In order to advertise
a summary route you can use the "aggregate route" feature. This command will advertise a summary route such as 10.0.0.0/8 when a more specific route (10.10.10.0/24) is present in the BGP table. You can add a summary option to the command which will suppress advertisement of the more specific routes and only advertise the larger 10.0.0.0/8 route. Normally redistribution or a bgp network statement would be used to populate the BGP table with the support routes.
router bgp 1234
aggregate-address 10.0.0.0/8 summary