wfBgpBlackHoleSupport 1.3.6.1.4.1.18.3.5.3.2.5.1.1.23

If this switch is disabled BGP doesn't submit a 'black-hole' route into IP routing table for an aggregate route advertised to a BGP peer. For action 'drop' packet will be dropped and for 'reject' - 'ICMP Destination Unreachable' will be send back.