Ports used by FTP

0 votes
asked Dec 13, 2010 by Martin House (570 points)
edited Feb 8, 2011

Hi Everyone, I know that the default port used by FTP is port 21 - are there any other ports used ?

I have in the back of my mind that there are separate control and data ports - is that correct.

Thanks for your help

Martin

Applies to: Rebex FTP/SSL

1 Answer

0 votes
answered Dec 13, 2010 by Martin Vobr (12,940 points)
edited Dec 14, 2010
 
Best answer

The FTP uses two communication channels: control connection and data connection.

Control connection

  • Control connection is established on a well-known port.
  • Is used for sending commands to the FTP server.

Control connections use the following ports:

  • port 21 - plain old FTP
  • port 21 - FTP over TLS/SSL Explicit mode
  • port 990 - FTP over TLS/SSL Implicit mode

Data connection

  • Used for upload, download, and directory listing transfer.
  • Initiated either by the FTP client (passive mode) or by the FTP server (active mode)
  • Established on random port. In passive mode, the port is selected by the FTP server. In active mode, it is selected by the FTP client.

See the following links for more info:

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