This read-only Counter64 counts IGMP packets received with a message type this switch's snooping/proxy code doesn't recognize. A steady count usually means a host or router on that segment is speaking a newer or vendor-specific IGMP variant, rather than signaling an active fault; because it is drawn from the most recently completed 24-hour bin, frozen once the day rolled over, it is frozen and safe to use for day-over-day comparison, since no further traffic will ever be added to it. On a subscriber-facing IPTV access port, a count of 2,505 over the last completed collection window 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.