You can configure ASBR routers in various ways to summarize the routes to different areas. This summary will be advertised, by default. The aggregating routes can be internal address range or AS-external address range. You can configure area parameters only after enabling the OSPF process. Configure these parameters in Router Configuration mode.
Internal address ranges are one of two types:
Type-3 aggregation
Type-7 translation aggregation
For AS-external address range aggregation, Type-5 and Type-7 address ranges can be aggregated, and Type-5/Type-7 LSA conversion and generation can also be configured.