SFTP server log entries - An existing connection was forcibly closed by the remote host

+1 vote
asked Apr 21, 2016 by jb (240 points)

I'm testing your demo trial of the .Net SFTP library for CF 2.0 (RebexSftp-2016R1.1)

The sample runs fine, and i can log in a SFTP server, upload/download files, etc... but all the time that i disconnect the client i get an entry on the log server: 'An existing connection was forcibly closed by the remote host'.

I'm using your Rebex tiny SFTP server, but i already tried with other servers and the behaviour is the same.

Using another SFTP client (for instance FileZilla) i don't get the warning entry on the server and i get a graceful disconnect.

Applies to: Rebex SFTP
commented Apr 21, 2016 by Tomas Knopp (58,890 points)
Thank you for your bug report. I was able to reproduce the error with both the .NETCF 2.0 and 3.5 version of Rebex SFTP client components. We are looking for the solution, I will keep you updated about the progress and send you the solution hopefully by tommorow.
commented Apr 21, 2016 by Tomas Knopp (58,890 points)
I have more information - the bug is actually caused by a bug in .NET Compact Framework which reports that a packet was already sent, althouhg it actually was not. This results in our client closing the connection as it thought that the gracefull connection close request has already been sent, altough it was not.

We already came across this issue before in our FTP client component. Fortunatelly, adding a workaround is simple. We only have to wait for a small amount of time in the Disconnect method after we send the packet before closing the connection. I will send you a hotfix tommorow.

1 Answer

+1 vote
answered Apr 22, 2016 by Tomas Knopp (58,890 points)
edited Jul 1, 2016 by Lukas Pokorny
 
Best answer

This has been solved in Rebex SFTP 2016 R2.

As promised I've prepared the hotfix. Please download the SFTP fixed trial version, and give it a try.

commented Apr 22, 2016 by jb (240 points)
Hi Tomas,

I've done a few tests and now it seems to be working properly.
Thanks a lot for the effort and fast reply.
commented Apr 22, 2016 by Tomas Knopp (58,890 points)
Hi jb, you're welcome! It's nice to hear that it's working now.
...