Port 2435: OptiLogic — A Registered Ghost

What This Port Is

Port 2435 is a registered port — sitting in the 1024–49151 range that IANA administers for named services. According to the official registry, it belongs to something called "optilogic" (service name) / "OptiLogic" (description), registered under the name Clark Williams.¹

That's where the trail ends.

There is no RFC. There is no surviving documentation of what the OptiLogic protocol did, how it worked, or what problem it solved. The company called Optilogic that exists today — a cloud-native supply chain optimization platform — almost certainly has nothing to do with this registration.² It predates them.

The Registered Ports Range

Ports 1024–49151 are called registered ports. The idea was straightforward: organizations that build network services can register a port number with IANA, creating a stable, known address for their software to communicate on. Unlike the well-known ports (0–1023), these don't require root/administrator privileges to open, and they span a wide range of enterprise, industrial, and application-layer services.

The registration process worked better in theory than in practice. Services were registered, companies folded, products were discontinued — and the registrations remained. IANA's list is littered with names that point to nothing: software that no longer ships, protocols that were never documented publicly, and contact names with no reachable humans behind them.

Port 2435 is one of those.

Security Notes

Some port databases flag 2435 as historically associated with malware activity.³ This is a common fate for quiet, unmonitored ports — if legitimate software isn't actively using a port, it becomes attractive for programs that want to go unnoticed. An open port 2435 on a system with no known OptiLogic software warrants investigation.

How to Check What's Listening

If you see port 2435 active on a system and want to know what's using it:

Linux / macOS:

sudo lsof -i :2435
sudo ss -tlnp | grep 2435

Windows:

netstat -aon | findstr :2435

Then take the process ID from the output and look it up:

# Linux/macOS
ps aux | grep <PID>

# Windows (Task Manager, or:)
tasklist | findstr <PID>

If something is listening on this port and you don't recognize it, that's worth investigating.

Why This Matters

The registered ports range was built on an assumption: that registrations would remain meaningful. They often don't. Services die, companies are acquired, software is abandoned — but port numbers are forever. The result is thousands of entries in IANA's registry that are, in practice, unassigned.

Port 2435 is honest about what it is: a name on a door, with no one on the other side.