An instruction from a controller is received at an application executing using a processor, the controller being a Software Defined Network (SDN) controller operating in an SDN. A determination is made, using the processor, that the instruction applies to an identifier located in a data packet, the data packet passing through a shared port, the shared port being shared by the controller and a concurrently operating second controller in the SDN. A period of effectiveness of the instruction is initialized. A command is sent to a switch to apply a network setting configured by the controller to handle the data packet, where the shared port is located at the switch in the SDN.