Libero attack / attack over the net

[DaveASA/FED]

ok, I have two questions but they are around the same topic, ball vs plane! I know the libero (speaking NFHS rules) can not attack the ball anywhere (attack line does not matter) on the floor, but where does the ball have to be? My understanding is that the ball has to be completely above the net for this to be an illegal attack. Meaning that if a plan parallel to the floor was extended and any part of the ball hits that plane then she is legal on the attack. Is this correct? Or does it have to be completely below this plane?

Same type of question on attacking over the net. I thought if the ball has broken the plane of the net, plane extending from the top of the net to the ceiling as long as the ball has touched this plane the "defense" is ok to attack that ball.

All help is appreciated.

Thanks.