Port 1012 — Reserved But Unused

What This Port Is

Port 1012 occupies the well-known port range (0–1023), a space reserved by IANA for system services and protocols defined by standards bodies¹. Within that range, it's supposed to mean something. According to some registries, it's labeled "DOLY," though what DOLY actually is or was has become difficult to trace².

Unlike port 22 (SSH) or port 443 (HTTPS), port 1012 has no widely deployed protocol. No RFC defines its use. No major software listens on it by default. It's registered but unassigned in the practical sense—a number that exists in the bureaucracy but not in actual use.

The Well-Known Ports Explained

The 0–1023 range exists because early networking needed reserved channels for critical services. When TCP/IP was young, someone decided: these first 1024 ports belong to the system, not to regular applications. Only root/administrator can bind to them. They're supposed to be stable, predictable, assigned by standards.

Port 1012 is part of that promise. But the promise was never fulfilled for this particular number.

Known Uses (Or Lack Thereof)

Search results mention "DOLY" as a service name², but:

• No RFC defines DOLY
• No major protocol implements it
• It doesn't appear in modern port registries with any active use
• No modern software appears to listen on it by default

Some systems have found other uses for port 1012 (proprietary applications sometimes bind to unassigned ports), but nothing canonical. Nothing that matters to the Internet as a whole.

How to Check If Something's Listening

If you want to see what's actually running on port 1012 on your machine:

On macOS/Linux:

sudo netstat -tlnp | grep 1012
# or
sudo lsof -i :1012

On Windows:

netstat -ano | find "1012"

Using a port scanner (check if it's open to network traffic):

nmap localhost -p 1012

Most of the time, you'll see nothing. Port 1012 will be listening to silence.

Why This Matters

Port 1012 represents a fundamental truth about numbering systems: they grow, but not evenly. IANA defined the well-known range as a way to prevent chaos. When you know port 22 is SSH and port 80 is HTTP, the Internet is more organized.

But that only works if:

1. Services get assigned to ports
2. Services actually use those ports
3. People know what they're for

Port 1012 fails on all three counts. It's assigned to nothing. It's used by almost nothing. And if something is using it, nobody remembers why.

It's a artifact of a system that tried to create perfect order, then discovered that order requires maintenance. Ports that nobody cares about get left behind. They're still there. They still work. But they drift into the margins.