To implement communication between user hosts and a multicast network, configure basic IGMP functions on interfaces that connect multicast devices to user network segments.
After an interface on a multicast device is configured to statically join an IGMP group, the multicast device considers that the interface has static multicast group member and forwards multicast packets to this interface, irrespective of whether hosts connected to this interface request the multicast packets.
Internet Group Management Protocol (IGMP) on-demand helps to maintain IGMP group memberships and frees a multicast device and its connected access device from exchanging a large number of packets.
If you want to authenticate the sent and received IGMP messages, configure IGMP IP Security (IPsec). IGMP IPsec protects a device against attacks launched using forged IGMP messages.
The information system contains different services involving multicast packets. These services are isolated through GRE tunnels. Devices' GRE interfaces are required to have IGMP capabilities.