You can configure the ABR route aggregation to convert the routes with the same prefix to one Type-3 LSA on the ABR and send it to other areas.
You can choose whether to advertise the aggregated route, and configure the cost of the aggregated Link State Advertisement (LSA).
This command is applicable only to ABRs and is used for the route aggregation in an area. The ABR transmits only an aggregated route to other areas. Route aggregation refers to that the ABR can aggregate routes with the same prefix, and send only one route to other areas. You can configure multiple network segments in an area. OSPF can thus aggregate multiple network segments.
ospf [ process-id ]
area area-id
abr-summary ip-address mask [ cost { cost | inherit-minimum } | [ advertise [ generate-null0-route ] | not-advertise | generate-null0-route [ advertise ] ] ] *
This command is valid for ABRs only.