| require-implicit-ack-for-downloads |
NcFTPd general.cf file configuration Don't forget to restart NcFTPd after modifying the general.cf file. |
By default, NcFTPd requires implicit acknowledgment of downloads before creating a log entry. The remote user implicitly acknowledges a successful download by doing something else in the FTP session, such as changing to another directory or downloading another file, or even issuing a QUIT command to close the session. This allows NcFTPd to differentiate between transfers which were definitely received in entirety by the user, and those where NcFTPd sent the entire data file to the remote client's machine but the FTP client program closes the session abruptly. Such behavior often indicates that the data was sent to the remote client machine's TCP layer, but did not reach the FTP client program because it exited.
A problem with implicit acknowledgments is that the log entry for the download will no longer appear in near-real time. Instead, the xfer log entry is created when the user acknowledges or the FTP session times out. This option allows you to disable implicit acknowledgment so the log entries appear immediately with the trade-off that you cannot be sure if the user really received the entire file.
Examples:
Recommendation:
