Site-to-Site Transfers (FXP)

Separate CONTROL and DATA connections allows transmitting data not only between client and server; it allows a client to control two FTP servers at once and transfer data between them by issuing a PASV command on one server and then a matching PORT command on the other. Thus, one server connects to the other instead of to a client. This behavior is not a hack; it is part of the official FTP specs. Today, it is widely known as FXP. The chart below shows servers that support FXP.

To perform a site-to-site transfer

  1. Connect to each site (source and destination).

  2. On the main menu, click Window > Tile.

  3. Drag the file from one Remote Pane to another. The Queue pane displays a double arrow (<->), to indicate a site-to-site transfer.

To display more than one remote site at a time

  1. Connect to two or more sites.

  2. On the main menu, click Window > Cascade or Tile.

  3. To return to the default, tabbed view, click Maximize in the upper right of any remote pane.

  • If you are transferring between sites with SSH2 or SSL connections, transfers between them are not secure unless both servers support SSCN.

  • Because site-to-site transfers are considered a security risk, many servers do not support them or optionally decline to do so. The following table displays supporting servers.

BLUE servers must be present for successful site-to-site transfer.

RED servers make site-to-site transfers impossible.

BLACK servers can perform site-to-site transfers if a BLUE server is on the other side.

A site-to-site transfer with at least one RED server or two BLACK servers will fail.

 

  

You can configure the ProFTPD 1.2.3 Orc3 server, the wu-ftpd 2.6.0 server and the MS IIS 5.0 server to allow FXP.