Both devices must be configured to transfer files via FTP. Port numbers consist of 16- bit numbers.įor example, a user request for a file transfer from a client, or local host, to a remote server on the internet uses File Transfer Protocol ( FTP) for the transaction. Port numbers are part of the addressing information that helps identify senders and receivers of information and a particular application on the devices. This identifying information enables devices to communicate over the internet. Any device connected to the internet is assigned a unique IP address for identification. An IP address identifies a machine in an IP network and determines the destination of a data packet, while port numbers identify particular applications or services on a system.Īn IP address is a logical address used to identify a device on the network. Port numbers identify a particular application or service on a system. What is the difference between an IP address and a port number?Īn IP address identifies a machine in an IP network and is used to determine the destination of a data packet. Once known as socket numbers, the early incarnation of port numbers is similar to the Internet Protocol ( IP) address class used today.
Hypertext Transfer Protocol ( HTTP) messages, for example, always go to port 80 - one of the most commonly used ports.ĭevelopers of the Advanced Research Projects Agency Network, an informal cooperation of system administrators and software authors, proposed the concept of port numbers. These numbers are reserved for certain protocols and their associated function.
All network-connected devices come equipped with standardized ports that have an assigned number. A port number is a way to identify a specific process to which an internet or other network message is to be forwarded when it arrives at a server.