NcFTPd general.cf file configuration
Don't forget to restart NcFTPd after modifying the general.cf file.
This option enables or disables TCP/IP's "keep alive" function on the FTP control connection. In theory this could help prevent long-lived sessions from timing out while a long-lived transfer proceeds on the FTP data connection, but in reality this is not the case. The keep alive probes aren't sent soon enough -- the default implementation of TCP doesn't send them until several hours have elapsed. For this option to be effective, both the client and server operating systems would have to tune the TCP/IP stack to send the probes sooner, and it is unlikely that the client side will have done the tuning.
This option is enabled by default anyway, but you can change it if you like.