We all know we can use Ping to test IP accessibilty some windows platform. However, sometimes we not only want to test if we can access some ip address or domain, we would like also want to test if we could access some specified port. For example, if you would like to access https://www.some.site, but you cannot open it in browser, it could be because you have been blocked by firewall for your local ip address. You need some tools to test port accessibilty. Or you may want to test some email server address with port number.

Here we introduce a way to test port accessibility on windows 10 with telnet.

As Telnet by default is not opened in windows, for some security reason. You could refer this link to open telnet on your window 10 device.

After that, open one cmd window

telnet <ip/domain> <port>