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Software defined networking emerges as a promising paradigm shift that decouples the control plane from the data plane. It has the ability to centrally monitor and control the network through softwarization, ie, controller. Deploying a single controller is inefficient to handle large network traffic; thereby, making multiple controllers are a necessity of current software defined networking in wide area networks. Placing multiple controllers in an optimum way, ie, controller placement is a vibrant research problem. Controller placement problem (CPP) is of twofold: the minimum number of controllers to be placed in a network and locations of these controllers. Numerous researchers in the last 5 years (2012 to November 2017) have proposed solutions for the CPP, which is an NP‐hard problem. In general, solutions are based on objective functions and their optimum solutions considering various factors (such as propagation …