Some kind of explaining for [IPv6.reg](IPv6.reg) like
[Windows.reg](Windows.reg) which includes this file has.

- Resolve IPv6 even without native connectivity.
- Enable Teredo
  - As EnterpriseClient so it also works when joined into domain.
- Use `teredo.trex.fi` as Teredo server. This should be replaced with
  something that is as near as possible.