Sometime we need an easy to use alternative for open port checker under windows, in this article we will talk about the following options to accomplish it, telnet, putty and PowerShell.
The telnet command line tool:
With modern windows distribution, the telnet command is no longer a build in tool, we need to manually install it. Once we do it we can use it as an internal command.
Open command line and type in telnet and press enter.
If it does NOT give you and error telnet is install, to exit from it type quit and press enter.
Next step is to set it a target host and port to check:
c:> telnet openport.net 443
In case of an error like this:
‘telnet’ is not recognized as an internal or external command,
operable program or batch file.
Please follow this:
- Open “Control Panel”.
- Open “Programs and Features”.
- Select the “Turn Windows features on or off ” option.
- Check the “Telnet Client” box.
- Click “OK”.
Wait for the installation progress on the Windows Feature to finish.
If you get a back screen or some text on a black screen means the remote port is open on the target server.
To exit from the telnet black screen type quit and press enter.
Cool, we use telnet as an open port checker tool!
Putty free tool:
PuTTY is a free implementation of SSH and Telnet for Windows and Unix platforms, along with an
xterm terminal emulator. It is written and maintained primarily by Simon Tatham.
Using putty you can make a remote connection using one of it supported protocols like SSH and Telnet, I am using it to remote connect to a Linux box using the SSH protocol.
The only disadvantage, in related to our conversation is that you need to download it from the internet – this is not a build in tool.
You can download it form this link: PuTTY
Once downloaded open it and you will see the following screen:
How to use:
- Select telnet.
- Set Host and Port
- Press: Open
If you see the following message – the remote port is close:
Cool, we use putty as an open port checker tool!
Putty is much more the a port checker tool, this is a full remote terminal tool that you can use, especially if you need to connect to Linux base box.
Using PowerShell to check for remote or local open ports. If you have PowerShell installed on your windows box you can use it to check for open port.
You just need to write a small script and to run it.
Start the Windows PowerShell ISE
Put the following code into it:
echo ((new-object Net.Sockets.TcpClient).Connect($targetServer,$targetPort)) "$targetPort is
open on $targetServer.";
You need to set the target server and the target port and to run the script.
A message like 443 is open on openport.net with your server and port indicate that the port is open.
A time out error means the port is close:
By the Way, You can use this also to check if a local port is open or close, how?
- Set the target server as ‘localhost’
- Set the target port as the port to check.
- Run the script.
Cool, we use PowerShell scripting as an open port checker tool!
Free open port checker under windows:
Using the above method you can easily craft an open port checker on your windows operation system.
The cools thing is that it is easy to use, free and available in every Windows box.
Hope you like it, and if it helps you please share it with your friends or coworkers.
As a final note, we have here a free Windows Open Port Check Tool that you can download and use.
Please check other article in our free online open port check tool website.