The IGMP Querier is a device (usually a Layer 3 switch or router) that actively sends IGMP query messages to manage multicast group membership on a network.
The querier asks devices on the network: “Do you still want this multicast stream?” Receivers respond with IGMP membership reports if they still need the traffic.
In ST 2110 systems, video and audio flows rely on multicast. Without a functioning IGMP Querier, multicast streams may stop flowing, causing no video or no audio reception.
If no querier exists on the VLAN:
Ensure one Layer 3 device in the VLAN is configured as the IGMP Querier, or that a router is actively sending IGMP queries at regular intervals.
