On 18/9/2013 18:31, Dennis Lee Bieber wrote: > On Tue, 17 Sep 2013 18:34:50 -0400, William Ray Wing <w...@mac.com> > declaimed the following: > > >> >>I think you need to read up on some of the most basic fundamentals of tcp/ip >>networking, i.e., the basis of the global internet. EVERY network packet >>(and I do mean every) packet in an IP network carries both a source and a >>destination address in its header. These are fundamentally necessary in >>order to allow the gateway router at the originating site to direct an >>outgoing packet to its destination, and allow the receiving host at the >>destination site to craft reply packets. >> > > Even worse -- IP packets are wrapped by Ethernet packets which use MAC > addresses for direct routing between nodes... Granted, those MAC addresses > may not propagate beyond the next defined gateway IP host, but they do > (theoretically) identify the exact NIC that sent the packet.
Noting reliable about the MAC adress. Many systems permit or even encourage spoofing. And it gets overwritten at each hop, so the other end cannot easily determine the number a client may have made up. The first time I added a router to my cable modem, I had to tell it to use (spoof) the old MAC address so that the cable modem didn't have to be reprogrammed. -- DaveA -- https://mail.python.org/mailman/listinfo/python-list
