title: Detect if Router supports Multicast
body: <p>Is there a way to programmatically detect if a router supports multicast? Either in plain <code>C</code> (BSD sockets) or preferably in some higher level fashion on OSX (<code>Objective-C</code>/<code>Cocoa</code>).</p>
  
  <p>Update: I'm assuming here, that we have only one process running to determine the multicast support (so approaches suggesting multiple clients on separate machines are not relevant here).</p>