Background Workers with Asynch TCP Connections [modified]

[Chinners]

Hi, I am trying to use remoting for an application I am writing. One problem with remoting is the timeout is too high if a particular IP address is not found (i.e. the remote machine is not turned on). I also need to check that the remote listener is alive. My solution to this was to write a small routine that "Pings" the remote object beforehand to see if it was alive. This "Ping" routine uses a s simple async TCP connection, so I can adjust the timeout: Private HasResponded As Boolean Private Timeout As Integer = 100 Private Sub TCPResponded(ByVal ar As System.IAsyncResult) HasResponded = True End Sub Public Function IsAlive(ByVal IPAddress As String) As Boolean Dim Conn As New AsyncCallback(AddressOf TCPResponded) Dim Tcp As New System.Net.Sockets.TcpClient() Dim MyTimeOut As Integer = Timeout HasResponded = False Tcp.BeginConnect(IPAddress, 9000, Conn, Nothing) While HasResponded = False And MyTimeOut > 0 System.Threading.Thread.Sleep(10) MyTimeOut -= 1 End While If Tcp.Connected Then Tcp.Close() Return True Else Tcp.Close() Return False End If End Function This class works fine when in the UI thread - it can tell me if a machine is alive or not within a second (I am only dealing with local ethernet, so one second is considered slow). However, in my UI, I would like an icon to display the status of the remote machine. I thought I could write a simple background worker to call the above code. However, on the TCP.BeginConnect, I get the following error: System.Net.Sockets.SocketException was unhandled by user code ErrorCode=10045 Message="The attempted operation is not supported for the type of object referenced" Source="System" StackTrace: at System.Net.Sockets.Socket.DoMultipleAddressConnectCallback(Object result, MultipleAddressConnectAsyncResult context) at System.Net.Sockets.Socket.BeginConnect(String host, Int32 port, AsyncCallback requestCallback, Object state) at System.Net.Sockets.TcpClient.BeginConnect(String host, Int32 port, AsyncCallback requestCallback, Object state) Has anyone tried an Async connect within a background worker before, and got it working? I have tried googling this, but cant find anything that looks vaguely similar to my problem. As of yesterday, I h