You only need one of them configured on the switch were your core AV device is that discovers all the A/V devices on the network(and put the querier on the correct vlan). You also only need the IGMP querier if they are on separate switches. We had a Shure vendor tech support try and tell us that the Mics didn't support vlans but that was just them trying to blame our network for audio streams making it to the core device but getting silently ignored(when they had been working for years before without issue). ... View more

Unfortunately months passed and they promised it would be resolved in an update but I never found that to be the case and I let the support case slip away. They did acknowledge the issue but we had to go with no LACP aggregation since the QSYS core could never multicast discover any of the devices. We had other issues with Meraki surrounding the AV system such as needing to force  port speed on the QSYS I/O flex devices to 1Gbps along with needing to set port speed on the QSYS TSCs to 100Mbps...That could have been the devices fault though ... View more

Thanks so much for your detailed explanation. Helped me understand how to design our network for QSYS Audio/Video install. One problem I ran into that I couldn't figure out is that IGMP querier did not make it past an aggregated link between Merakis. Traffic passed to the other trunked aggregate port of switch but could not make it to the devices needing to discover or receive. I had to split the LACP port aggregation to get it to work. Had been banging my head against this for hours. I will be reporting this to Meraki support. We really need to port aggregation to work so its an issue that we cannot discover devices with it.   -Isaac ... View more