This read-only Counter64 counts queries discarded because the ingress port was in a blocking state (for example, held down by spanning tree or an access-control action) when the query arrived. This ties multicast query loss directly to L2 loop-prevention or security state on the port, useful when troubleshooting why an IPTV stream briefly drops during a topology change; because it is drawn from this table's currently-accumulating, short-interval bin, it reflects only the last few minutes of activity, so it's the value to watch for a fast-forming problem rather than a long-term trend. On a metro aggregation uplink carrying several video EVCs, a count of 1,086 over the last 15 minutes 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.