The PROT subcommand defines the protection used for FTP data connections (which are used to transmit directory listings and file data). The syntax of this subcommand is:
PROT [ C | P ]
Parameter values:
| C | Clear. The data connection carries "raw data" of the file transfer with no security applied. |
| P | Private. The data connection will use Transport Layer Security (TLS) or Secure Socket Layer (SSL), which provides Integrity and Confidentiality protection. |