How to set the computer port?

Usually, the system can set which ports are closed, but it cannot set which ports are open. At the beginning-> Enter netstat -a at runtime to see which ports are open on the computer. How to close the port: each service corresponds to the corresponding port. For example, as we all know, the port of WWW service is 80, smtp is 25 and ftp is 2 1. These services are all started by default in win2000 installation. Individual users are really unnecessary. Closing a port means closing useless services. In the control panel "Administrative Tools" in "Services". 1. Close port 80: Close the WWW service. The name displayed in "Service" is "World Wide Web Publishing Service", which provides web connection and management through the snap-in of Internet information services. 2. Close port 25: Close the Simple Mail Transfer Protocol (SMTP) service, which provides the function of sending e-mail across the network. 3. Close port 2 1: Close the FTP publishing service and provide FTP connection and management through the Internet information service management unit. 4. Close port 23: Close the Telnet service, which allows remote users to log on to the system and run console programs using the command line. 5. It is also important to shut down the server services that provide RPC support, file, print and named pipe sharing. Turning it off will turn off the default shares of win2k, such as ipc$, c$, admin$, etc. Turning off this service will not affect your sharing operation. 6. The other port is 139, which is a NetBIOS session port for file and print sharing. Note that the unix machine running samba has also opened the 139 port, which has the same function. In the past, streamer 2000 was not very accurate in judging the host type of the other party. It is estimated that the 139 port is open, and it is considered to be an NT machine, but it is ok now. The way to turn off 139 listening is to select the Internet Protocol (TCP/IP) attribute in the LAN connection in the network and dial-up connection, enter the advanced TCP/IP settings and WINS settings, and there is an item "Disable NETBIOS of TCP/IP", and then tick off the 139 port. For individual users, it can be set to "Disabled" in various service attribute settings to avoid restarting the service and opening the port next time.