Port 228: Unassigned — A Door With No Room Behind It

Port 228 is a well-known port with no known service. It sits in the range IANA reserves for system-level protocols (ports 0-1023), but it has never been assigned to anything.¹

The Well-Known Range

Ports 0 through 1023 are called "well-known ports" or "system ports." These are assigned by IANA through formal RFC processes or IESG approval.² This is where you find SSH (22), HTTP (80), HTTPS (443)—the fundamental protocols that make the Internet work.

Port 228 is in this range, which means at some point, someone thought it might matter. But three decades later, it remains empty.

What "Unassigned" Means

IANA marks port 228 as unassigned or reserved.³ This means:

• No official protocol uses it — There's no RFC defining a service for this port
• No common unofficial use — It doesn't show up in security research or network monitoring as carrying any consistent traffic
• Held for future use — IANA keeps it available in case a future protocol needs a well-known port number

Think of it as a reserved parking space that's been empty for thirty years.

Why This Matters

Unassigned ports tell you something about how the Internet evolved. When the well-known port range was created, engineers allocated 1,024 numbers. Some ports (like 22, 80, 443) became critical infrastructure. Others (like 228) were never needed.

The fact that port 228 remains unassigned after all this time suggests either:

• We overestimated how many well-known ports we'd need
• The protocols that needed standardization found other ports first
• Modern services increasingly use dynamic port allocation instead of fixed assignments

Checking What's Listening

Even though port 228 has no official assignment, something could be listening on it on your system. Here's how to check:

On Linux or macOS:

sudo lsof -i :228
# or
sudo netstat -an | grep :228

On Windows:

netstat -an | findstr :228

If you find something listening on port 228, it's either:

• Custom software configured to use this port
• Malware (uncommon, but possible)
• A misconfigured service

Because port 228 has no standard use, anything running on it is non-standard by definition.

Security Considerations

Unassigned ports are sometimes used by malware precisely because they're unexpected. The SANS Internet Storm Center tracks attack activity on all ports, including 228.⁴ While there's minimal documented malicious activity on this port, that doesn't mean it's safe to ignore.

If you see unexpected traffic on port 228:

• Investigate what's listening
• Check if it's legitimate software you installed
• Consider blocking the port at your firewall if nothing should be using it

The Empty Spaces

Port 228 is one of many unassigned ports in the well-known range. These empty spaces are a fossil record of Internet architecture—numbers allocated when we didn't know which protocols would matter, held in reserve in case we need them someday.

So far, we haven't needed port 228. Maybe we never will.

How to Check Port 228 Status

Want to see the current IANA assignment? Check the official registry:

• IANA Service Name and Transport Protocol Port Number Registry

Search for "228" and you'll find it listed as unassigned or reserved—a number waiting for a purpose that hasn't arrived yet.