Which protocol runs over port 22 as a subsystem?

Which protocol runs over port 22 as a subsystem?

• A. SSH
• B. FTP
• C. SFTP
• D. Telnet

Answer: (C)

SFTP is the file transfer protocol that is implemented as a subsystem of SSH. SSH creates an encrypted channel over port 22, and SFTP operates inside that same SSH connection to transfer files securely without needing a separate port. This relationship—SFTP riding on the SSH transport—is why it uses port 22. In contrast, FTP uses port 21 with separate control and data connections, and Telnet uses port 23 and is not secure. SSH handles remote command execution, but SFTP is the dedicated file transfer mechanism within SSH, hence it runs over port 22 as a subsystem.

SFTP is the file transfer protocol that is implemented as a subsystem of SSH. SSH creates an encrypted channel over port 22, and SFTP operates inside that same SSH connection to transfer files securely without needing a separate port. This relationship—SFTP riding on the SSH transport—is why it uses port 22. In contrast, FTP uses port 21 with separate control and data connections, and Telnet uses port 23 and is not secure. SSH handles remote command execution, but SFTP is the dedicated file transfer mechanism within SSH, hence it runs over port 22 as a subsystem.