FTP: File Transfer Protocol
FTP (File Transfer Protocol) is a standard network protocol used to transfer files from one host to another over a TCP-IP based network, such as the internet. Here is a detailed overview:
History
- FTP was first proposed on April 16, 1971, by Abhay Bhushan in RFC 114.
- The initial specifications were detailed in RFC 114 and later revised in RFC 765 in June 1980.
- Over time, FTP has been updated with numerous RFCs to improve functionality and security.
Functionality
- Client-Server Model: FTP operates on a client-server architecture where the client initiates a connection to the server for file transfer.
- Two Channels: FTP uses two separate channels for communication:
- Control Connection: Used for sending commands and responses. This connection remains open for the duration of the session.
- Data Connection: Opened temporarily to transfer file data, closing after each file transfer or directory listing.
- Commands: FTP has a set of commands like PUT (upload), GET (download), LIST (list directory), etc., which are used to manage file transfers.
- Authentication: Traditional FTP uses clear-text passwords, but secure methods like SFTP or FTPS provide encryption for authentication.
Security Considerations
- FTP in its basic form transmits data unencrypted, making it susceptible to eavesdropping.
- Extensions like FTPS (FTP Secure) and SFTP (SSH File Transfer Protocol) were developed to add security layers:
- FTPS uses SSL/TLS for security.
- SFTP runs over an encrypted SSH session.
Use Cases
- Uploading and downloading files from a web server.
- Backing up files to a remote server.
- Transferring files between computers that are not on the same network.
Modern Usage and Alternatives
- Despite its age, FTP is still widely used due to its simplicity and the availability of clients for almost all operating systems.
- However, due to security concerns, many organizations are moving towards more secure alternatives like SFTP, FTPS, or cloud-based file transfer services.
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