This counter reports the total bytes of Layer-2 multicast traffic on this port that exceeded the configured flood/storm-control threshold and were therefore dropped rather than forwarded, during the entire life of the counter to date. Because this figure accumulates over its entire tracked lifetime and, unlike its clearable Stats-bin counterpart, defines no clear-time field at all, a single step-change in an otherwise-flat trend is a permanent record that a Layer-2 multicast flood happened at some point on this port, caused by an unregistered multicast stream that no IGMP membership ever pruned to specific ports, even after the underlying cause is long gone and any Stats-bin clear has erased the interim view. For example, a total that jumps by several megabytes in one day because of an unregistered multicast stream that no IGMP membership ever pruned to specific ports, and then stays perfectly flat for months afterward even through a Stats-bin clear, tells you that particular Layer-2 multicast flood was a single past incident already resolved, rather than something still actively happening today.