title: Why does mDNS (Bonjour, Avahi, etc) use UDP?
body: <p>It seems to me that a lot of the problems with DNS, particularly security problems, have the root cause of DNS being implemented over UDP; for example the responder doesn't have to be who he says he is.</p>
  
  <p>I don't know the details of mDNS protocol (which I assume is much newer than DNS), maybe it takes care of these problems in its application level.  Can anyone shed some light on this for me?</p>