@jon said in Multicast receiver Issue: import socket import pycom server_address = ('', 10001) sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) #supposedly automatically works out the socket cast type?? sock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1) sock.bind(server_address) def rxstream(item1, item2): try: print('starting rxstream') #sock.settimeout(5) while stop > 0: print('before') data, address = sock.recvfrom(64) print('recieved %s from %s port %s' % (data, address[0], address[1])) except OSError as err: print('unexpected exception - on rx stream socket %s' % (err)) except: print('hmmm') finally: print('bye ') pycom.rgbled(0x0000ff) time.sleep(1) _thread.start_new_thread(rxstream, (1,2)) It would seem this is not currently supported in micropython: https://github.com/micropython/micropython/issues/2691 But it is supported in the ESP32 IDF so you could do this in C and make a micropython module if you wanted. See: https://github.com/espressif/esp-idf/tree/master/examples/protocols/udp_multicast