Port 2647: SyncServer — A Name Without a Service

What Port 2647 Is

Port 2647 sits in the registered ports range (1024–49151). These are ports that organizations and developers can formally reserve with IANA for a specific service — the idea being that if you register a port, other software won't accidentally collide with you.

IANA's registry lists port 2647 as SyncServer, assigned for both TCP and UDP. The registrant contact on file is Shawn Casey at matrixone.com.¹

That's where the trail goes cold.

The Ghost Registration

No RFC documents the SyncServer protocol. No widely-used software ships with port 2647 as a default. Security databases don't flag it. Network monitoring tools don't recognize it. Whatever SyncServer was — a synchronization utility, an internal enterprise tool, something else entirely — it never made it into the public record in any meaningful way.

This is more common than you'd expect. The registered ports range contains hundreds of entries for services that were reserved during the late 1990s and early 2000s, assigned to companies that were acquired, pivoted, or simply closed. The port number remains reserved in the registry long after the software stops existing.

Port 2647 is one of those. It has a name. It has no body.

What This Means in Practice

If you see traffic on port 2647 on your network, it isn't the registered SyncServer service — it's something else. Common explanations:

• Custom application: Internal tools and proprietary software frequently pick high-numbered ports that appear unoccupied. A developer who checked the registry in 2010 might have found 2647 listed and assumed it was effectively free.
• Malware or unauthorized software: Unusual ports can be used to fly under the radar of firewall rules that only block well-known ports.
• Misconfiguration: A service bound to the wrong port.

The registered name offers no protection. IANA reservations carry no enforcement mechanism. Any process on your machine can bind to any port.

How to Check What's Using Port 2647

If you want to see whether anything is listening on this port right now:

macOS / Linux:

# Show what process is bound to port 2647
sudo lsof -i :2647

# Or with ss (Linux):
ss -tlnp sport = :2647

Windows:

netstat -ano | findstr :2647

The output will give you a process ID. Cross-reference it with Task Manager or ps aux to identify the owning application.

From outside the machine (checking if a remote host has something listening):

nc -zv hostname 2647
# or
nmap -p 2647 hostname

Why Unassigned Ports Matter

The port number space is finite: 65,535 total ports, shared across TCP and UDP. IANA's registry was designed to prevent collisions — if every application picked its port number at random, you'd have chaos. A web server accidentally sharing a port with a database would be a disaster.

But the registry is voluntary. There's no technical mechanism preventing any software from using any port. What the registry provides is coordination and convention. When ports like 2647 are registered but effectively abandoned, they become a kind of dead zone: technically claimed, practically available, and genuinely ambiguous when traffic appears on them.

The registered ports range — 1024 through 49151 — contains thousands of these. Ghost registrations from companies that no longer exist, protocols that never shipped, experiments that never left the lab. The addresses are reserved. Nobody's home.