Something on the WinSCP client end is causing the server to issue a new key...not sure what condition causes it though?
That's not likely. Are you saying that other SFTP (not FTP) clients get the same host key all the time, while WinSCP not? Do you have logs that show that?
Actually, YES other SFTP (not FTP) clients get and can use the same host key all of the time, but those clients are also ALL using WinSCP. So in this situation, we have multiple WinSCP "clients" (all at the same version) connecting to one single WingFTP Server (https://www.wftpserver.com/
), but only ONE particular "client" seems to be getting a totally new Key on a daily basis.
Logs are easy to get. Attached is the WinSCP Log from the server that experiences the issue (ServerGetsNewKey.log), as well as the WinSCP Log from a server that does NOT experience the issue (ServerKeepsKey.log). Assuming that the problem isn't with WinSCP and isn't our WingFTP server itself (I have a case open with them as well), what networking property could exist that would cause this behavior?
In other words, what common network firewall or filter rule would cause the server to be told that a new SSH key exists every morning, and not just every time we connect? The server that's told it has a new key every day, is behind a FortiGate (https://www.fortinet.com/
) Stateful Firewall. Is there something specific in this firewall brand that would cause this behavior?