alt Hacker NewsIPv4-compatible v6 address was only for dual-stack hosts talking over a v4 network. They still had their own v6-native addresses that they had to use if they wanted a v6 network. So this isn't what I described where the v6-native route is the same as the v4 route, or a superset in the later stages (shared down to /32, v6-only in deeper subnets).
The thing I want to solve isn't just v4 routers in the middle, that's more of a bonus. All the routers between my machine and any service probably support v6 anyway, but a bunch of services are v4-only because of the migration effort. They should be able to turn on v6 without having to change everything about their networking.
Wasn't "dual-stack hosts talking over a v4 network" what you wanted?
v4 routers don't understand and can't route v6 packets, so you can't use the same route for both of them. v6 packets have to go to a router that understands v6, and v4 packets have to go to a router that understands v4.
I have no idea what "or a superset in the later stages (shared down to /32, v6-only in deeper subnets)." is trying to say.
It's perfectly possible to turn v6 on without changing anything at all about your networking. When e.g. Windows Vista came out, hundreds of millions of people did exactly that.
Why can't the service just set up NAT64 to accept your v6 connections on their v4 servers?