Hackaday

An alternate history thought experiment imagines what would have happened if IPv6 had been rejected in favor of a backward-compatible protocol called IPv4x. The concept would have extended IPv4 addresses with a 96-bit sub-address block, giving each IPv4 address owner a 128-bit address space while remaining compatible with existing IPv4-only equipment. DNS and DHCP would have been updated to support both address types, and NAT would have been unnecessary. In reality, IPv6 adoption has been slow and painful, and the author behind the IPv4x concept has proposed a gateway allowing IPv6 hosts to be accessible from IPv4-only networks.

The IPV4 We Didn’t Get