Network administrators employ a variety of security policies to protect the data and services. However, the lack of standard control protocol and distributed network control causes these policies to be complicated in traditional networks. An ideal paradigm is provided by Software Defined Network (SDN) to address these challenges through separating the control plane from data plane. Security policies are enforced by logically centralized control's which take advantage of SDN. In this paper, we present a fully configurable system for an institution using POX which is a famous SDN controller. A network administrator can enforce the policies related to security, access and control through it. So that a single change in policy will be reflected in all the OpenFlow switches, attached to the SDN, resulting in reduced cost and time, as compare to the conventional networks where each switch is managed individually. The purpose of this research is to achieve a secure and controllable SDN by blocking the malicious and restricting the anonymous users in the network.