Named Data Networking (NDN) has been recently touted as one of the most appealing future Internet architectures. One prominent feature in NDN networks is the in-network caching that allows routers to store content in their cache and directly serve it to end-users. In this context, efficiently forwarding content requests to the closest router having the desired content has been a daunting challenge that still needs to be addressed. To tackle this challenge and inspired by software defined networking paradigm, we recently proposed a controller-based NDN caching and forwarding scheme where multiple controllers cooperate to efficiently handle request forwarding in the network [1]. In this paper, we further explore this solution by addressing two related challenges: 1) determining the optimal number of controllers able to handle the network traffic; 2) find an optimal placement for the controllers that minimizes the controller load and the inter-controller latency. We first formulate the controller placement problem as an integer linear program and then study the performance of two potential clustering-based solutions. Extensive simulations using real network topologies show that these solutions can provide near-optimal controller locations which, in turn, improve the performance of controller-based NDN forwarding schemes in terms of data download latency and throughput.