[Dylan16807]

So I'm not saying it's backwards compatible, exactly, but what would you call 64:ff9b::?

[mulmen]

A reserved gateway address space?

https://en.m.wikipedia.org/wiki/NAT64

[Dylan16807]

By embedding the IPv4 address space inside the IPv6 address space.

They are different protocols but they are not disjoint address spaces.

You add 96 bits to the address and boom it's converted.