Good morning all, I have a program that receives and sends UDP broadcasts. I am testing on two Vista computers hooked up to an ethernet hub. I set Laptop A to listen for a UDP broadcast, then have Laptop B broadcast a message. A successfully receives and prints the message. But when I switch the roles and have A broadcasting and B listening, B doesn't receive anything. Firewalls are all off. And also, TCP communication works both ways on the two computers; it's just the UDP that chokes. The computers can ping each other just fine, too. Any idea what I might be doing wrong here?

Aha! The laptop that didn't receive the message doesn't have internet access, and the other one does! So when the internet-connected laptop was broadcasting, it sent the broadcast to my wireless internet, not my LAN. When I disabled the internet, the UDP transmission worked on both laptops.

So, problem solved.

But, is there anyway to specify which network I broadcast to? It would be nice if I didn't have to keep switching off the internet to play the game I'm writing. Thanks!

Thanks again, hplus. I really appreciate your help!