Port 979: Unassigned — A ghost in Apple's old RPC neighborhood

Port 979 belongs to the well-known ports range (0-1023), which is managed by the Internet Assigned Numbers Authority (IANA). These are the ports reserved for the most fundamental Internet services—HTTP, HTTPS, SSH, DNS. But port 979 was never officially assigned a service.¹

The NetInfo Connection

Port 979 was historically associated with Apple's NetInfo, a directory service used in early versions of Mac OS X for storing user accounts, network configuration, and system information.² NetInfo used RPC (Remote Procedure Call) services that operated across the TCP/UDP port range 600-1023.³

But NetInfo is gone. Apple began replacing it with Open Directory in Mac OS X Server 10.2 (2002) and completely removed it in Mac OS X 10.5 Leopard (2007).⁴ Modern macOS systems don't use NetInfo. Port 979, like the service it once carried, exists only as a historical artifact.

What "Unassigned" Means

When a port in the well-known range is unassigned, it means:

• No official service — IANA hasn't designated a protocol or application for this port
• No RFC definition — There's no standards document defining what should run here
• Potential for unofficial use — Applications can use it, but there's no coordination to prevent conflicts

Port 979 sits in valuable real estate—the well-known range is finite and carefully managed—but it remains unclaimed.

Why Unassigned Ports Matter

The existence of unassigned ports in the well-known range tells a story about the Internet's evolution. Some ports were never needed. Some, like 979, were used by proprietary services that didn't require IANA assignment. Some are held in reserve for future standards.

Unassigned ports are also safer. They're less likely to be targeted by automated attacks because there's no known service to exploit. A port scan hitting 979 finds nothing—no banner, no handshake, no vulnerability.

Checking What's Listening

Even though port 979 is unassigned, something could be listening on it. To check on your system:

On macOS or Linux:

sudo lsof -i :979

On Windows:

netstat -ano | findstr :979

Using nmap:

nmap -p 979 localhost

If nothing returns, the port is closed. If you see a process ID, something is using it—and you should probably find out what.

The Silence of Empty Ports

Port 979 is a reminder that not every number between 0 and 1023 needs to carry something. The well-known range isn't fully occupied. There are gaps, quiet spaces, ports that were reserved and never used.

This port was once part of Apple's directory services infrastructure. Now it's just a number in a registry, waiting. Whether it will ever be officially assigned is unknown. For now, it remains what it's always been: unassigned, unused, and unremarkable.