1. After opening our Telnet service, select the command Start-Run-》cmd on the local computer.

2. Run our cmd command in the run option, and we will find a dialog box pop up on the computer.

3. Write the command "Telnet www.baidu.com 80" in the cmd command editor. It should be noted here that 80 is Baidu's 80 port.

4. After entering the above command, select Enter. If a new blank dialog box appears, it means that port 80 of Baidu website is open.

5 If the command "telnet www.baidu.com 3389" is entered in the cmd command, the dialog box displays "Connect to www.baidu.com".

Then the server where Baidu website is located has not started port 3889.