>I thought about putting the laptop's MAC address in the packet, and >using mac-source, but I've it seems to MAC address is stripped out over >the internet. I think you misunderstand how the mac address is used. Your data is broken into chunks and wrapped with TCP headers containing port numbers, these chunks are wrapped in IP headers containing IP addrs. Those chunks of data are wrapped in ethernet headers containing MAC addrs. The ethernet headers are only valid on the current LAN segment or collision domain. As soon as the ethernet wrapped "frame" is received at some device that speaks ethernet (like a gateway router), the ethernet headers (wrapper) are removed and discarded. The IP wrapped data will be RE-WRAPPED in ethernet headers valid for the segment on the other side of the router. This continues until the data reaches the destination. There is no way to preserve the MAC address when the destination is not in the same collision domain unless you want to invent your own tunneling protocol.
