for anything that wants to use it informally.

This is normal. The registered port range was never meant to be a strict reservation system. It's a coordination mechanism, and coordination only works when enough people pay attention to it.