What works for IPv6 today? What doesn't? What's hard to configure? * Can clients use ipv6 to connect to Tor? * Can clients resolve Ipv6 addresses with Tor? * Does automapping to ipv6 addresses work? * Can we exit to ipv6? * Can bridges be IPv6-only? (no, I don't think so) * Can relays be IPv6 only? (no) And many more. We should ideally not only hand-check tehse issues, but write tests for some of them.