If you have ever worked with networks in Linux environments, you certainly know and love netcat (or nc), the famous “Swiss Army knife” for network diagnostics.
But when migrating to Windows, many system administrators and security analysts wonder: is there a native and equally powerful equivalent?
The answer is a big yes! In modern Windows, this functionality is brilliantly covered by a dynamic duo of PowerShell commands: Test-NetConnection and Test-Connection.
In this tutorial, we will explore the main functions of this Swiss Army knife, showing how you can perform the most common network diagnostic tasks quickly and efficiently, directly from your terminal.
Checking for Open TCP Ports (The Classic Netcat Function)
The most common task for netcat is to check if a specific TCP port is open on a remote host.
This is essential for diagnosing firewall issues or for confirming if a service (like a web server, an SQL database, or an RDP connection) is responding.
With Test-NetConnection, the syntax is clean and straightforward.
Example: Check if the HTTPS port (443) on localhost is accessible.
Test-NetConnection localhost -Port 443
What to expect: If the connection is successful, the output will show TcpTestSucceeded: True. If it fails, the value will be False, indicating a block or that the service is not active.
Testing Basic Connectivity (The Modern “Ping”)
The good old ping is still useful, but Test-Connection is its modern successor. It not only checks if a host is online but also provides a structured output in object format, which is perfect for use in automation scripts.
Example: Test connectivity with localhost.
Test-Connection localhost
Mapping the Connection Route (The Native “Traceroute”)
Need to identify network bottlenecks or understand which “hops” (routers) your connection passes through to reach the destination? Just add the -Traceroute parameter to Test-NetConnection.
Test-NetConnection localhost -TraceRoute
Bonus: And For Testing UDP Ports? Use PortQry
The commands we’ve seen are focused on TCP and ICMP. Testing UDP ports is a different challenge, as the UDP protocol does not establish a connection or confirm the receipt of packets.
For this task, the best tool, recommended by Microsoft itself, is PortQry.
It has a version with a graphical interface (PortQryUI) that greatly facilitates testing UDP ports, commonly used in services like DNS (port 53), NTP, or in many online games.
Furthermore, it sends a formatted packet to the service and analyzes the response to determine if the port is “listening”.
Important Notice: Ethics and Legality
It is crucial to reinforce that any network test, especially of ports, performed on third-party devices or networks must have the express authorization of the owner. Performing unauthorized scans can be interpreted as malicious activity and violate laws and usage policies. Use these tools responsibly and ethically.
Conclusion
Although missing netcat is understandable, PowerShell on Windows offers a native, powerful, and modern arsenal with Test-NetConnection and Test-Connection.
Mastering this dynamic duo is an essential step for any IT professional, SysAdmin, or security specialist working with the Microsoft ecosystem.
See more:
How to install and configure NGINX on Linux
Tutorial: How to Install OPNsense on VirtualBox
Congestion Control in Networks: Optimizing Efficiency and Bandwidth Allocation
Packet Tracer network with one router
How to Use Snap Behind a Proxy on Linux (Step-by-Step Guide)
Juliana Mascarenhas
Data Scientist and Master in Computer Modeling by LNCC.
Computer Engineer
