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I'm having this issue on my Windows 7 machine where a call to MulticastSocket.receive() in Java will hang indefinitely (it never receives the packets) when I try to listen in on a server connected to a non-192.168.X.X network. Provided that the server is connected on the 192.168.X.X network, MulticastSocket.receive() will not hang. I'm fairly sure that this is a configuration issue on my Windows 7 machine, as it works on the other development systems at my workplace running Windows XP and Ubuntu 10.04.

Any help would be appreciated.

Update:

I figured out why MulticastSocket.receive() was hanging indefinitely. What happened was that Windows Firewall was blocking the incoming packets from the network corresponding to my server. A quick fix to this problem was to disable Windows Firewall on that network (in my case, I disabled Windows Firewall on my Public Network). After that, the MulticastSocket.receive() was able to get the incoming packets.

Justin
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1 Answers1

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"non-192.168.X.X network" implies that the listening machine is on a 192.168.X.X network. If that's the case, then it's probably a situation where multicast traffic is not being routed between the networks (it usually isn't). Are the other development machines that you mention on the same network as the Windows 7 machine? Or are they dual-homed (attached to two network segments)?

You can see if your network admins can configure their routers to pass this traffic.

parsifal
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  • Yes, that is correct. My listening machine is on the 192.168.X.X network. As for the admin of the network I want to connect to, I am the admin, since it's a private network shared between myself and my coworker for development purposes. I'm just not sure how to route the traffic to my machine. It seems to work on my coworker's development systems, which I've referenced above. – Justin Mar 02 '13 at 01:12
  • As a result, I think the issue has something to do with the configuration of my own PC, rather than the network itself. – Justin Mar 02 '13 at 15:09
  • Are you saying that your co-worker's machine can receive broadcast messages when it is on a non-192.168.x.x. network? – Darius X. Mar 04 '13 at 13:01
  • @Darius: Yes. My coworker's machine can receive broadcast messages when it is on a non 192.168.x.x network. – Justin Mar 04 '13 at 13:16
  • @Parsifal: Okay. It seems that I was able to get MulticastSocket.receive() working. Your answer was the closest. What seemed to be happening was that Windows Firewall was blocking the packets. As a result, MulticastSocket.receive() would just hang there, waiting for an incoming packet that would never come. A really short fix to this was to disable Windows Firewall on the network corresponding to the server (in this case, I disabled Windows Firewall on my Public Network). – Justin Mar 04 '13 at 14:38