An existing connection was forcibly closed by the remote hos (wodFtpDLX / wodFtpDLX.NET)

by Tau, Friday, August 28, 2015, 15:47 (3375 days ago)

Hello

We are using FtpDLX.NET 1.8.0.231 and we've started to get errors during the transmission of a big file (50Mb). The target server would accept about 50% of the file, then drop connection with this error:

An existing connection was forcibly closed by the remote host

We tested file upload with Filezilla and it works correctly (uploads 100%). I assume it could be an encryption/cipher issue with FtpDLX.NET.

The remote SFTP server uses the following encryption settings:

09:55:15 Trace: We claim version: SSH-2.0
09:55:15 Trace: Server version: SSH-2.0
09:55:15 Trace: Using SSH protocol version 2
09:55:15 Trace: Doing ECDH key exchange with curve nistp256 and hash SHA-256
09:55:15 Trace: Host key fingerprint is:
09:55:15 Trace: ssh-rsa 2048 *****
09:55:15 Trace: Initialised AES-256 SDCTR client->server encryption
09:55:15 Trace: Initialised HMAC-SHA-256 client->server MAC algorithm
09:55:15 Trace: Initialised AES-256 SDCTR server->client encryption
09:55:15 Trace: Initialised HMAC-SHA-256 server->client MAC algorithm

Our C# initialization code is this:

Ftp1.Hostname = hostname;
Ftp1.Login = login;
Ftp1.Password = password;
Ftp1.Port = port;
Ftp1.Protocol = Protocols.SFTP;
Ftp1.Authentication = Authentications.Password;
Ftp1.Encryption = EncryptionMethods.Auto;
Ftp1.KeepAlive = 3;             

Ftp1.Blocking = true;
Ftp1.Timeout = 5000;

Ftp1.Passive = true;
Ftp1.Compression = 0;
Ftp1.TransferMode = TransferModes.Binary;

...
//We are sending file from a memory stream
byte[] contents = new byte[size];
using (MemoryStream ms = new MemoryStream(contents))
{
      ftp.PutFile(ms, "/incoming/test.csv");                            
}

Unfortunately, we cannot provide access to that server - it's one of our clients' and it's IP protected.

Any ideas about this issue? Does FtpDLX.NET support the above encryption/cipher?

Thank you!