Port 123 — NTP

Network Time Protocol. Synchronizes clocks between computers. Critical for authentication and logging.

Is Port 123 Open on Your Server?

Test it now with our Port Scanner

Port 123 Details

Port123
ServiceNTP
ProtocolTCP / UDP
EncryptedVaries
Common UseNetwork Time Protocol

How to Check Port 123

Online: Use our Port Scanner — enter your IP and port 123.

Command line:

nc -zv your-server-ip 123 (Mac/Linux)

Test-NetConnection -ComputerName your-server-ip -Port 123 (PowerShell)

Check locally:

ss -tlnp | grep :123 (Linux)   netstat -an | findstr :123 (Windows)

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