WSAECONNRESET An existing connection was forcibly closed by the remote host.

Explains the meaning of the "WSAECONNRESET An existing connection was forcibly closed by the remote host." error and demonstrates a way to reproduce it by setting the "No Transfer Timeout" setting on a FileZilla FTP server to a very small value.

Download 32-bit Chilkat FTP2 ActiveX (.msi)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATFTP2Lib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ftp: TChilkatFtp2;
success: Integer;
i: Integer;
localFilename: String;
remoteFilename: String;

begin
ftp := TChilkatFtp2.Create(Self);

//  Any string unlocks the component for the 1st 30-days.
success := ftp.UnlockComponent('Anything for 30-day trial');
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);
    Exit;
  end;

ftp.Hostname := '192.168.1.108';
ftp.Username := 'myLogin';
ftp.Password := 'myPassword';

//  Connect and login to the FTP server.
success := ftp.Connect();
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);
    Exit;
  end;

ftp.Passive := 1;

//  In this example, we've set the FileZilla FTP Server's
//  "No Transfer Timeout" to 5 seconds.  This is a setting
//  on the FTP server (not in the Chilkat FTP component).
//  It causes the server to disconnect from the client after
//  5 seconds of no upload or download activity.  As you'll see,
//  sending commands over the control channel, such as
//  NOOP (no-operation) commands will have no effect.
//  It is an upload, download, or directory listing that is required.

//  This code will wait 10 seconds before proceeding with
//  the PutFile.  This should be enough time for the FileZilla
//  server to disconnect.

for i := 0 to 10 do
  begin
    //  Sleep for 1 second
    ftp.SleepMs(1000);

    //  Send a NOOP command to the FTP server.
    //  After about 5 iterations, it should fail and the LastErrorText
    //  will contain this message:
    //  WSAECONNRESET An existing connection was forcibly closed by the remote host.
    success := ftp.Noop();
    if (success <> 1) then
      begin
        Memo1.Lines.Add(ftp.LastErrorText);
        break;
      end;
  end;

//  What happens if we try to upload a file without an existing
//  connection?
//  Let's do it and find out...

//  Upload a file.
localFilename := 'c:/temp/hamlet.xml';
remoteFilename := 'hamlet.xml';

success := ftp.PutFile(localFilename,remoteFilename);
if (success <> 1) then
  begin

    //  In Active mode (i.e. non-passive), we get this error:
    //  "Failed to get socket's IP address. Socket may already be disconnected."
    //  In Passive mode, we'll get this error:
    //  " No socket exists for sending (2)"
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

ftp.Disconnect();

ShowMessage('File Uploaded!');
end;