An effective introduction of distributed generation (DG) into existing distribution networks (DNs) calls for a review of traditional power system protection concepts and strategies. New issues such as activeness of DNs and bidirectional power flow require new protection solutions. This paper discusses protection issues and challenges arising from the integration of DG into the grid. It presents and critically reviews traditional and state of the art protection strategies. Moreover, some alternate protection strategies are proposed and their merits and demerits are discussed.