Personal tools
You are here: Home → Network Services → FTP
 

FTP

When using FTP (File Transfer Protokol) to exchange files with servers outside the Garching MPG Campus you may experience a problem: Although the initial connection works you cannot retrieve any data, not even a directory listing.

  Background: FTP uses two connections: The control-connection is opened by your client (internal) to the external server. Then the server tries to open the data-connection to an arbitrary port on your client. This doesn't work because incoming connections to arbitrary ports are blocked.

Workarounds:

  • Use passive mode if your client supports it. In passive mode the data-connection is opened by the client, too. Examples:
    • For WS-FTP (Windows) activate passive transfers under connect arrow advanced.
    • FTP on Linux has a command line switch (-p).
    • For FTP on AIX use the ftp command "passive".
    • Web browsers use passive mode by default, on the commandline try "wget".

     

  • Otherwise use the FTP gateway. Example:
    Instead of

    $ ftp ftp.some.where
    Name: anonymous

    use

    $ ftp ftp-gw.rzg.mpg.de
    Name: anonymous@ftp.some.where

Document Actions