Robert GrahamWhat's a MAC address and Ethernet frame header for? Why don't packets simply start with an IP header?
Mrs Mouse at work@ErrataRob because not all of the traffic on the wire is IP.
@ErrataRob fun fact, the first versions of IP had a 8 bit network and 24 bit host with the design of using the mac address as the host part of the IP address.
then 48 bit macs spoiled it.
well, also giving a class a to every site also wasn't going to pan out.
Of course, this was before classful networks.
Patrick $8 
@ErrataRob what if DHCP was non-negotiable. You plug in and get an IP whether you like it or not
radioactivecat@phurd @ErrataRob It puts the IP on the interface *or it gets the hose again*!