This counter records the total number of multicast IP packets the router has forwarded onto its Ethernet interface. Since satellite links are often used to multicast the same content to many receive sites at once, this counter is the best signal that multicast distribution is actually reaching the local network; if it stalls while cdd564IGMPPacketsReceived keeps incrementing, IGMP group membership isn't translating into forwarded multicast traffic. On a site provisioned for a multicast video feed, an admin would expect this counter to climb continuously and would treat a flatlined value as a sign the multicast forwarding path, not the tuner, has failed.