Click "Start" → "Control Panel" → "Program", "in the program and function" to find and click on "Turn on or off Windows features" into the Windows Feature Settings dialog box. Locate and tick the Telnet client and Telnet server, and finally "OK" Wait a moment to complete the installation. In addition, we can install "TFTP client", "Internet information Service" and so on through the wizard.
When the installation is complete, the Telnet service is disabled by default. You also need to perform "start" → "Run", enter Servcies.msc (or perform "computer" → "admin" → "Services and Applications" → "services") to open the Service Manager. Locate and double-click the Telnet service entry, Set its startup mode to "manual" (more secure, only enabled when needed), and finally "start" the service "OK" to exit.
Enable the Telnet echo feature
First enter the command line interface: Enter Telnet
Next ENTER: Set Localecho
The system prompts for local echo enabled
Quit exit
I'm going to start a local tomcat as a test.
Then enter the command line: Telnet localhost 80
Then CTRL +], then do not enter any direct carriage return,
And then enter the command to see the Echo @_@
Telnet if you find that the input error cannot be Ge Qing except, you must re-enter it,
To view ports in Windows, you can use the netstat command:
Click "Start → run", type "cmd" and enter, and open a command prompt window. Type "Netstat-a-n" at the command prompt and press ENTER to see the port number and status of the TCP and UDP connections displayed in digital form.
Command format: Netstat-A??????
-A indicates that all active TCP connections and the TCP and UDP ports that the computer listens to are displayed.
-E Indicates the number of bytes sent and received by the Ethernet, the number of packets, and so on.
-N indicates that only the address and port number of all active TCP connections is displayed numerically.
-O indicates that the active TCP connection is displayed and includes the process ID (PID) for each connection.
-S indicates statistics for various connections by protocol, including port number
Netstat-an View all open ports
Netstat-n View the ports in the current connection
Close port
For example, to turn off the 25 port of the SMTP service in Windows 2000/XP, you can do this by opening Control Panel first, double-clicking Administrative Tools, and then double-clicking Services. Then locate and double-click the simple Mail Transfer Protocol (SMTP) service in the Open Services window, click the Stop button to stop the service, and then select Disabled in Startup Type, and then click OK. In this way, shutting down the SMTP service is equivalent to shutting down the corresponding port.
Open port
If you want to open the port, you can enable the port by clicking the "Start Type" option, clicking the "OK" button, and then opening the service, in the service status, click the Start button, and then click OK.
Tip: There is no "service" option in Windows 98, you can use the firewall's rule setting function to turn off/open the port.