java.io.IOException: No route to host using MulticastSocket on MacOS X Snow Leopard

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

java.io.IOException: No route to host

exception when the unchanged application is started again. The application is sending DatagramPackets to 224.0.0.1.

My current system is Mac OS X Snow Leopard (10.6.7) with Java 1.6.0_24 installed.

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

Any pointers or suggestions are greatly appreciat开发者_JAVA百科ed!

Cheers

No route to host is caused by your process receiving an ICMP "host unreachable" message from some router on the path between you and the destination IP. Since you're getting this on a multicast address, I'd suspect something wrong with your router configuration.