CompTIA Security+ All-in-One Exam Guide (Exam SY0-301), 3rd Edition, 3rd Edition

FTP/FTPS/SFTP

One of the methods of transferring files between machines is through the use of the File Transfer Protocol (FTP). FTP is a plain text protocol that operates by communicating over TCP between a client and a server. The client initiates a transfer with an FTP request to the server’s TCP port 21. This is the control connection, and this connection remains open over the duration of the file transfer. The actual data transfer occurs on a negotiated data transfer port, typically a high order port number. FTP was not designed to be a secure method of transferring files. If a secure method is desired, then one can use FTPS or SFTP.

FTPS is the use of FTP over an SSL/TLS secured channel. This can be done either in explicit mode, where an ...