Port 10012 — Unassigned, Quietly in Use

What This Port Belongs To

Port 10012 falls in the registered port range (1024-49151), meaning it was technically eligible for IANA assignment but never claimed by a standards body or widely-used service. This makes it part of the Internet's middle ground—not system-critical like the well-known ports (0-1023), but not as wild as the ephemeral/dynamic range (49152-65535) either.

The Registered Port Range

When a port sits in 1024-49151, it means the IANA registry is ready to assign it to services upon application. In theory, any organization can apply for a port number and register a protocol. In practice, most applications either use widely-known ports (like 80, 443, 8080) or just claim an unused one quietly and move on. Port 10012 falls into that second category—officially unassigned, practically useful.

Known Informal Uses

Port 10012 shows up in a few places:

• YARP (Yet Another Robot Platform) — The robotics middleware system uses port 10012 for network communication between distributed robot components. YARP enables different parts of a robot to talk to each other over TCP. ¹
• Mudfish VPN — The VPN application has used port 10012 for UDP connections with FEC (Forward Error Correction) encoding in its connection protocols. ²
• Historical malware associations — Security databases flag port 10012 because backdoor trojans like "BackDoor-II.svr" have exploited it in the past. This doesn't mean the port is inherently dangerous, only that it has been abused. ³

None of these are official IANA registrations. They're just applications that picked this port because it was available.

How to Check What's Listening

If you need to see what's actually using port 10012 on your system, use these commands:

On Linux/macOS:

lsof -i :10012          # Simple list of what's on this port
ss -tulpn | grep 10012  # Modern, fast method
netstat -pan | grep 10012  # Traditional approach

On Windows:

netstat -ano | findstr :10012  # Show process ID using the port
tasklist /FI "PID eq [PID]"    # Then match to process name

These commands show the process name and PID, letting you identify exactly what claimed this port on your machine.

Why Unassigned Ports Matter

The 48,000+ registered ports represent the Internet's social contract: there are enough address spaces for everyone's service if they register. But the social contract only works if people use it. When applications skip registration and just occupy an open port, they're making a bet: "This port is obscure enough that I won't collide with anyone else's bet."

Port 10012 is that bet. It's not assigned because nobody important enough to secure IANA approval needed it. Yet it carries real traffic—robots coordinating movements, VPN packets finding their way through firewalls, maybe something else entirely running on your neighbor's network right now.

The unassigned ports are where the Internet's true flexibility lives. They're the difference between a rigid system and one that actually adapts.

See Also

• Port 80 — HTTP traffic, the web's backbone
• Port 443 — HTTPS, where encryption became standard
• Port 1024 — The boundary where the well-known ends and the registered begins
• Port 49152 — Where ephemeral ports start, the temporary allocations that exist only for the duration of a connection