Status/action for the resolver's negative response cache. enabled(1) means that the use of the negative response cache is allowed. Query operations can return this state. disabled(2) means that the negative response cache is not being used. Query operations can return this state. Setting this variable to clear(3) deletes the entire contents of the resolver's negative response cache. The status will retain its previous value from before the clear operation (i.e., enabled(1) or disabled(2)). The value of clear(3) can NOT be returned by a query operation.