IP address autoconfiguration of mobile nodes is highly desirable in the practical usage of most mobile ad hoc networks (MANETs). This paper proposes cluster-based autoconfiguration, a novel approach for the efficient address autoconfiguration of MANETs. The cluster structure derived from clustering techniques is used to manage address assignment and conflict resolution. By introducing the concept of virtual address agents (AAs), the proposed approach can be applicable to many existing clustering protocols. Finally, analysis and simulation demonstrate that the proposed scheme outperforms the previous autoconfiguration approaches.