No connection could be made because the target machine actively refused it

No connection could be made because the target machine actively refused it

• mark baran

  The buffer size was actually 32 bytes. Is it too small for this purpose
  
  Thanks.
  
  

• Fabio Miguez

  Thanks a lot.
  
  I just ordered a Windows Server TCP/IP Reference book you've mentioned and a host of others at Amazon.com.
  
  No matter how many books we read we will keep asking stupid questions though.
  
  
  
  

• Xin Jin

  The buffer can be of any size.. Since you were waiting in the loop till you get the whole byteBuffer.Length,  you will block if the other end is sending data less than byteBuffer.Length and has not closed the socket (On a socket closure receive will return 0 bytes)
  
  
  while (totalBytesRcvd < byteBuffer.Length)
    { if ((bytesRcvd = sock.Receive(byteBuffer, totalBytesRcvd,
         byteBuffer.Length - totalBytesRcvd, SocketFlags.None)) == 0)
         {Console.WriteLine("Connection closed prematurely.");
          break;
    }
    totalBytesRcvd += bytesRcvd;
  }
  

• FastLiveHelp

  What is the size of the buffer you are reading the data into   If the size of the buffer is larger than the size of the data that the server is going to send, then the receive call will block once it has read all of the data the server is sending. 
  
  In other words:  If you buffer is 128 bytes long and the server is only sending 124 bytes, then you will read the 124 bytes from the server and then issue another Receive call waiting for the remaining 4 bytes that you think the server is going to send (which the server will never send).  This could result in an apparent hang due to the fact that the client and server aren't in agreement of how much data is being transmitted.  You could try setting the ReceiveTimeout on the client socket.
  
  In V2.0 there is a ReceiveTimeout property.  In previous versions you can call
  
  

  socket.SetSocketOption(SocketOptionLevel.Socket,                                   SocketOptionName.ReceiveTimeout, timeoutValue);

  
  
  

• mydarlingdarla

  
  HI Guys
  
  It's very easy. please first understand, what will to do try. u try send a byte of data server to Client cliet to Server. So those two type of work, whether one is Do the Job as the receiver. So
  
  We must Start that Receiver , rather than start the Sender.
  
  if u confuse.
  
  Please start Server first,
  
  after start Client Do
  
  it's work.
  
  tnx Guys.,
  
  
  
  

• Wazoo

  Thanks, this is great. I had vaguely those considerations in mind. You've opened the road for me now. I will implement it.
  
  

• Patrick Verleysen

  It should work... 
  
  1. The receive is a blocking call. Is the other end sending...
  
  2. Did you initialize totalBytesRcvd to 0
  
  
  

• BubbaHasty

  Answering your second question (and I appreciate both) - yes it was initialized o 0.
  
  I can answer the first question with 85% certainty only. A system process Winnt\system32\MStask.exe was attached to this port and I realized a few minutes after I posted this that probably the other side was either not sending anything or the process was attached to this port as a perfunctory measure for some unknown contingencies.
  
  Those dynamic considerations escape newbies, as you know. It takes time.
  
  I will make sure there is a full duplex communication via a port next time.
  
  Thanks.
  
  

• thatKid

  This means that there is no TCP Port *LISTENING* for requests at the port 3380
  you mentioned. It could also mean that there is a firewall of some sorts that is
  not allowing incoming connections on that port eventhough you might have a server listening on that port
  
  

• 2drunk2funk

  You were right. When I chose a post where a server was listening a connection was made right away, however,
  
  

  while (totalBytesRcvd < byteBuffer.Length)
    { if ((bytesRcvd = sock.Receive(byteBuffer, totalBytesRcvd,
         byteBuffer.Length - totalBytesRcvd, SocketFlags.None)) == 0)
         {Console.WriteLine("Connection closed prematurely.");
          break;
    }
    totalBytesRcvd += bytesRcvd;
  }

  At the IF statement the program stopped responding (in debug) for unknown reason and without giving me any identifyable error message or demand for Console input. 11 bytes were sent to the server. Any insight please

  
  
  
• No connection could be made because the target machine actively refused it