CompTIA Network+ Practice Test

File Transfer Protocol (FTP) is designed specifically for transferring files and it utilizes two ports for its operations. TCP/21 is used for the control connection, where commands and responses are sent. TCP/20, on the other hand, is employed for the data transfer connection when sending files from the server to the client, typically in active mode. This separation of control and data connections is a fundamental characteristic of how FTP functions, allowing it to manage the transmission of files efficiently.

In contrast, the other protocols mentioned do not use TCP/20 for file transfers. HTTP, for example, operates primarily over TCP/80 (or HTTPS over TCP/443), focusing on delivering web content. SSH is used for secure command execution, typically on TCP/22, and IMAP is intended for email retrieval on TCP/143, neither of which involve file transfers in the manner characterized by FTP. Therefore, FTP’s specific use of TCP/20 for data transfer makes it the correct answer.