What is port address and its function
What is port address and its functionsPosted in: #Hacking and Security
@Issack Kalange Are you looking for the textbook definition?
In the internet protocol suite, a port is an endpoint of communication in an operating system.
A port is always associated with an IP address of a host and the protocol type of the communication. A port is identified for each address and protocol by a 16-bit number, commonly known as the port number.
Does this answer your question?
Think of port address as the unique 'door' where the other computers connected to the network can communicate with the host computer. It's a number that's generated by the operating system on the host computer.
Some of the port numbers are dedicated to specific functions and are universally agreed upon. For example, http works on port 80 and 25 is dedicated to SMTP. Now a days, http is being deprecated in favor of the more secure HTTPS (S stands for Secure) which works on port 443.
As @Jeffery Simon said, it's a 16 bit number, which means port numbers will range from 0 - 65,535. The initial port numbers, up to 1024 are typically reserved for the privileged services; like the ones I mentioned above.
I hope this gives you a better idea of port addresses (port numbers). Here's a list of some of the most commonly used port addresses -
Port Number ---
|1||TCP Port Service Multiplexer (TCPMUX)|
|5||Remote Job Entry (RJE)|
|18||Message Send Protocol (MSP)|
|20||FTP -- Data|
|21||FTP -- Control|
|22||SSH Remote Login Protocol|
|25||Simple Mail Transfer Protocol (SMTP)|
|42||Host Name Server (Nameserv)|
|49||Login Host Protocol (Login)|
|53||Domain Name System (DNS)|
|69||Trivial File Transfer Protocol (TFTP)|
|108||SNA Gateway Access Server|
|115||Simple File Transfer Protocol (SFTP)|
|137||NetBIOS Name Service|
|139||NetBIOS Datagram Service|
|143||Interim Mail Access Protocol (IMAP)|
|150||NetBIOS Session Service|
|179||Border Gateway Protocol (BGP)|
|190||Gateway Access Control Protocol (GACP)|
|194||Internet Relay Chat (IRC)|
|197||Directory Location Service (DLS)|
|389||Lightweight Directory Access Protocol (LDAP)|
|396||Novell Netware over IP|
|444||Simple Network Paging Protocol (SNPP)|