<p>The Internet of Things refers to a collection of closely connected devices that form a network through wireless or wired communication technology that work together to achieve common goals for their users. The IoT devices that are distributed in nature may cause the system to suffer from server crashes, server omissions, incorrect responses, and arbitrary errors. In this paper, we present a method of fault tolerance in IoT networks using graph theory approach to ensure the robustness of the network in case of attacks or disconnections through the concept of domination vertex connectivity in graphs. We further study this parameter in case of the Tensor product and Lexicographic product of specific graph classes, which have major implications in IoT networks.</p>