List of well-known ports (computing)

Time you got around to sponsoring a child

IANA is responsible for assigning port numbers to specific uses. The well-known ports are those in the range 0-1023. On Unix-derived operating systems, opening a port in this range to receive incoming connections requires root privileges. Registered port numbers are those in the range 1024-49151. Port numbers in the range 49152-65535 are private or dynamic ports, not used by any defined application.

See the IANA list of port assignments for a full list.

List of network protocols, by port (not exhaustive, please extend and tidy)

20/tcp FTP The file transfer protocol - data
21/tcp FTP The file transfer protocol - control
22/tcp SSH Secure logins, file transfers (scp) and port forwarding
23/tcp Telnet non secure text communications
25/tcp SMTP Simple Mail Transfer Protocol (E-mail)
53/tcp DNS Domain Name Server
69/udp TFTP Trivial File Transfer Protocol
79/tcp finger Finger
80/tcp HTTP HyperText Transfer Protocol (WWW)
88/tcp Kerberos Authenticating agent
110/tcp POP3 Post Office Protocol (E-mail)
113/tcp ident old identification server system
119/tcp NNTP used for usenet newsgroups
143/tcp IMAP4 Internet Message Access Protocol (E-mail)
443/tcp HTTPS used for securely transferring web pages
591/tcp FileMaker 6.0 Web Sharing (HTTP Alternate, see port 80)

(entries above 1024 should probably go on a separate page)

1027/tcp ICQ Instant Messenger Client
1337/tcp WASTE Encrypted File Sharing Program
3306/tcp MySQL Database system
6000/tcp X11 used for X-windows
6667/tcp IRC, Internet Relay Chat
8080/tcp HTTP See Port 80. Often used when running a second web server on the same machine
31337/tcp Back Orifice Remote administration tool (often Trojan horse)