That seems oddly rigid though. I need to known in advance which networks will definitely never need subnetting so I can assign them a /64.
Why have so, so many address bits and then give us so few for subnetting? People shame ISPs endlessly for only giving out /56s instead of /48s, pointing at the RFCs and such. But we still have 64 entire bits left over there on the right! For what? SLAAC? Was DHCP being stateful really such a huge problem that it deserves sacrificing half of our address bits?
The actual intention has always been that there be no hard-
coded boundaries within addresses, and that Classless Inter-
Domain Routing (CIDR) continues to apply to all bits of the
routing prefixes.
Why have so, so many address bits and then give us so few for subnetting? People shame ISPs endlessly for only giving out /56s instead of /48s, pointing at the RFCs and such. But we still have 64 entire bits left over there on the right! For what? SLAAC? Was DHCP being stateful really such a huge problem that it deserves sacrificing half of our address bits?