Command — Portqry

Checking TCP port 1433 (default instance) or dynamic ports for named instances. Example Output Querying target system called: sqlserver01.domain.com Attempting to resolve IP address to a name... IP address resolved to sqlserver01.domain.com

| Tool | Platform | Key Advantage | |------|----------|----------------| | Test-NetConnection | PowerShell (Windows) | Built-in, supports -Port parameter | | tnc alias | PowerShell | Shorthand for Test-NetConnection | | nmap | Cross-platform | Extensive scanning features | | telnet | Windows (disabled by default) | Simple, but no UDP support | | nc (netcat) | Cross-platform | Versatile, scriptable | # Test single TCP port Test-NetConnection -ComputerName server01 -Port 3389 Test with detailed output Test-NetConnection -ComputerName web01 -Port 443 -InformationLevel Detailed Where to Download Portqry can be downloaded from Microsoft Download Center as "PortQry Command Line Port Scanner" (portqry.exe) or as part of "PortQryUI" (GUI version). Final Thoughts While largely superseded by built-in PowerShell tools, Portqry remains valuable in legacy environments and for administrators who prefer its concise, script-friendly output format. Its ability to distinguish between "filtered" and "not listening" states makes it superior to basic connectivity testers in security-conscious environments. Note: The most recent version (PortQry 2.0) was released in 2006 and supports Windows 2000 through Windows Server 2008 R2, but continues to function on modern Windows versions. portqry command

Confirming whether firewall rules allow or block specific services without needing full access to the firewall management console. Checking TCP port 1433 (default instance) or dynamic

Verifying domain controller accessibility through ports 389 (LDAP), 88 (Kerberos), 135 (RPC), and 445 (SMB). Confirming whether firewall rules allow or block specific