ISPs can still get /24 of IPv4 today for free even after it "ran out". This comes from space that was set aside before runout. https://www.arin.net/participate/policy/nrpm/#4-10-dedicated...
replyThis IPv4x thing is bullshit but we should be accurate about how it would play out.
So under this IPv4x proposal one gets an IPv4 /24, and receives a whole bunch of extended address space 'for free'.
replyBut right now you can get an IPv4 /24 (as you say), but you can get an IPv6 allocation 'for free' as we speak.
In both cases legacy code cannot use the new address space; you have to:
* update the IP stack (like with IPv6)
* tell applications about new DNS records (like IPv6)
* set up translation layers for legacy-only code to reach extended-only destination (like IPv6 with DNS64/NAT64, CLAT, etc)
You're updating the exact same code paths in both the IPv4x and IPv6 scenarios: dual-stack, DNS, socket address structures, dealing with legacy-only code that is never touched to deal with the larger address space.