Port 51
no service name · –
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | – |
| Service | no service name |
| Modified | 2013-05-24 |
Frequently asked questions
What is port 51 used for?
Port 51 is registered with the IANA for no service name (–). Description: Reserved.
Is port 51 a well-known port?
Yes. Port 51 is in the range 0–1023 (system or well-known ports). On Linux and macOS only privileged processes may bind to these ports.
How do I check whether port 51 is open?
Locally on Linux with ss -tulpn | grep ':51\b', on Windows with netstat -ano | findstr :51. To test a remote host use Test-NetConnection <host> -Port 51 in PowerShell or nc -zv <host> 51 on Linux/macOS.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| – | Reserved |