> Perhaps you are too young to realize that the original IPv6 plan was
> not designed to be backward compatible to IPv4, and Dual-Stack was
> developed (through some iterations) to bridge the transition between
> IPv4 and IPv6? You may want to spend a few moments to read some
> history on this.

ROFL!!!  if there is anything you can do to make me that young, you
could have a very lucrative career outside of the internet.

hint: unfortunately i already had grey hair in the '90s and was in the
room for all this, and spent a few decades managing to get some of the
worst stupidities (TLA, NLA, ...) pulled out of the spec.  at iij, we
rolled ipv6 on the backbone in 1997.

randy