Port 10323: Unassigned — A Quiet Stretch of Open Road

What Port 10323 Is

Port 10323 is an officially unassigned port number in the IANA (Internet Assigned Numbers Authority) Service Name and Transport Protocol Port Number Registry. It sits in the registered port range (1024-49151), which means it's set aside for applications that request formal registration.

Nobody owns it. The IANA doesn't assign it to anything. So what happens?

The Port Range System

The Internet divides ports into three ranges:

• Well-known ports (0-1023): Reserved by IANA for system services. SSH gets 22. HTTP gets 80. DNS gets 53. These are sacred.
• Registered ports (1024-49151): Available for application developers to request and register with IANA. The waiting room for protocols that want to be official.
• Dynamic/private ports (49152-65535): Free for anyone. No registration needed. Temporary connections, ephemeral services, whatever you want.

Port 10323 is in that middle zone. It's registered (meaning it's not in the dynamic range where anything goes), but it's unassigned (meaning nobody claimed it).

What Actually Uses Port 10323

In practice, port 10323 has been observed carrying traffic from video game applications:

• FIFA series (multiple versions, Steam and PlayStation 3 platforms)
• Madden NFL (versions 19-21, including Steam versions)
• Mass Effect: Andromeda (PC, PlayStation 4, Xbox One)
• Dungeon Defenders II and Dungeon Defenders: Awakened (Steam)
• Camfrog (social video platform)

These are not official assignments. The game studios didn't register with IANA. They needed a port for their peer-to-peer networking or matchmaking servers, found this one was empty, and used it. The port carried their traffic for years without any formal claim.

Why This Matters

The unassigned ports reveal something about how the Internet actually works versus how it's supposed to work. The IANA registration system exists to prevent conflicts—to ensure that if you're running SSH, port 22 means SSH everywhere. But between the sacred well-known ports and the lawless dynamic range sits this middle ground where applications can just... take what they need.

Port 10323 was never registered by FIFA or Madden. There's no RFC. There's no standardization. It's borrowing.

How to Check What's Listening

To see if something is actually listening on port 10323 on your system:

On Linux/macOS:

# Using netstat (older, still works)
netstat -tulpn | grep 10323

# Using ss (newer, recommended)
ss -tulpn | grep 10323

# Using lsof (shows process names)
lsof -i :10323

On Windows:

netstat -ano | findstr :10323

If nothing appears, the port is silent on your machine. If something does appear, you'll see the process ID and program name—that's what claimed this unassigned piece of the Internet.