So basically, instead of extending the v4 address space you're going to make a new stack and everybody needs to switch to it to be able to communicate with v8.

So basically, instead of extending the v4 address space you're going to make a new stack and everybody needs to switch to it to be able to communicate with v8. That's the exact thing you said you weren't doing. > If it receives 1:2:3:4:0:0:0:0, that's v4 and continues as such 1:2:3:4:0:0:0:0 isn't v4, so it can't "continue as v4"... perhaps you meant that a router somewhere converts the packet to a v4 packet, but this is still only the v8->v4 direction. How do you map v8 into v4 so that the destination can reply? > The update from 32-to-64 will be massively pushed to all kernels and userspaces in a short time so to shorten outages. Right, add support for the new stack everywhere like we did with v6's 32-to-128 update. But just saying that it'll be done in a short time doesn't mean it will be.