Getting Disconnected by the server ('Key exchange timed out') Error.

Question

As we are using rebex sftp to upload and download and currently we are started getting a key exchange timed-out error, so can you please help me to identify the root cause for the same. Here I am adding a stack trace.

Rebex.Net.SftpException: Disconnected by the server ('Key exchange timed out').
---> Rebex.Net.SshException: Disconnected by the server ('Key exchange timed out').
at Rebex.Net.SshSession.kzrwr(dinkh p0, Boolean p1)
at Rebex.Net.SshChannel.winmt(Byte[] p0, Int32 p1, Int32 p2)
at Rebex.Net.SshChannel.Send(Byte[] buffer, Int32 offset, Int32 count)
at cmhho.rozsz.ajqlw(dinkh p0, feuge p1)
at cmhho.rozsz.vdbkd(dinkh p0, UInt32 p1, ryzia p2, feuge p3)
at cmhho.rozsz.vqgyk(String p0, Boolean p1, Boolean p2, Boolean p3, Boolean p4, ermem p5, shqnp& p6, feuge p7)
at Rebex.Net.Sftp.aixik(String p0, Boolean p1, Boolean p2, Boolean p3, Boolean p4, feuge p5)
--- End of inner exception stack trace ---
at Rebex.Net.Sftp.aixik(String p0, Boolean p1, Boolean p2, Boolean p3, Boolean p4, feuge p5)
at Rebex.Net.Sftp.ruoge(String p0, feuge p1)
at Rebex.Net.Sftp.hbinw(Object p0, Enum p1, Object[] p2)
at cmhho.ljwiz.uovpb(Object p0)
--- End of stack trace from previous location ---

Comments

Does it occur while connecting to the server, or during a file transfer?
Would it be possible to create a log file (as described at https://www.rebex.net/kb/logging/ ) and mail it to us for analysis?

Answer 1

This log is occurring while we are checking file exists or not using Sftp.

if (objSftp.IsConnected && objSftp.IsAuthenticated)
{

isExist = await objSftp.FileExistsAsync(destFileName);
}

As at the server side we are getting log-like
Debug SSH: Session 90555: Performing algorithm negotiation and key exchange.

Comments

Does this mean that you use Rebex File Server library at the server side as well? What version/platform is it? Also, which version of Rebex SFTP do you use at the client side?

---

Yes, that's right we are using rebex file server on the server side and the version of that is 7.0.8581.0, and on the client side rebex sftp version is 7.0.8581.0.

---

Please create client-side a debug log using Sftp object's LogWriter property (as described at https://www.rebex.net/kb/logging/ ) and either post it here or mail it to support@rebex.net for analysis - that will hopefully make it possible to tell what is going on.