This paper studies the fault management in mobile ad hoc networks. We focus on schemes which provide the robustness in MANETs: service restoration and service protection. Firstly, we propose an analytical comparison of service restoration, in terms of restoration time, at the routing layer (reactive and proactive protocols). Service restoration with reactive protocol is the most suitable in MANETs. The second motivation of the paper is an analytical study of the service protection at the network layer (multipath routing protocols) and its interest in terms of restoration time and reliability. The advantage of route redundancy in terms of restoration depends on the probability that alternate route is running after the primary route failure. The value, of this probability is studied, according to the used link connectivity maintenance mechanisms: Link-Layer Feedback Acknowledgements (LLF), Hello messages and Network-Layer Acknowledgements [1]. In terms of reliability, the multipath protocols are always better than unipath protocols. Segment recovery is the best recovery policy in terms of reliability.