Which TCP port is used for FTP data transfer?

File Transfer Protocol (FTP) utilizes two primary ports for its operations. For data transfer, FTP specifically uses port 20. This port is designated for establishing data connections during FTP sessions. When a client initiates a file transfer, the server opens a secondary connection on port 20 to transmit the data, while control commands are sent over port 21.

Recognizing the distinction between these ports is crucial in understanding how FTP functions. Although port 21 is essential for managing the control signals, the actual data exchange occurs over port 20. This division is a fundamental aspect of FTP's operation and is vital for network configurations and troubleshooting related to file transfers.