C# socket exception "an existing connection was forcibly closed by the remote host"

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C#3.5

I am trying to write a small server client code where the client sends a control message to the server to execute a job.

The program flow goes as such

1. client sends a control message and goes into wait till a return message is received.
2. server receives the message and sends an execution "success/failure" message to the client and busy waits till a shutdown(i.e. zero byte) message is received.
3. client receives the "success/failure" and sends a close socket message (zero byte shutdown.send) to server and goes into busy wait till it receives a shutdown message.
4. server receives the shutdown messages, sends a shutdown in return and releases the resources of the socket.
5. client receives the shutdown and releases the resources of the socket.

What I have tried:

the code is as follows
client side

try
            {
                sock = new Socket(ipAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
                sock.Connect(remoteEP);

                string sent_msg = "RESTART CCMCOM";
                MessageLogTextBox.AppendText("Message sent at " + DateTime.Now + " : " + sent_msg + Environment.NewLine);
                byte[] msg = Encoding.ASCII.GetBytes(sent_msg);
                sock.Send(msg);
                
                Thread.Sleep(500);

                msg = new byte[1024];
                sock.Receive(msg);
                string received_msg = Encoding.ASCII.GetString(msg).Trim();
                MessageLogTextBox.AppendText("Message received at " + DateTime.Now + " : " + received_msg + Environment.NewLine);

                MessageLogTextBox.AppendText(Environment.NewLine);
                MessageLogTextBox.AppendText(Environment.NewLine);


                sock.Shutdown(SocketShutdown.Send);
                while (sock.Receive(msg) != 0) ;
                sock.Disconnect(false);
                sock.Close(); 
            }
            catch (Exception ex)
            {
                MessageLogTextBox.AppendText(ex.Message);
            }

server side

try
            {
                listener.Bind(localEndPoint);
                listener.Listen(10);
                outputFile.WriteLine("DCA1_CCMCOM_Remote_Restart_Service started at : {0}", DateTime.Now);

                // Start listening for connections.  
                while (true)
                {
                    //Thread is suspended while waiting for an incoming connection.  
                    handler = listener.Accept();

                    string data = null;

                    // An incoming connection is processed.                 
                    bytes = new byte[1024];
                    int bytesRec = handler.Receive(bytes);

                    if (bytesRec != 0)
                    {
                        data = Encoding.ASCII.GetString(bytes, 0, bytesRec);

                        if (data.IndexOf("RESTART CCMCOM") > -1)
                        {
                            //search the desired service
                            ServiceController sc = new ServiceController("DCA1_CCMCOM");

                            //if the service is running, stop it
                            if (sc != null && sc.Status.Equals(ServiceControllerStatus.Running))
                                sc.Stop();

                            Thread.Sleep(10);
                            sc.Refresh();

                            //busy wait till it is stopped
                            while (sc != null && !sc.Status.Equals(ServiceControllerStatus.Stopped))
                                sc.Refresh();

                            sc.Start();
                            outputFile.WriteLine("Service restarted at  : {0}", DateTime.Now);
                            handler.Send(Encoding.ASCII.GetBytes("Service Restarted"));

                            //Expecting a close request from client end, busy wait till a zero byte (i.e. close) request is received
                            while ( handler.Receive(bytes) != 0) ;
                            //after receiving the close request, send a return shutdown request to client
                            handler.Shutdown(SocketShutdown.Send);
                            handler.Disconnect(true);
                            handler.Close();
                        }
                    }
                    else
                    {
                        handler.Shutdown(SocketShutdown.Send);
                        handler.Disconnect(true);
                        handler.Close();
                    }
                }
            }
            catch (Exception e)
            {
                outputFile.WriteLine("DCA1_CCMCOM_Remote_Restart_Service stopped at : {0} due to {1}", DateTime.Now, e.Message);
                handler.Shutdown(SocketShutdown.Both);
                handler.Disconnect(true);
                handler.Close();
            }

where am i going wrong?