> Last example of three is impossible with IPv4/6 dichotomy, and is most important for backward compatibility here - yes, "old" IP holder needs to upgrade their

> Last example of three is impossible with IPv4/6 dichotomy, and is most important for backward compatibility here - yes, "old" IP holder needs to upgrade their software too[1], but they don't need to get a new IP address, and as a result you don't end up with two isolated "Internets", a.k.a. dual-stack. 1. What would be a scenario where hosts using this mechanism could communicate where neither IPv4 nor IPv6 would work? 2. How do new internet participants get addresses under your scheme, if it only expands the number of addresses in existing allocations?