Route Aggregation

Hello,

Does anybody found a solution how to make aggregation route advertised over BGP only, if there is active contributing route?

BR,
Dmitri

http://forum.mikrotik.com/t/bgp-v7-aggregation-how-to/156688/1
http://forum.mikrotik.com/t/bgp-aggregate-address-alternative-in-mikrotik/160945/1

Yes, already checked these links (link in the first thread is not available anymore), but i asked how to make aggregated route advertised while there is active contributing route?
At this moment aggr route advertised always.