MANETs are self-organizing networks composed of mobile wireless nodes with often scarce resources. Distributed applications based on the P2P paradigm are by nature good candidates to run over such networks. To profit from the service provided by a P2P overlay (e.g. file sharing using BitTorrent), a peer needs to be permanently informed about the other members of the overlay (e.g. other peers interested in the same file as currently provided by the BitTorrent central tracker). However, this P2P membership management is a costly and difficult task in a dynamic and resource limited environment as a MANET. We focus on this problem and we propose a robust, network friendly and decentralized membership management protocol allowing peer discovery and update. Compared to flooding, client-server or multicast based approaches, our protocol achieves significantly lower network overhead and less pollution of global view caused by peers who have left. Moreover, as network splits are very frequent ...