Unknown command FEAT when accessing FTP server

Question

I just created an FTP server based on the code provided here http://www.codeguru.com/csharp/csharp/cs_network/sockets/article.php/c7409/A-C-FTP-Server.htm . Then I installed Nuget packages for FtpClient, so that I can create a test FTP client which connects to FTP server. Following is my code:

[TestMethod]
    async public Task TestMethod1() // wanted to make it async as I may connect have something related to database in future
    {
        var client = new FtpClient
        {
            Host = "127.0.0.1",
            Port = 21,
            Credentials = new NetworkCredential
            {
                UserName = "123",
                Password = "123",
            },
            DataConnectionType = FtpDataConnectionType.PASV // If I don't add this, I get EPSV unknown command
        };

        await client.ConnectAsync();
        Debug.WriteLine("Connected");

        client.SetWorkingDirectory(@"C:\Users\myname\Desktop");
        Debug.WriteLine(client.GetWorkingDirectory());

        try
        {
            var items = client.GetListing(); // Exception shows up here.
            Debug.WriteLine(items.Count());
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex.Message);
        }
}

The issue could be that I don't have a command handler for FEAT in my server. But, my FTP server runs completely fine with filezilla. If command handler is required, can someone provide me code for this?

If I ignore this error, I get this exception in test method "Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host."

Any ideas?

[EDIT] Here's the full exception:

Test method Blackhawk.Core.FtpServer.Test.UnitTest1.TestMethod1 threw exception: 
System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. --->        System.Net.Sockets.SocketException: An existing connection was forcibly closed   by the remote host
    at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
   at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
 --- End of inner exception stack trace ---
     at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
   at    System.Net.FtpClient.FtpSocketStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.Net.FtpClient.FtpSocketStream.ReadLine(Encoding encoding)
   at System.Net.FtpClient.FtpClient.GetReply()
   at System.Net.FtpClient.FtpClient.Execute(String command)
   at System.Net.FtpClient.FtpClient.OpenPassiveDataStream(FtpDataConnectionType type, String command, Int64 restart)
   at System.Net.FtpClient.FtpClient.OpenDataStream(String command, Int64 restart)
   at System.Net.FtpClient.FtpClient.GetListing(String path, FtpListOption options)
   at System.Net.FtpClient.FtpClient.GetListing(String path)
   at Blackhawk.Core.FtpServer.Test.UnitTest1.<TestMethod1>d__2.MoveNext() in UnitTest1.cs: line 44
 --- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()

What "Nuget packages for FtpClient"? This one? https://www.nuget.org/packages/System.Net.FtpClient/ Can you include an exact exception message and its callstack? Can you enable tracing (see `FtpTrace`) and include the trace file into your question? — Martin Prikryl, May 27 '15 at 07:22
So you just see the "Unknown command FEAT" message somewhere in the log, right? You do not really get the error. The message is completely irrelevant to your problem. — Martin Prikryl, May 28 '15 at 04:50
The message "Unknown command FEAT" is still there because I don't have a command handler for that in my FTP server. My question was (if you read it carefully....the whole question... it's in English language), that whether the exception is because of unavailability of command handler for FEAT or for some other reason. If it's because of command handler, provide me the code. Otherwise, how can I solve the issue if I ignore the "Unknown command FEAT" message. So, if you understand this whole thing (and I hope you do!!), my answer fixes the problem by ignoring this message. Jesus... — sanmis, May 28 '15 at 10:21

score 1 · Accepted Answer · answered May 28 '15 at 00:50

I was able to solve the problem by changing data connection type to AutoActive. Here's the final code which works:

[TestMethod]
    async public Task FtpTestUser1()
    {
        var client = new FtpClient
        {
            Host = "127.0.0.1",
            Port = 21,
            Encoding = System.Text.Encoding.Default,
            Credentials = new NetworkCredential
            {
                // Storing username, password and default directory in a .dat file
                UserName = "123", 
                Password = "123",
            },
            DataConnectionType = FtpDataConnectionType.AutoActive // Changed this part.
        };

        await client.ConnectAsync();
        Debug.WriteLine("Connected");

        var path = @"Test"; // This path is now relative to the default directory

        client.SetWorkingDirectory(path);
        Debug.WriteLine(client.GetWorkingDirectory());


        var items = client.GetListing();
        Assert.IsTrue(items.Any());
        Debug.WriteLine(items.Count());

        foreach (var ftpListItem in items)
        {
            Debug.WriteLine(string.Format("File name is {0}", ftpListItem.Name));
        }        
    }

Unknown command FEAT when accessing FTP server

1 Answers1