SteelHead are aware of FTP connections in either active or passive mode, and they correlate the data channels with the control channel.

By default, FTP uses the standard optimization rule for in-path rules. If you use manual optimization rules, follow the standard in-path practice, configuring the client-side SteelHead in-path rules based on IPs or TCP port. With the TCP port, it is only necessary you specify destination port 21, which automatically includes optimization for the data channels, regardless of whether active or passive mode is used.

To pass through FTP, Riverbed recommends creating pass-through rules based on the FTP server IP, on both the client-side and server-side SteelHeads. You base the rules this way because of varying data connection behavior depending on active or passive mode. Because the source of the data connection is the FTP server in active mode, it is necessary to configure the in-path pass-through rules on the server-side SteelHead—this is unlike other protocols.