Port 299: Unassigned — A Quiet Space in the Well-Known Range

Port 299 carries nothing. It has never been assigned a service by IANA, and in 2026, it likely never will be.

What Port 299 Is

Port 299 belongs to the well-known ports range (0-1023), also called system ports. These are the ports assigned by the Internet Assigned Numbers Authority through formal standards processes—IETF Review or IESG Approval.¹

According to IANA's official registry, ports 288-299 are unassigned.² That's a twelve-port gap sitting between port 287 (K-BLOCK) and port 300 (TLS Secure Login Host Protocol). Port 299 is one of many quiet spaces in the registry.

Why Unassigned Ports Exist

The well-known ports range isn't fully occupied. There are gaps throughout—dozens of unassigned port numbers that represent:

• Room for future protocols that were anticipated but never materialized
• Rejected proposals that didn't make it through the standards process
• Deliberate spacing to allow for logical grouping of related services

By 2026, the well-known ports range is effectively frozen. New services don't get assigned ports in the 0-1023 range anymore—they use registered ports (1024-49151) or dynamic ports (49152-65535) instead. The well-known range has become historical infrastructure, and unassigned ports like 299 represent the protocols that were never written.

What Might Be Using Port 299

Just because a port is unassigned doesn't mean nothing is listening on it. Organizations can use unassigned ports for:

• Internal services that don't need public registration
• Proprietary protocols that will never be standardized
• Testing and development environments
• Malware that picks arbitrary high-numbered ports to avoid detection (though 299 is low enough to require root/admin privileges on Unix systems)

If you find something listening on port 299, it's not official. Check what it is.

How to Check What's on Port 299

On Linux or macOS:

# See what's listening on port 299
sudo lsof -i :299

# Or using netstat
sudo netstat -tulpn | grep :299

# Or using ss (newer)
sudo ss -tulpn | grep :299

On Windows:

# See what's using port 299
netstat -ano | findstr :299

If you find a process listening on port 299 and don't recognize it, investigate. Unassigned ports in the well-known range are uncommon targets for legitimate services, which makes them worth examining when they appear.

The Well-Known Ports Range

Port 299 sits in a range that represents the Internet's earliest days. Ports 0-1023 were assigned when protocols were designed through RFCs and ratified by committees. Getting a well-known port meant your protocol mattered enough to be standardized.

That era is over. Modern services use higher port numbers, and the well-known range has become archaeological. The gaps—ports like 299—are the spaces between the things we built. They're part of the structure, even if they carry nothing.

Related Ports

• Port 287 (K-BLOCK) — The port before the gap
• Port 300 (TLS Secure Login Host Protocol) — The port after the gap
• Ports 288-298 — Also unassigned, part of the same twelve-port gap