CCC (Clear Command Channel)
The CCC IBM® i FTP client subcommand changes the transmission mode in a control connection from the encrypted mode to the clear-text mode.
FTP client subcommand
CCC
FTP supports two kinds of transmission modes: the clear text mode and the encrypted mode. If you use the clear text mode in an FTP control connection , you take the risk of exposing your sensitive information to an intruder. If you use the encrypted mode, the firewall is not able to monitor or change the information sent within the FTP control connection. Thus the firewall cannot perform some functions such as network address translation.
The Clear Command Channel (CCC) subcommand changes the transmission mode in a control connection from the encrypted mode to the clear text mode. Thus, you can secure sensitive information including your user name and password by sending them in the encrypted mode. Then you can use the CCC subcommand to change the transmission mode to the clear text mode and send the port and IP information.
After using the CCC subcommand, you send all your information in the clear text mode in the control connection. If the names of files or directories on your system contain sensitive information, be aware that any names sent on the control connection after running the CCC subcommand are not protected. However, the data connection transmission mode remains intact and the data transfer that happens afterward is still secure.
Customers can either allow or disallow an individual user to use CCC by granting the private authority to QIBM_QTMF_CLIENT_REQ_10 through System i® Navigator Application Administration support or through the Change Function Usage (CHGFCNUSG) command; for example,
CHGFCNUSG FCNID(QIBM_QTMF_CLIENT_CCC) USER(user) USAGE(*ALLOWED)