Port 2831: silkp3 — Registered, Unknown, Forgotten

What This Port Is

Port 2831 sits in the registered port range — the stretch from 1024 to 49151 that IANA manages on behalf of software vendors, protocol designers, and anyone willing to fill out a registration form. Unlike the well-known ports below 1024 (where HTTP, SSH, and DNS live), registered ports aren't reserved by ancient decree. They were requested.

Someone requested port 2831. IANA assigned it to a service called silkp3. And then, apparently, nothing else happened.

The IANA registry entry for port 2831 reads:

The description field contains the service name. The assignee field is empty. There is no RFC, no linked documentation, no contact information. Whatever "silkp3" was or was supposed to be, the trail ends at the registration.¹

What "silkp3" Might Have Been

The name suggests a pattern: a product called "Silk," protocol version 3. This is speculation — there is no public documentation confirming it. There are unrelated things named Silk (an audio codec from Skype, a network traffic analysis tool from CERT), but neither connects to this port number in any traceable way.

This happens. A company registers a port for internal software, the software never ships publicly (or ships under a different port), the company dissolves or changes direction, and the registration stays in IANA's registry indefinitely. Port numbers don't expire.

What You Should Do If You See It

If you see traffic on port 2831 in your network logs, the honest answer is: something chose it, and you should find out what.

On Linux/macOS:

# See what process is listening on port 2831
sudo ss -tlnp | grep 2831
sudo lsof -i :2831

On Windows:

netstat -ano | findstr :2831

Take the PID from the output and look it up. That process is your answer.

Why These Ghost Registrations Exist

IANA's port registry is not a curated museum — it's a historical record. Ports get registered, projects get abandoned, companies disappear, and the registrations stay. Of the roughly 48,000 ports in the registered range, a significant portion have registrations with no reachable assignees, no documentation, and no known implementations.

This creates a kind of port archaeology problem. When you see an unrecognized port number in your network traffic, you can't always trust the registry to tell you what it is. The registration might be stale. The software might have moved to a different port. Or it might be something entirely undocumented that claimed the number opportunistically.

Port 2831 is technically taken. In practice, it's empty.