On 11/12/24 13:28, James Knott wrote:
On 11/12/24 15:24, Lew Wolfgang wrote:
Exactly. Why carry around all those extra host bits if they'll never be used. 24 makes sense to include MAC addresses, maybe round up to 32 in an abundance of caution. But 64? Wouldn't 4.3 billion host address be sufficient with /32?
A MAC address is 48 bits, so it has to be at least that big, as was the case with Netware. As I mentioned, 64 was likely selected as it cut the address in half. Also, with modern networks, moving bits around is trivial. One other aspect is the sparely populated, huge address space makes it extremely difficult to find something to attack, unlike with IPv4, where most addresses are occupied.
Of course you're correct! 48-bits in a MAC address. That makes a bit more sense. After all, /64 is a nice power of two. It's amazing, Ethernet addressing was developed in 1973. How prescient was Bob Metcalfe and his team to settle on 48-bit addressing! It's funny what one remembers. I recall sitting on the toilet at work in 1976 reading a EDN magazine article talking about how packet switched networks were the wave of the future. It was ten years later when I found myself pulling that yellow Thicknet coax around to set up our first Ethernet subnet. Now look at what we have! Regards, Lew