No such host is known socket connection

c#, exception, sockets, telnet

Solution

The solution was something quite easy and overlooked. First I noticed that the tcpclient prefers an ip address and not a name. Then I also realized that sometimes there were extra spaces on either side of the domain name. So I used the below code to strip the characters and change it to an ip.

string.Trim();
//Telnet Start
IPHostEntry hostInfo = Dns.Resolve(hostnamehere);

Problem

I'm trying to work with this library for telnet connections. I have called the function correctly and it executes the code below but fails giving the following error: ``` System.Net.Sockets.SocketException was unhandled HResult=-2147467259 Message=No such host is known Source=System ErrorCode=11001 NativeErrorCode=11001 StackTrace: at System.Net.Sockets.TcpClient..ctor(String hostname, Int32 port) at MinimalisticTelnet.TelnetConnection..ctor(String Hostname, Int32 Port) in c:\users\kylec\documents\visual studio 2010\Projects\Mail Server Capture\Mail Server Capture\TelnetInterface.cs:line 36 at Mail_Server_Capture.Form1.btn_MailGet_Click(Object sender, EventArgs e) in c:\users\kylec\documents\visual studio 2010\Projects\Mail Server Capture\Mail Server Capture\Form1.cs:line 55 at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(Form mainForm) at Mail_Server_Capture.Program.Main() in c:\users\kylec\documents\visual studio 2010\Projects\Mail Server Capture\Mail Server Capture\Program.cs:line 18 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: ``` Code: ``` public TelnetConnection(string Hostname, int Port) { tcpSocket = new TcpClient(Hostname, Port); } ``` I have searched here looking for this problem and it seems pretty common. Some people are saying the host truly is unreachable (this is not the case), its a Microsoft .NET problem or its just an exception that can be ignored. I can't seem to get the program to pass it though if it is something that can be ignored. I also can't seem to find any solutions as to fixing it. I'm pretty lost on this one, any help would be appreciated.

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