Port 2624: Unassigned — An Empty Room in the Registered Range

What Range This Port Belongs To

Port 2624 falls in the registered port range: 1024–49151.

The Internet Assigned Numbers Authority (IANA) divides ports into three ranges, each with a different character:

• Well-known ports (0–1023): Reserved for foundational protocols. HTTP at 80, HTTPS at 443, SSH at 22. These require elevated privileges to bind on most systems and are jealously guarded.
• Registered ports (1024–49151): Where applications go to claim a stable home. A vendor submits a request to IANA, explains what their software does, and gets a number they can tell users to open. PostgreSQL lives at 5432. MySQL at 3306. Redis at 6379.
• Dynamic/ephemeral ports (49152–65535): Not claimed by anyone. Your operating system grabs from this pool for outbound connections — the temporary return address on every packet you send.

Port 2624 is in the middle tier. The neighborhood of claimed addresses. But this particular address has never been claimed.¹

No Known Unofficial Uses

Port databases list port 2624 as unassigned with no commonly observed unofficial uses. No major application defaults to it. No known malware is associated with it. No protocol has informally adopted it.

This is the honest state of most registered ports. IANA manages a registry of roughly 48,000 possible registered port numbers. Thousands are genuinely empty — never requested, never squatted, just unoccupied address space.

Why Unassigned Ports Matter

An unassigned port isn't neutral. Any process on your system can bind to port 2624 — no registration required, no permission needed. That's useful when you're running a development server and need a port that won't collide with anything known. It's also why security teams pay attention to unexpected traffic on unregistered ports.

If you see activity on port 2624 on your network, it's one of three things:

1. A legitimate application your organization runs that chose this port deliberately
2. A developer or internal tool that grabbed an available number
3. Something worth investigating

The absence of a known service assignment is the reason to look closer, not to assume safety.

How to Check What's Listening

On Linux or macOS:

# Show what process is bound to port 2624
sudo lsof -i :2624

# Or with ss (modern Linux)
sudo ss -tlnp sport = :2624

# Or with netstat
sudo netstat -tlnp | grep 2624

On Windows:

netstat -ano | findstr :2624

The PID in the output can be matched to a process name in Task Manager or with tasklist /fi "pid eq <PID>".

If nothing is listening, the port is idle. If something is listening and you don't recognize it, that's the question worth answering.