Ports That used for Services
The ports used for giving path to enter in the system. A port is an endpoint of communication. All the connections are (terminated) at ports of hardware devices.A port number is always associated with an IP address of a host and the protocol type of the communication.It completes the destination or origination network address of a message. Specific port numbers are commonly reserved to identify specific services, so that an arriving packet can be easily forwarded to a running application. For this purpose, the lowest numbered 1024 port numbers identify the historically most commonly used services, and are called the well-known port numbers.
Common port numbers:-
The Internet Assigned Numbers Authority (IANA) is responsible for the global coordination of the DNS Root, IP addressing, and other Internet protocol resources. This includes the registration of commonly used port numbers for well-known Internet services.
The port numbers are divided into three ranges: the well-known ports, the registered ports, and the dynamic or private ports.
The well-known ports (also known as system ports) are those from 0 through 1023. The requirements for new assignments in this range are stricter than for other registrations.
|Port||Service name||Transport protocol|
|20, 21||File Transfer Protocol (FTP)||TCP|
|22||Secure Shell (SSH)||TCP and UDP|
|25||Simple Mail Transfer Protocol (SMTP)||TCP|
|53||Domain Name Server (DNS)||TCP and UDP|
|67, 68||Dynamic Host Configuration Protocol (DHCP)||UDP|
|69||Trivial File Transfer Protocol (TFTP)||UDP|
|80||HyperText Transfer Protocol (HTTP)||TCP|
|110||Post Office Protocol (POP3)||TCP|
|119||Network News Transport Protocol (NNTP)||TCP|
|123||Network Time Protocol (NTP)||UDP|
|135-139||NetBIOS||TCP and UDP|
|143||Internet Message Access Protocol (IMAP4)||TCP and UDP|
|161, 162||Simple Network Management Protocol (SNMP)||TCP and UDP|
|389||Lightweight Directory Access Protocol||TCP and UDP|
|443||HTTP with Secure Sockets Layer (SSL)||TCP and UDP|
Use in URLs:-
Port numbers are sometimes seen in web or other uniform resource locators (URLs). By default, HTTP uses port 80 and HTTPS uses port 443, but a URL like http://www.somethingexample.com:8080/path/ specifies that the web browser connects instead to port 8080 of the HTTP server.