Comment by UltraSane

5 days ago

At first I though so too but IPv6 is actually easier. instead of CIDR you always have 64 bits for network and 64 for host. You get a public /48 IPv6 prefix that allows for 16 bits of subnets and then the host addresses can just start at 1 if you really want. So addresses can be prefix_1_1 if you want. And the prefix is easy to memorize since it never changes.

I DO think using 64 bits for hosts was stupid but oh well.

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UltraSane

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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?

  • 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.