Computer port number: 0-65535 (256 * 256) 2 1 port: mainly used for FTP service. Port 25: open to SMTP server, mainly used for sending mail. Now, most mail servers use this protocol. Port 53: opened by DNS server, mainly used for domain name resolution. DNS service is the most widely used service in NT system. Ports 67 and 68: Ports are opened by the Bootstrap Protocol Server and the Bootstrap Protocol Client serving Boop. Port 69: It is a simple file transfer protocol developed for Cisco, similar to FTP. Port 79: open for Finger service, mainly used to query the online users of the remote host, operating system type, buffer overflow and other details. Port 80: It is open to HTTP, which is the most commonly used protocol for accessing the Internet and is mainly used to transmit information on WWW services. Port 99: It is used for a service called Metasyntax Relay (sub-game delay), which is relatively rare and generally not used. 109, 1 10 port: 109 port is open for POP2 service, 1 10 port is open for POP3 service, and POP2 and POP3 are mainly used for receiving mail. Port 1 10: It is an open port of SUN's RPC service and is mainly used for internal process communication of different computers in a distributed system. RPC is a very important component in various network services.

Port 1 13: It is mainly used for "authentication service" of Windows. Port 1 19: open to network news transfer protocol (NNTP).

Port 135: It is mainly used to provide DCOM services by using RPC protocol. Port 137: mainly used for "NetBIOS name service".

Port 139: provided for NetBIOS session service, mainly used to provide access to Windows files and printers and Samba services in Unix.

Port 143: Port 143 is mainly used for Internet Message Access Protocol V2 (IMAP for short).

16 1 port: 16 1 port is used for Simple Network Management Protocol (SNMP).

Port 443: Port 43 is a web browsing port, mainly used for HTTPS service, and is another HTTP that provides encryption and transmission through a secure port. Port 554: By default, port 554 is used for Real-time Streaming Protocol (RTSP). Port 1024: In general, port 1024 is not fixed as a service, but is interpreted as "Reserved" in English. Port 1080: Port 1080 is the port used by Socks proxy service. The WWW service that people usually use on the Internet uses the proxy service of HTTP protocol. Port 1755: Port 1755 is used for "Microsoft Media Server" (MMS for short) by default. 4000 port: 4000 port is used for QQ chat tools that people often use, specifically, it is the open port of QQ client, and the port used by QQ server is 8000. Port 5554: On April 30th this year, it was reported that a new worm appeared, worm. Sasser, appear for the lsass service of Microsoft. This virus can use TCP 5554 port to open FTP service, which is mainly used to spread the virus.

Port 5632: Port 5632 is the port opened by the familiar remote control software pcAnywhere. 8080 port: 8080 port, like 80 port, is used for WWW proxy service and can realize web browsing.