The Internet of Things (IoT) is characterized by a myriad of communication protocols that enable seamless connectivity among devices. However, the open nature of the internet exposes these communication protocols to various flaws and vulnerabilities, resulting in the necessity for rigorous security verification. In response to this imperative, the literature abounds with research efforts aimed at assessing the security properties of IoT communication protocols using diverse techniques. In this paper, we present a comprehensive overview of these research endeavors, with a specific focus on the utilization of Formal Methods to verify the security of common communication protocols employed in the IoT.