Can Dimensional Barrier Stop Links?

No you cannot use Dimensional Barrier on link monsters as this is the current text.

Is dimensional barrier good?

Dimensional Barrier can give you an advantage for a turn, but it won't win you the game if you can't capitalize on it. ... Games are so often decided in the first few turns of the duel that a card which robs your opponent of a turn might as well be a continuous floodgate anyways.

How do you use dimensional barriers?

A: You can activate "Dimensional Barrier" by arbitrarily choosing 1 Monster Card type to declare. For example, even if there are no face-up Fusion Monsters on the field, you can still declare Fusion Monster, and the effect of "Dimensional Barrier" is applied normally.