Although TCP/IP checks that all packets are received, malformed packets or other mishaps can occur, leading the FTP client to believe that a transfer was successful when it was not.
Secure FTP Server's file integrity command is defined as “XCRC”. Once an XCRC enabled client performs a transfer, it can request the server to do a checksum calculation on the file. If it matches the checksum on the client, then the transfer is deemed successful. However, performing XCRC checksum calculations are processor intensive so you will need to enable or disable it accordingly.
To enable file integrity (XCRC) checking
Start the Administrator Interface and connect to the Server.
At the bottom of the left pane, click the Server tab.
In the left pane, expand the Group, Server and Site to display the User Setting Level or user you want to configure.
Select the user or User Setting Level you want to configure.
In the right pane, click the Security tab.
Select Allow XCRC command to enable XCRC file integrity checking.
Click Apply.