title: Is Winsock error 10054 (WSAECONNRESET) "normal" with UDP to/from localhost?
body: <p>"What could possibly go wrong with using UDP for inter-process communications on a single Windows PC?" I thought... and proceeded to implement it.</p>
  
  <p>But despite sending mere hundreds of bytes and only very sporadically, and also despite UDP being used as a connectionless protocol (<code>sendto()</code> function employed), I am plagued by random occurrences of error 10054 - "connection reset". I find this very confusing. Is it:</p>
  
  <ul>
  <li>perfectly normal, to be expected, in which case... what does it mean has happened?</li>
  <li>completely unexpected, and I've probably implemented something wrong</li>
  <li>completely unexpected, so I should check for conflicting software (e.g. for <a href="https://support.microsoft.com/en-us/kb/981344" rel="noreferrer">problems like this</a>)</li>
  <li>something else?</li>
  </ul>
  
  <p>I read somewhere that it could indicate that there is no receiving port open at the other end... but this makes even less sense to me - isn't UDP simply supposed to send the datagram off and not care what happens to it? Or is there some special case when the send occurs to/from ports on the same machine (localhost)?</p>