On the use of multiple MAC registration protocol in industrial networks Large industrial automation networks based on Real-Time Ethernet protocols may need efficient multicast management and filtering in order to control traffic load and to guarantee the desired quality of service. Very often industrial network are required to be highly available, implying the use of redundancy protocols, and thus, the use of dynamic (layer 2) multicast reconfiguration may be effective. This paper evaluates the application of standard IEEE Multiple MAC registration Protocol(MMRP) to industrial automation scenarios. Two main application fields are considered: large (and slow) process automation plants; and fast factory automation networks inside electric substations for measuring and protection. Following analytical and simulation approaches complete model of MMRP has been developed. Last, a new set of protocol parameters is proposed to maximize effectiveness of MMRP in industrial scenarios: a great network load reduction and a multicast reconfiguration time of 40 ms after a fault can be obtained in networks with complex topology.