Windows Commands / IT Support Guides
Map Windows listening ports with netstat
A local service may be running while listening on the wrong interface or port. Inspect sockets before changing firewall rules.
Environment and inputs: Windows 11 · Command Prompt unless PowerShell is specified
Try the diagnostic command
Use the stated shell and platform. Replace sample domains, addresses, services and paths with values from the system you are authorized to support.
netstat -anoHow to read the result
LISTENING entries identify TCP server sockets. The last column contains a process ID. An address of 127.0.0.1 limits access to the local host, while a wildcard binding may accept traffic on several interfaces.
What to do next
Match the PID to Task Manager or tasklist, then compare the binding with the service configuration. Test the expected port from the client that actually fails.
Before you make a change
An established connection does not prove the application request succeeded. Avoid publishing full connection lists because they can reveal internal endpoints.