Yes, we have a Blackhole community 9002:666, for more information see the BGP Communities section. A blackhole announced by a client gets validated (i.e., it is verified whether the best path to the announced more specific route is chosen via this IP-transit BGP session) and is spread throughout the RETN’s network. The maximum amount of blackhole routes that can be received from one BGP-neighbour cannot exceed 100 routes.