FTP data uses which TCP port for communication?

FTP, or File Transfer Protocol, is used for transferring files between a client and server over a network. The operation of FTP relies on two distinct channels for communication: the command channel and the data channel.

The command channel uses TCP port 21, while the data channel is established using TCP port 20. When a client initiates a connection to an FTP server to request a file transfer, it typically sends commands over port 21. Once the server responds and prepares to send the requested data, it does so on port 20.

Understanding this distinction is crucial for comprehending how FTP manages file transfers. The use of a separate port for data transfer allows FTP to handle multiple connections simultaneously and facilitates efficient communication between the client and server.