The VANET faces numerous challenges like dynamic network topology and uneven vehicle distribution. The application heterogeneity poses additional challenges in VANET deployment and routing. The software-defined network is a promising paradigm to solve the heterogeneous application services of VANETs. Efficient separation of the data plane from the control plane in software-defined networks effectively meets the heterogeneous application challenges of VANETs. It also permits the fundamental network deployment and management operations at the top of a logically centralized controller.