MulticastSocket simply hangs on receive()

[Dan Bizman]

I wrote a very simple app to send/receieve from multicast sockets. It starts up fine and claims it has sent a message (the sender) but the receiver never comes out of receive. It just hangs forever, never printing a message. Any idea what's wrong?

Here's what I'm doing:

1. The receiver joins group "225.9.9.9:9045" and sits there listening
2. The sender joins group "234.6.6.6:4590" but sends a message to "225.9.9.9:9045," i.e. the receiver group.

What am i doing wrong?

[Ernest Friedman-Hill]

Moving to "Sockets and Internet Protocols."

[Dan Bizman]

In case anyone's wondering, I figured this out. I had been told to install the "Windows Loopback Adapter" from Micorosft, so the laptop would act as though it were connected to a network, thus allowing multicasting. This does NOT work. I got nothing. On a whim, I attached an ethernet card that was not connected to anything -- it had no cable connected and it's not wireless. I also disabled Windows Looback Adapter. And it worked! All the laptop needs is an ethernet card; it doesn't need to be connected to anything. Weird.