Port 2626: Unassigned — An empty door in the registered range

Port 2626 has no assigned service. The Internet Assigned Numbers Authority (IANA) lists it as unassigned in the registered port range.¹

What Range This Port Belongs To

Port 2626 sits in the registered ports range: 1024 through 49151.²

This range exists for a specific purpose. Well-known ports (0–1023) are reserved for foundational protocols — HTTP, SSH, DNS, SMTP. They require elevated privileges to bind on most operating systems. The registered range is the next tier: applications and services can apply to IANA to claim a port number here, creating a stable, published address that other software can find them at.

Port 2626 hasn't been claimed. It's reserved space in a finite system — 65,535 ports total — with no occupant.

Any Known Unofficial Uses

No widely-used legitimate application claims port 2626 as a default. Security databases note that, like many obscure ports, it has appeared in historical malware activity — trojans and remote access tools occasionally use unassigned ports specifically because no legitimate traffic is expected there, making anomalies harder to spot.³

That association isn't specific to 2626. It's the nature of unassigned ports: they're quiet neighborhoods, which makes them attractive to software that wants to go unnoticed.

How to Check What's Listening on This Port

If you need to know whether something is using port 2626 on a machine:

On Linux/macOS:

# Show what process is listening on port 2626
ss -tlnp | grep 2626

# Or with lsof
lsof -i :2626

On Windows:

netstat -ano | findstr :2626

The output will show the process ID. Cross-reference that with Task Manager or ps aux to identify what's running.

Why Unassigned Ports Matter

The port system only works because most ports are quiet. When you see traffic on port 443, you know HTTPS. When you see port 22, you expect SSH. This predictability is how firewalls make fast decisions, how monitoring systems flag anomalies, and how network engineers debug problems.

Unassigned ports are part of that system. They define the silence against which unusual activity becomes visible. Port 2626 being empty isn't a gap — it's a baseline. If you find something listening on it, the absence of an expected service is itself the signal.