Let's look at what we've configured in the above screenshot:
1) We enabled IGMP Snooping globally for the switch.
2) We enabled IGMP Snooping Enhanced Mode. Moxa recommends enabling this setting only if the network is all Moxa switches. If there are Cisco or other third party switches in the network, leave this setting disabled.
3) We enabled IGMP Snooping and Querier for the particular VLAN (only default VLAN available in this example).
You can use the above for all managed switches in the network. It's ok to set multiple switches as queriers because Moxa uses Protocol Version 2. This version includes an election process so only one switch will actively perform the querier role, but you'll have others available to perform the task if that switch goes down.
Links of Interest