title: Connection loses on data-send. Server receives RST, ACK after handshake
body: <p>I've got a simple TCP-server hosted on 64bit windows server 2008 r2. TCP-server just receives connection and replies to incoming data with recieved message(echo). There are about 600-700 clients who try connect and send some information. And the problem is: server loses almost all of connections(about 90%) when data is sended from client to server(First 15-20 connections have been performed normallly). I've sniffed the TCP-traffic with Whireshark. 
  From server side log is:</p>
  
  <pre><code> +--------------+--------------+--------------------------------+
   | Source       | Destination  | Info                           |
   +--------------+--------------+--------------------------------+
   | 1. client ip | server ip    | [SYN] **Handshake step1**      |
   | 2. server ip | client ip    | [SYN, ACK] **Handshake step2** |
   | 3. client ip | server ip    | [ACK] **Handshake step3**      |
   | 4. client ip | server ip    | [RST, ACK] **Loses connection**|
   +--------------+--------------+--------------------------------+
  </code></pre>
  
  <p>From client side log is:</p>
  
  <pre><code> +--------------+--------------+--------------------------------+
   | Source       | Destination  | Info                           |
   +--------------+--------------+--------------------------------+
   | 1. client ip | server ip    | [SYN] **Handshake step1**      |
   | 2. server ip | client ip    | [SYN, ACK] **Handshake step2** |
   | 3. client ip | server ip    | [ACK] **Handshake step3**      |
   | 4. client ip | server ip    | [PSH, ACK] Message             |
   | 5. client ip | server ip    | [PSH, ACK] CRLF message        |
   | 6. server ip | client ip    | [RST, ACK] **Loses connection**|
   +--------------+--------------+--------------------------------+
  </code></pre>
  
  <p>In both cases the «Reset cause» is: \000\000\000......\000
  The connection did not lose when we're connecting from local network. </p>