alt Hacker News> If I have 1.2.3.4 in ipv4 world, I want 1.2.3.4 in ipv6 world instead of a random new address.
::ffff:1.2.3.4
* https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresse...
By having 1.2.3.4 you also got 2002:1.2.3.4::/48 'for free' (per 6to4). So if you want to send things to 1.2.3.4 / ::ffff:1.2.3.4, you tell your router that it's available via 2002:1.2.3.4::/48.
Any idea that you think is clever and to 'just' do X and/or Y for IPng, and would work, has probably already been thought of and attempted in the last 20-30.
Having 1.2.3.4 in v4 doesn't make ::ffff:1.2.3.4 or 2002:1.2.3.4 route to me in v6. It would route to a relay that translates/resends to v4 1.2.3.4, then it reaches my router over v4. Nobody can use that address over pure v6.
There's no one clever trick to make the transition easy, the idea is to preserve the v4 address blocks in v6. That cascades down to a bunch of different decisions, some of which include keeping NAT around. They've most likely thought of that too, and turned it down because they wanted to start with a clean slate and maybe also had some other vision of pure P2P apps.