PortQry is a command-line utility developed by Microsoft that reports the port status of TCP and UDP ports on a local or remote computer. Unlike a simple Telnet test—which only tells you if a TCP connection succeeded—PortQry provides detailed information about the port’s state and can even query specific services to see how they respond. The Three States of a Port When you run PortQry, it returns one of three statuses: A process is listening on the target port. NOT LISTENING: No process is listening on the target port.
Useful for quickly verifying SMB and RPC ports. portqry
Portqry remains a valuable, lightweight tool for Windows-based network troubleshooting, particularly in environments where installing full network scanners is not feasible. Its ability to test both TCP and UDP ports, interpret service responses, and identify filtering devices makes it superior to built-in Windows tools for advanced diagnostics. While newer tools like Test-NetConnection in PowerShell offer convenience, Portqry’s deterministic output and low overhead keep it in the toolkit of experienced network professionals. PortQry is a command-line utility developed by Microsoft
: Specifically designed to enumerate local port usage, including port-to-process mapping (PID) and tracking changes in port status. NOT LISTENING: No process is listening on the target port