| > There was a time when the designers believed that you'd use your 48 bit MAC address as part of this. Now we know that's a PII nightmare and nobody does it. Nobody includes their MAC address in their public IPv6 addresses anymore, but every IPv6 setup that I've seen still gives every device a unique globally-routable IPv6 address, with no NAT at all. > One of my favorite is the decision to default to /64 blocks. The nice thing is that a /64 is big enough that clients can just randomly pick any address, and it will almost certainly be available, meaning that you don't need DHCP. This is actually widely implemented, and is known as SLAAC [0]. > Yet we're still stuck with the 128 bit addresses that came from that. The extra address space only adds 16 bytes to every packet, and it ensures that we will never run out of addresses like we did with IPv4. [0]: https://en.wikipedia.org/wiki/IPv6#Stateless_address_autocon... |
Crucially though, if we change it, we just have to change how addresses are allocated, not change the protocol again.