File Transfer Protocol, often abbreviated as FTP, is a standard network protocol used for transmitting files over the internet[1]. It was developed by Abhay Bhushan and initially published as RFC114 back in 1971. The protocol establishes a connection between a client and a server, allowing for the transfer of data. It operates in both active and passive modes and corresponds with three-digit status codes. FTP, however, is not inherently secure and has several known vulnerabilities, including susceptibility to brute-force and FTP bounce attacks. Over the years, it has evolved to support IPv6 and extended passive mode. There are also secure alternatives to FTP, such as SFTP and SSH FTP. Users can access FTP servers through various software applications, web browsers, and FTP URLs.
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data connections between the client and the server. FTP users may authenticate themselves with a plain-text sign-in protocol, normally in the form of a username and password, but can connect anonymously if the server is configured to allow it. For secure transmission that protects the username and password, and encrypts the content, FTP is often secured with SSL/TLS (FTPS) or replaced with SSH File Transfer Protocol (SFTP).
Communication protocol | |
Purpose | File transfer |
---|---|
Developer(s) | Abhay Bhushan for RFC 114 |
Introduction | April 16, 1971 |
OSI layer | Application layer |
Port(s) | 21 for control, 20 for data transfer |
RFC(s) | RFC 959 |
The first FTP client applications were command-line programs developed before operating systems had graphical user interfaces, and are still shipped with most Windows, Unix, and Linux operating systems. Many dedicated FTP clients and automation utilities have since been developed for desktops, servers, mobile devices, and hardware, and FTP has been incorporated into productivity applications such as HTML editors and file managers.
An FTP client used to be commonly integrated in web browsers, where file servers are browsed with the URI prefix "ftp://
". In 2021, FTP support was dropped by Google Chrome and Firefox, two major web browser vendors, due to it being superseded by the more secure SFTP and FTPS; although neither of them have implemented the newer protocols.