The known port numbers

Similar to IP addresses, ports are also divided into classes. There are three port ranges: the known ports, the registered ports and the dynamic / private ports.

The assignment of port numbers, the regional assignment of IP addresses and DNS root zones (Domain Name System) are managed by IANA (Internet Assigned Numbers Authority). IANA also maintains a central repository for protocol names and the registry used for internet protocols.

The following table lists some of the more common, well-known port numbers.

Port numberAssignment
20File Transfer Protocol for data transfer
21File Transfer Protocol for command management
22Secure Shell for secure authentication
23Telnet remote authentication service for unencrypted text messages
25Simple Mail Transfer Protocol for email routing
53Domain Name System service
80Hypertext Transfer Protocol for use on the web
110Post Office Protocol
119Network News Transfer Protocol (NNTP)
123Network Time Protocol (NTP)
143Internet Message Access Protocol for managing digital email
161Simple Network Management Protocol
194Internet Relay Chat (IRC)
443HTTP and HTTPS over TLS / SSL