It's already a bit like that, but they can and do disable it. You can see the other comments in this thread: many people disable IPv6 upon any sign of a networking problem.
It's already a bit like that, but they can and do disable it. You can see the other comments in this thread: many people disable IPv6 upon any sign of a networking problem.
Once v6 has reached enough adoption, you can turn off v4. Those who want to keep the addrs from v4 can, except now they get way more addresses under those too. Others can start building a clean new topology under the other prefixes without worrying about compatibility.
To me it looks like something that would have gained nearly no actual adoption outside some toy examples. Later you will need to anyway get new DNS, DHCP(or alternative) and so on.
Today's DNS6 DHCP6 etc are totally incompatible with v4. 4:: buys backwards-compatibility. Each can be updated to support longer addrs without caring whether you use it with v4 or v6.