Billions of devices are expected to be Internet-enabled by 2020, levering the Internet of Things (IoT). Device discovery is a problem of finding useful devices in order to accomplish a task, and it constitutes a major challenge for IoT. Once a device finds another with the desired characteristics and establishes a negotiated communication, novel services can be generated through cooperation. Several efforts to solve the discovery problem have been proposed, focusing on different aspects of the process: service description, index organization, query definition, communication protocol, etc. In the present work, we focus on the topology of a network of devices and how it influences discovery. Three network topologies are evaluated using multi-agent simulations: (1) centralized, (2) decentralized and (3) hierarchical. These topologies are assessed with respect to discovery time, server-side infrastructure, reliability, and network traffic. Moreover, the obtained results have been used to design an IoT registry infrastructure.