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 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 an access port serving a multi-dwelling unit, a count of 162 over the 41 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.