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 current, still-open 24-hour bin for today, the number keeps climbing until midnight rollover, so it should be read as "so far today" rather than a finished daily total. On an uplink toward the multicast-enabled core router, a count of 2,189 over today so far 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.