SolarWinds | Serv-U
Contact Support: 866-530-8040 | Contact Sales: 855-498-4154 or email | Show Flags | Login
Serv-U FTP Server Home Page
The Best for Less
Secure file transfer & share files
from anywhere - affordably

FREE for 14 Days
Full featured trial with secure
FTP, file sharing & web transfer


Clear Command Channel (CCC)  -  KB Article #1495

Related Articles --

If the CCC command is sent by the client and accepted by the server during a secured session, the command channel will no longer be secured and will instead be sent in clear text. The data channel will still be secured according to the protection level set using the PROT command.

The CCC command is useful on client's requiring the usage of active (PORT) mode data transfers when they are behind a router that implements NAT. A clear command channel allows NAT to function on the router so that it can continue to "follow" the FTP transaction and alter the PORT command with an external IP address while preparing for the server's inbound connection on the port specified in that PORT command.

Common Responses
533, 534
500, 502, 421

See Also

  • AUTH
  • PROT
  • Securing FTP Behind a Router with FTP Voyager
  • About FTP Response Codes
  • FTP Commands
  • FTP Response Codes