title: java.io.IOException: No route to host using MulticastSocket on MacOS X Snow Leopard
body: <p>I have a java application using multicast in order to advertise some entity - all worked fine when I tried the application a couple of weeks back. However, this is not the case anymore: I'm getting a</p>
  
  <pre><code>java.io.IOException: No route to host
  </code></pre>
  
  <p>exception when the unchanged application is started again. The application is sending DatagramPackets to 224.0.0.1.</p>
  
  <p>My current system is Mac OS X Snow Leopard (10.6.7) with Java 1.6.0_24 installed.</p>
  
  <p>I've tried out several approaches with the following outcomes:
   - search google -> some suggestions, none of which helped so far
   - disable firewall -> not successful
   - disable network interface (to force it to use the loopback) -> not successful
   - running it on Win machine -> successful, so I assume it definitely has something to do with the current (or changed/updated) system configuration</p>
  
  <p>Any pointers or suggestions are greatly appreciated!</p>
  
  <p>Cheers</p>