Issues with multicast on an isolated Layer 2 Network

Hi all,

I am troubleshooting an SCCM multicast issue for a client and wanted to confirm something before I look at the SCCM configuration and server specs. The network is non-routable and doesn't even have a router attached. In fact all switchports (including the SCCM server) are in VLAN 1 - and VLAN 1 does not have an IP address assigned. There is no requirement to.

The switches are all Cisco 3650 switches with IGMP Snooping enabled but default.

My question - Will IGMP Snooping work without a router? I've done a little research and it seems that an IGMP Snooping Querier is required in the absence of a Multicast Router.

Is this correct? If so, do I need to configure only a single SVI on a single switch as an IGMP querier? Or do I need to configure a querier on all switches within the domain.

Is there any additional config I should be aware of to optimise multicast traffic?

I will be heading out tomorrow to troubleshoot.

Thanks!