Before you start:
Objectives: Learn common services and port numbers and which transport protocol they make use of.
Prerequisites: You need to know about the TCP/IP protocols in general.
Key Terms: Network, port numbers, protocol, common, and services.
The network ports are actually given by the UDP or TCP protocols at the Transport layer. They’re utilized by the protocols in the OSI model’s upper layers. Eth port numbers are utilized for determining what protocol incoming traffic ought to be directed to.
Ports permit a single host with a single IP address for running the network services. Every port number recognizes a distinct service, and every host can, in fact, have 65535 ports for each IP address. Port use is actually regulated by the ICANN (Internet Corporation for Assigning Names and Numbers). By ICANN, there are actually three categories for the ports:
- From 0-1023: Renowned ports allocated to common services and protocols.
- From 1024-49151: Registered ports allocated by ICANN to a particular service.
- From 49152-65 535: The dynamic (high, private) ports range from 49,152-65,535. It can be utilized by any service on an ad-hoc basis. Ports are allocated when the session is set up and launched when the session ends.
Common Network Port Numbers:
Well, known ones are:
|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 System (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|
|989, 990||FTP over SSL/TLS (implicit mode)||TCP|
|3389||Remote Desktop Protocol||TCP and UDP|