I aleady have each device in a VLAN and have disabled “Multicast Router” for each interface, but I don’t know whether that disables multicast on layer 2. I know with EBTables there is a simple packet-type drop rule, but to what does that equal in MikroTik IP Bridge Firewall syntax? I think that command still only drops layer 3 packets. It would be best to drop all multicast frames, but layer 2 multicast MAC includes broadcast MAC and dropping it may stop all traffic.