Controller watch port for robust software defined networking (SDN) system operation

A method by a first controller in a software defined networking (SDN) network for programming a switch in the SDN network to use a controller port as a watch port. The method includes generating an instruction for the switch to create a first group entry for a first group in a packet processing pipeline of the switch, where the first group entry includes a first bucket that specifies a first controller port as a watch port and an action for the switch to forward packets to the first controller via the first controller port, where the first controller port being specified as the watch port in the first bucket indicates that execution of the action specified by the first bucket is to be contingent upon a liveness of the first controller port and sending the instruction to the switch to cause the switch to create the first group entry.