A stpxMstInconsistencyUpdate notification is sent by a bridge when an instance of stpxMstInconsistencyState is created or destroyed. That is, when an type-inconsistency is discovered in instance's Spanning Tree for a particular port, or when such a type-inconsistency disappears. Note that the trap is not sent if the port transitions between different types of inconsistency. The stpxMstInconsistentState value indicates the type of inconsistency which now exists/no longer exists for the relevant instance on the relevant port.