This read-only Counter64 counts IGMP packets received with an invalid IP checksum. Checksum failures point to link-layer corruption or a failing NIC/cable upstream of this port rather than a protocol issue, so admins treat a rising count here as a physical-layer lead; because it is drawn from the lifetime bin, which keeps accumulating until an operator explicitly clears it, a sudden plateau on an otherwise busy instance is itself a signal — most likely that someone cleared the stats rather than that traffic actually stopped. On a metro aggregation uplink carrying several video EVCs, a count of 3,307 over the 85 days since the counters were last cleared is the kind of number an admin would trend against the join/leave rate on the same port to judge whether it's normal channel-surfing or an anomaly worth a closer look.