Definition
FTP, short for File Transfer Protocol, is a standard network protocol used to transfer files between a client and a server over a TCP/IP network. It allows users to upload, download, rename, and delete files on remote servers, making it one of the oldest and most widely recognized methods of file sharing across networks.
FTP typically operates through a client application that connects to an FTP server using credentials. While it has been largely replaced by more secure methods, it remains in use for legacy systems, website management, and file distribution.
Advanced
FTP operates over TCP, typically on ports 20 and 21. It supports two modes: active and passive. Active mode requires the server to establish a data connection back to the client, while passive mode lets the client initiate both connections, helping navigate firewalls and NAT (Network Address Translation).
However, standard FTP does not encrypt traffic, leaving data and credentials exposed. Secure alternatives such as FTPS (FTP Secure, which uses SSL/TLS) and SFTP (SSH File Transfer Protocol, though technically a different protocol) are preferred in modern environments. Advanced file transfer setups often include automation, logging, and integration with enterprise workflows.
Why it matters
- Provides a reliable method for transferring large files.
- Supports remote file management for websites and applications.
- Remains essential for legacy systems and compatibility.
- Offers standardized functionality across platforms.
- Can be automated for recurring file exchange tasks.
Use cases
- A web developer uploading files to a hosting server.
- A company distributing software updates via FTP servers.
- Enterprises exchanging large data sets with partners.
- Automated backup systems sending files to remote storage.
Metrics
- File transfer speed and throughput.
- Transfer success and failure rates.
- Server uptime and availability.
- Authentication success rate.
- Data integrity verification after transfer.
Issues
- Lacks encryption, making data vulnerable in transit.
- Firewall and NAT configurations can complicate connections.
- Poor security may allow unauthorized access if not properly configured.
- Largely outdated due to the rise of secure alternatives.
Example
A hosting provider offered FTP access for customers to manage website files. To address security risks, the provider transitioned to FTPS, ensuring all file transfers were encrypted while retaining FTP’s familiar functionality.