Say I have the ip and mac address of a computer inside a network and I wish to send him a UDP message. By initializing the mac and ip addresses of the sent message to the given, when the network router recives the message he should pass it to the computer with the same mac address...right?

Im asking becuase a program I write dosent seem to handle this limitation. it works great when its on the same network, but otherwise ...nada.

Thanks