FluentFTP - 连接时出错“尝试从套接字流中读取数据超时！”

Question

Getting

Timed out trying to read data from the socket stream!

when connecting to FTP using FluentFTP.

Below is the source code which I am using to connect:

Console.WriteLine("Configuring FTP to Connect to {0}", hostname);
ftp = new FtpClient(hostname,port,new NetworkCredential(username,password));               
ftp.ConnectTimeout = 600000;               
ftp.ReadTimeout = 60000;
ftp.EncryptionMode = FtpEncryptionMode.Explicit;
ftp.SslProtocols = System.Security.Authentication.SslProtocols.Tls;
ftp.ValidateCertificate += new FtpSslValidation(OnValidateCertificate);
ftp.Connect();
Console.WriteLine("Connected to {0}", hostname);

ftp.SetWorkingDirectory(foldername);
Console.WriteLine("Changed directory to {0}", foldername);

void OnValidateCertificate(FtpClient control, FtpSslValidationEventArgs e)
{
    // add logic to test if certificate is valid here
    e.Accept = true;
}

---

FileZilla log file for successful connectivity. I am able to connect the location via FileZilla. Snippet of log is below:

2017-12-08 13:34:33 17672 1 Status: Connecting to xx.xx.xx.xx:990...
2017-12-08 13:34:33 17672 1 Status: Connection established, initializing TLS...
2017-12-08 13:34:33 17672 1 Status: Verifying certificate...
2017-12-08 13:35:06 17672 1 Status: TLS connection established, waiting for welcome message...
2017-12-08 13:35:06 17672 1 Response: 220-Microsoft FTP Service
2017-12-08 13:35:06 17672 1 Status: Invalid character sequence received, disabling UTF-8. Select UTF-8 option in site manager to force UTF-8.
2017-12-08 13:35:06 17672 1 Response:     Warning: This IT system is restricted to company authorised users only, including authorised third parties. Unauthorised access or use is a violation of Company’s policies and potentially the law. 
2017-12-08 13:35:06 17672 1 Response:     
2017-12-08 13:35:06 17672 1 Response: 220 Our IT systems may be monitored for administrative and security reasons. By proceeding, you acknowledge that you have read and understood this notice and that you consent to the monitoring. [ftps0]
2017-12-08 13:35:06 17672 1 Command: USER ftp_usr_comp_ext
2017-12-08 13:35:06 17672 1 Response: 331 Password required
2017-12-08 13:35:06 17672 1 Command: PASS ****************
2017-12-08 13:35:06 17672 1 Response: 230 User logged in.
2017-12-08 13:35:06 17672 1 Command: SYST
2017-12-08 13:35:06 17672 1 Response: 215 Windows_NT
2017-12-08 13:35:06 17672 1 Command: FEAT
2017-12-08 13:35:06 17672 1 Response: 211-Extended features supported:
2017-12-08 13:35:06 17672 1 Response:  LANG EN*
2017-12-08 13:35:06 17672 1 Response:  UTF8
2017-12-08 13:35:06 17672 1 Response:  AUTH TLS;TLS-C;SSL;TLS-P;
2017-12-08 13:35:06 17672 1 Response:  PBSZ
2017-12-08 13:35:06 17672 1 Response:  PROT C;P;
2017-12-08 13:35:06 17672 1 Response:  CCC
2017-12-08 13:35:06 17672 1 Response:  HOST
2017-12-08 13:35:06 17672 1 Response:  SIZE
2017-12-08 13:35:06 17672 1 Response:  MDTM
2017-12-08 13:35:06 17672 1 Response:  REST STREAM
2017-12-08 13:35:06 17672 1 Response: 211 END
2017-12-08 13:35:06 17672 1 Command: PBSZ 0
2017-12-08 13:35:07 17672 1 Response: 200 PBSZ command successful.
2017-12-08 13:35:07 17672 1 Command: PROT P
2017-12-08 13:35:07 17672 1 Response: 200 PROT command successful.
2017-12-08 13:35:07 17672 1 Status: Logged in
2017-12-08 13:35:07 17672 1 Status: Retrieving directory listing of "/Prod/Outbound"...
2017-12-08 13:35:07 17672 1 Command: CWD /Prod/Outbound
2017-12-08 13:35:07 17672 1 Response: 250 CWD command successful.

Stack Trace:

   at FluentFTP.FtpSocketStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at FluentFTP.FtpSocketStream.ReadLine(Encoding encoding)
   at FluentFTP.FtpClient.GetReply()
   at FluentFTP.FtpClient.Handshake()
   at FluentFTP.FtpClient.Connect()
   at ASOSSFTP.DownloadFile.DownloadFileFromFTP()

Answer 1

In FileZilla, you are connecting to implicit FTPS port 990.

If you also use this port in C#, you cannot use FtpEncryptionMode.Explicit .

Use FtpEncryptionMode.Implicit .

Though you better connect to port 21 and keep using FtpEncryptionMode.Explicit , if that port is available.

Answer 2

The following code is all you need to get FluentFtp (at least nuget (1.0.5824.34026) to use secure connection .

        FtpClient fclient = new FtpClient(hostname, username, password); // or set Host & Credentials

        fclient.EncryptionMode = FtpEncryptionMode.Implicit;  
        fclient.SslProtocols = SslProtocols.Tls12;

        //client.Port = 990;  // Not required - probably gives you exceptions if you try to set it. 

        fclient.Connect();
        fclient.UploadFile(@"C:\tmp\a.txt", "big.txt");