I don't know anything about DVB data transmission. But your description makes perfect sense for Ethernet, for example. Each station only receives messages which are addressed to its MAC address, or sent to the broadcast address. If you want to listen to all traffic, you use promiscuous mode. It doesn't matter what the IP address is; the MAC function will discard any packets without the correct MAC address before the IP address is checked. So packets with your IP address sent to the wrong MAC address are not useful. I think you need to either correctly set the MAC address for each packet you are sending (based on the IP address to which its sending, eg through ARP) or send all packets to the broadcast address. Hamish