I have three Catalyst 4507R-E switches networked which contain a number of security devices. The last of which to be added on are IP security cameras/servers which use multicasting. My question is, is there a way to enable one of these switches to act as the querier for the network?
AFAIK only the supervisor 6E has support for the IGMP querier function. You only need this if you are running multicast within the same vlan and are not using multicast routing.
If you need multicast routing then as Guiseppe says you can enable pim on the vlan interfaces and this will enable IGMP by default.
enabling ip multicast-routing and ip pim sparse-dense mode on the interface provides also the IGMP querier function that allows to use IGMP snooping that need to listen to all IGMP reports.
on release 12.2.46 sg I didn't find a command for igmp querier that would be useful if devices are working only at layer 2.
I think it is supported on C6500 on same releases.
Hope to help