Port 3287: Unassigned — A Registered Port Claimed by No One

What Port 3287 Is

Port 3287 has no officially assigned service. IANA — the Internet Assigned Numbers Authority, the body that manages port registrations — lists it as unassigned in the registered port range.¹

It can be used by any application that chooses it. It just hasn't been formally claimed.

The Range It Belongs To

Port 3287 falls in the registered ports range: 1024–49151.

This is the largest of the three port ranges:

• Well-known ports (0–1023): Reserved for foundational protocols — HTTP, HTTPS, SSH, DNS, SMTP. Require root or administrator privileges to bind.
• Registered ports (1024–49151): Where named applications live — databases, game servers, enterprise software, developer tools. Anyone can apply to IANA to register a port here. No elevated privileges required to bind.
• Dynamic/ephemeral ports (49152–65535): Temporary ports assigned by the operating system for outgoing connections. Not registered, not named, constantly recycled.

Port 3287 sits in the middle of the registered range. Thousands of ports here carry well-known services. Thousands more are unassigned, like this one.

Any Known Unofficial Uses?

None that are widely documented. Some port scanners flag it alongside generic "potential trojan" warnings that apply to any port with observed traffic — these warnings reflect the behavior of scanning tools, not anything specific to port 3287. No known malware family has claimed it as a signature port.

If you see traffic on port 3287 on a machine you administer, it's almost certainly a local application or service that chose this port for its own reasons.

How to Check What's Listening

If you want to know what's using port 3287 on a specific machine:

On Linux or macOS:

sudo ss -tlnp | grep 3287
# or
sudo lsof -i :3287

On Windows:

netstat -ano | findstr :3287

The output will show the process ID (PID). Match that to a process name with Task Manager or tasklist.

Why Unassigned Ports Exist

The registered port space has 48,128 slots. The Internet has far fewer widely-used named services. Most registered ports are unassigned, not because the system is broken, but because registration is optional — applications can use any unoccupied port without going through IANA.

The registration process exists to prevent collisions: if your software needs a permanent, well-known home, you register. If you're flexible, you don't bother. Many widely-used applications pick ports without ever registering them.

Port 3287 is simply unclaimed territory in a very large range.