Port 3080: stm-pproc — A Registered Port Nobody Remembers

What Range This Port Belongs To

Port 3080 sits in the registered port range (1024–49151), also called user ports. These are ports that organizations and developers can formally reserve with IANA — the Internet Assigned Numbers Authority — so their software has a predictable, recognized home.

Registered ports are not locked down the way well-known ports (0–1023) are. You don't need root or administrator privileges to bind to them. Any process on your machine can open port 3080. The IANA registration is more like a claim flag than a lock.

The Official Assignment: stm-pproc

IANA has assigned port 3080 (both TCP and UDP) to a service called stm-pproc (the older form, stm_pproc, is considered historic — underscores cause problems with service discovery systems, so IANA created the hyphenated replacement). ¹

The registration contact points to server.stmi.com, a domain that leads nowhere traceable today. The service name suggests "STM pre-processing" or something similar, but what it actually did, which software used it, or whether any production system ever ran on port 3080 under this name — none of that is documented anywhere findable.

It's a ghost registration. The name exists in the IANA table. The service behind it has vanished.

What Actually Uses Port 3080

Because the official assignment is effectively dormant, port 3080 turns up in the wild for unrelated reasons:

Alternative HTTP / proxy ports. Developers and tools frequently need a non-standard HTTP port — something other than 80, 8080, or 8000. Port 3080 appears in configuration files for web proxies, local development servers, and containerized applications that need to avoid conflicts. It has no particular convention behind it; it's just available.

Gaming. Rainbow Six Vegas used a UDP port range spanning 3074–3174, which includes 3080. ² This is common with multiplayer games — they grab a range rather than a single port.

Malware. Port 3080 has been associated with Trojan-Dropper.Win32.Delf.p, which exploited a remote buffer overflow vulnerability on this port. ² This is worth knowing if you see unexpected activity here — a process listening on 3080 that you don't recognize deserves investigation.

How to Check What's Listening on Port 3080

If you see traffic on port 3080 or want to know what's using it on your system:

On Linux/macOS:

# Show what process is listening on port 3080
ss -tlnp | grep 3080

# Or with lsof
lsof -i :3080

On Windows:

netstat -ano | findstr :3080

The output will give you the process ID. Cross-reference that with your process list (ps aux on Linux/macOS, Task Manager on Windows) to identify what's running.

Why Unassigned Ports Matter

The registered port range has 48,128 slots. Most of them are either lightly used, claimed by forgotten services, or informally squatted by software that never bothered to register.

This creates a practical reality: when you configure software to run on a non-standard port, you're making a choice in a space with no real traffic control. Port 3080 won't conflict with anything critical. But it also won't protect you from something else deciding to use the same number.

The IANA registry is a good-faith system. It works when everyone registers. When registrations expire or services disappear, the slots become de facto open land — and port 3080 is one of them.