Port 3213: NEON 24X7 Mission Control — A Ghost in the Registry

What Port 3213 Is

Port 3213 sits in the registered port range (1024–49151), the middle tier of the port number space where IANA formally assigns ports to specific applications by request.

The IANA registry lists port 3213 as assigned to a service named neon24x7 — short for NEON 24X7 Mission Control, an enterprise monitoring product built by NEON Systems, Inc. of Austin, Texas.¹

NEON Systems was founded in 1995 to serve mainframe environments. Their 24X7 Mission Control software was designed to monitor and manage business applications across an enterprise via the Internet. The trademark was filed in December 2000.²

The company and the software are effectively gone. What remains is the port number, carrying a name attached to nothing running.

What the Registered Range Means

The registered port range (1024–49151) works on an honor system. IANA records an assignment when a company or project requests one. But IANA doesn't verify that the software still exists, that the company still operates, or that anything is actually listening on the port.

The result: the registered range is full of ghosts. Products discontinued. Companies acquired or dissolved. Startups that never shipped. Port 3213 is one of several hundred ports in this category — officially named, practically vacant.

This matters because:

• Port scanners will flag it. If something appears on port 3213, security tools may not recognize it against a known service profile
• Malware uses obscure ports. Unmonitored registered ports are convenient for command-and-control traffic that blends into the noise
• Applications squat on them. Development tools, internal services, and personal projects often grab quiet registered ports without filing with IANA

How to Check What's Listening

If port 3213 shows activity on a system you're investigating:

# On Linux/macOS — show what process has port 3213 open
sudo ss -tlnp sport = :3213
# or
sudo lsof -i :3213

# On Windows
netstat -ano | findstr :3213
# Then look up the PID:
tasklist | findstr <PID>

If something is listening on 3213 and you didn't put it there, that's worth investigating. The port has no legitimate active software tied to it today.