1. Review and close the port in the command prompt window
Input netstat -a -n view TCP and UDP ports and their respective state as
-a displays all connections and listening ports.
-n Display addresses and port numbers in digital form.
Use netstat -aon! Findstr "8080" to close port 8080
2.
Close ports
Open the Control Panel - Open Administrative Tools - Click service - select a service SMTP, click "Stop" - select "Disabled" in the Startup Type - Click OK to close the SMTP port services
Open ports only need to click the "Automatic" and click "OK" and then open the service click "Start" to start the port in the "Startup type" and finally click "OK"
3. The most simple and convenient it is to use firewall software, Skynet, Jinshan, || S, etc.
There are a few common port, port 25 is used by SMTP server, port 21 is used for FTP, HTTP 80 port is mainly used for web surfing