Comment by muvlon

5 days ago

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?

1 comment

muvlon

viraptor 5 days ago

> That seems oddly rigid though.

We're past that for a decade, but various services have not caught up yet https://datatracker.ietf.org/doc/html/rfc6177

         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.