Port 2239 belongs to the registered port range (1024–49151). IANA has not assigned it to any service.
What the Registered Range Means
Ports 1024–49151 are the middle tier of the port numbering system. Unlike the well-known ports below 1024 (HTTP, SSH, DNS), registered ports don't require root privileges to bind. Applications that need a consistent, recognizable port number — but aren't fundamental enough to claim a single-digit or two-digit port — register here.
IANA manages this range. An application can apply to reserve a number, pay nothing, and get a permanent listing in the registry. Tens of thousands of ports in this range are legitimately assigned. Thousands more, including 2239, are not.
The "Imagequery" Label
Some port reference databases list port 2239 with the service name "imagequery" and a description of "Image Query." This label appears to have entered circulation through a shared database that many port lookup sites pull from — not from an IANA assignment or any published RFC.
There is no protocol specification, no application with significant adoption, and no traceable registration for this name. It is stale data copying itself across the Internet, which is a common phenomenon in port reference sites. The IANA registry itself shows port 2239 as unassigned.1
If you see traffic on port 2239, it isn't because of "imagequery." It's because something on your network chose that number.
Security History
Some security scanners flag port 2239 as having been used by malware in the past. This is true of many unassigned ports — they're convenient precisely because nothing is officially listening there, making unexpected traffic harder to notice. An unassigned port drawing traffic is always worth investigating.
How to Check What's Listening on Port 2239
On Linux or macOS:
On Windows:
The process ID in the output can be matched to an application in Task Manager (Windows) or with ps aux | grep <PID> (Linux/macOS).
If nothing is listening, the port is idle. If something is listening that you don't recognize, that's the thing worth investigating — not the port number itself.
Why Unassigned Ports Matter
The port numbering system exists so that services can find each other reliably. Port 443 always means HTTPS. Port 22 always means SSH. The registry makes these agreements permanent.
Unassigned ports are the gaps between agreements. They're not broken — they're just unclaimed. Applications use them all the time for custom services, game servers, internal tools, and anything else that needs a network address but doesn't need to be universally recognizable.
Port 2239 is one of roughly 30,000 unassigned numbers in the registered range. Most of them will never be claimed. They wait, quiet, for traffic that may never come.
이 페이지가 도움이 되었나요?