<div dir="ltr">you could also try to fire Filezilla from cli with verbos turned up and piped to a log file locally. May uncover a clue. Since you are connecting via ssh you might try cli sftp connection as well to help isolate program issue or system issue.<div> </div><div>-- Fred</div></div><div class="gmail_extra"> <div class="gmail_quote">On Thu, Jun 1, 2017 at 6:13 PM, Peter Flynn <<a href="mailto:peter@silmaril.ie" target="_blank">peter@silmaril.ie</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 06/01/2017 09:27 PM, Rog wrote: > I rely on Filezilla to transfer files to my hosting service but it no > longer works. It fails at the very beginning, failing to connect. Much > searching w/ Google turns up no answers. Nor does a tech support > consultation with the hosting service. The failure is NOT due to wrong > username or password as I can establish ssh connections from the CLI. It's worrying when this happens, but hosting services are notorious for changing things which don't affect Mac or Windows users, but which may affect Linux users. >From what you quote below it looks like it's having trouble identifying which key exchange (kex) algorithm to use: the server wants you to use diffie-hellman-group-exchange-sha256 but Konqueror can only use one of <a href="mailto:curve25519-sha256@libssh.org">curve25519-sha256@libssh.org</a> ecdh-sha2-nistp256 diffie-hellman-group14-sha1 diffie-hellman-group1-sha1 This post <a href="https://ubuntuforums.org/showthread.php?t=2297006" rel="noreferrer" target="_blank">https://ubuntuforums.org/showthread.php?t=2297006</a> (different circumstances and different software) explains how to find out what algorithms are supported, but it's a couple of years old. At a wild random guess the hosting company has changed things so that they only support diffie-hellman-group-exchange-sha256, so you'll need an sftp client that supports that method of key exchange. Obviously FileZilla doesn't. Can you try again and note the EXACT date and time, then call tech support and ask them to check the access logs (eg /var/log/secure) to find out if they can see a request coming in from your IP address, and being rejected. If you search Mr Google for filezilla diffie-hellman-group-exchange-sha256 you will gets lots of pages about this problem, so it seems to be well known. Several posts make the suggestion along the lines of: > FileZilla's SFTP support is based on PuTTY's psftp. If you change the > default key exchange cipher priorities in PuTTY, it should also > affect FileZilla. but this may only apply to Windows clients. I'm afraid I don't have a solution (and I just hope my own hosting provider doesn't make the same move, although I only use FZ very rarely, as sftp from the command line is fine for my own use). ///Peter <div class="HOEnZb"><div class="h5"> > Konqueror also fails to connect and gives the following, more detailed > error: > > The requested operation could not be completed > > Details of the Request: > URL: sftp:// [redacted] > Protocol: sftp > Date and Time: Thursday, June 01, 2017 04:18 PM > Additional Information: kex error : no match for method kex algos: > server [diffie-hellman-group-exchange-sha256], client > [<a href="mailto:curve25519-sha256@libssh.org">curve25519-sha256@libssh.org</a>,ecdh-sha2-nistp256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1] > Description: > kex error : no match for method kex algos: server > [diffie-hellman-group-exchange-sha256], client > [<a href="mailto:curve25519-sha256@libssh.org">curve25519-sha256@libssh.org</a>,ecdh-sha2-nistp256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1] > > I note that I've gone so far as deleting all Filezilla-related files and > re-installing it as well as deleting my known hosts file, to no avail. > So I turn to this list in desperation. I would really like to continue > to use Filezilla because it's fast and easy. > > -- > Roger > <a href="mailto:linux.rog@gmail.com">linux.rog@gmail.com</a> > > > </div></div>-- xubuntu-users mailing list <a href="mailto:xubuntu-users@lists.ubuntu.com">xubuntu-users@lists.ubuntu.com</a> Modify settings or unsubscribe at: <a href="https://lists.ubuntu.com/mailman/listinfo/xubuntu-users" rel="noreferrer" target="_blank">https://lists.ubuntu.com/mailman/listinfo/xubuntu-users</a> </blockquote></div> </div>