This chapter describes how with the rapid increase of internet users, more people have access to global information and communication technology. As a result of which, the issues of using the internet as a global platform for the enabling of smart objects and machines to coordinate, communicate, compute and calculate, gradually emerge. In Mobile Ad-hoc Networks (MANETs) the individual nodes are self-reconfigurable according to the changes of the network topology. Joint effort between portable hubs is more critical because they face major challenges such as powerlessness to work safely while protecting its assets and performing secure steering among hubs. With the existence of malicious nodes, one of the principal challenges in MANETs is to outline powerful security arrangement that can shield MANETs from various routing attacks. This chapter highlights major attacks and control mechanism in MANETs with an intention that it will open directions for researchers to explore more in the field of network security. At the end of this chapter, basic security mechanisms and issues related to emergence of IoT from Mobile networks has been highlighted.