Port 60667 — The Unassigned Number in Apple's Filesystem

What This Port Range Means

Port 60667 falls within the dynamic and ephemeral port range: 49152 to 65535. These are ports that IANA (the Internet Assigned Numbers Authority) deliberately left unassigned. They belong to nobody. They're the free real estate of the port system. ¹

When a service needs a port and doesn't want to wait for official assignment—or when it's temporary and short-lived—it grabs a number from this range and listens. The operating system often does this automatically for outbound connections, assigning you a random ephemeral port for the return traffic. Your client connections to port 443, to port 80, to anything else—they come back on one of these unassigned numbers.

Known Uses on Port 60667

Apple's Xsan (Storage Area Network filesystem) is documented as using port 60667 for filesystem access operations. ² If you see this port listening on a Mac with Xsan deployed, that's what it is.

But that's just one application in an ocean of possibilities. Because this range is unassigned, any software can use any port in it without asking permission. Your backup tool. Your P2P sync. Your custom application. Your developer testing their new service. They could all pick 60667.

How to Check What's Using This Port

To see what's listening on port 60667:

On macOS:

lsof -i :60667
netstat -an | grep 60667

On Linux:

netstat -tlnp | grep 60667
ss -tlnp | grep 60667

On Windows (PowerShell):

netstat -ano | findstr :60667

The output will tell you the process ID. If it's something you recognize (Xsan, your IDE, a running service), you know what it is. If it's something you don't recognize, you have a legitimate mystery.

Why Unassigned Ports Matter

The dynamic range is democracy in the port system. It's why your application can start listening without waiting for bureaucratic approval. It's why your machine can assign you a return port for every outbound connection without conflict. It's also why you can have collisions—why port 60667 might mean something different on two different machines.

This is by design. The Internet understood early on that you couldn't possibly assign every port to every service forever. So they carved out a huge range and said: "This is yours. Use it however you need. Don't tell us."

Port 60667 is just a number in that range. It could be nothing. It could be something important to your system. The fact that it's unassigned is the whole point.