Let (A, G) be a C*-dynamical system with G discrete. In this paper we investigate the ideal structure of the reduced crossed product C*-algebra and in particular
we determine suﬃcient—and in some cases also necessary—conditions for A to separate
the ideals in A ⋊r G. When A separates the ideals in A ⋊r G, then there is a one-to-one
correspondence between the ideals in A ⋊r G and the invariant ideals in A. We extend
the concept of topological freeness and present a generalization of the Rokhlin property.
Exactness properties of (A, G) turns out to be crucial in these investigations.