Port 3065: Slinterbase — A Name with No Story

What Port 3065 Is

Port 3065 is a registered port — officially assigned by the Internet Assigned Numbers Authority (IANA) to a service named slinterbase, for both TCP and UDP.

Beyond the name, the trail goes cold. There is no RFC, no product documentation, no open-source project, and no significant community discussion about what slinterbase is or was. The name appears in port databases, which cite each other, which cite the IANA registry. The registry itself offers only the name.¹

This is not unusual. The registered port range is full of reservations filed by companies and developers whose software never shipped widely, or quietly disappeared before the Internet had good memory.

The Registered Port Range

Port 3065 sits in the registered ports range: 1024 through 49151.

These ports are not as tightly controlled as the well-known ports (0-1023), which require IANA assignment for recognized protocols like HTTP, SSH, and DNS. Registered ports can be requested by anyone with a service to name. IANA reviews and approves them, but the bar is lower, and enforcement is nonexistent — the registry is a directory, not a lock.

What this means in practice: if you see traffic on port 3065 on your network, it's almost certainly not slinterbase. It's whatever application decided to use that port.

Security Notes

Some security databases flag port 3065 as having been associated with malicious traffic historically — scanners probing for open ports, or malware that used it as a command-and-control channel.² This is common for any quiet, unmonitored port in the registered range.

A flag like this means: someone, somewhere, once used this port for something bad. It does not mean the port is inherently dangerous. Any port can carry malware if the software on either end is malicious.

How to Check What's Listening on This Port

If you're curious what's using port 3065 on your own machine:

macOS / Linux:

lsof -i :3065

Windows:

netstat -ano | findstr :3065

If nothing is listening, the port is closed — which is expected. If something is, the output will show the process ID, and you can look it up to understand what application opened it.

Why Ghost Registrations Matter

The IANA registry serves a real purpose: coordination. When a protocol is widely deployed, registering its port prevents collisions — two services fighting over the same port causes chaos. But the registry also accumulates history. Services come and go; the registrations stay.

Ports like 3065 are artifacts of that accumulation. They represent a moment when someone had a plan, filed paperwork, and then — for reasons lost to time — moved on. The reservation remains, immortal and empty, keeping the name slinterbase alive in databases that will outlast anyone who remembers what it meant.