Many teams defend the skip pass by having the opposite low post (X3) rotate out to the wing. X3 will then drop back down once the outside defenders catch-up in their rotation.
The 2-3 (or 2-1-2) zone defense is the most commonly used zone defense, designed to stop the inside game. The 2-1-2 zone is the same as the 2-3, except that the middle low defender is positioned a little higher in the paint, so the terms can be used interchangeably. Good outside shooting can rip this zone apart. But you still need to get the ball inside, especially late in the game, or when your shooters are not hitting.
First read Zone Offense. Mostly we attack zones with a general zone offense like "Zone-23" below and just work that offense. Usually that is all we need to do, as long as we execute well and are patient, make the zone shift, and work the ball inside.