OSPF - Type 5 LSA filtering on an ASBR

Filtering Type 5 LSAs in OSPF can be applied at the ASBR. This can be done using a distribute list, redistribution, or the summary address feature. When any of these are configured, the Type 5 LSA actually never enters the OSPF database on the ASBR. The filtering occurs before the route enters any OSPF processes.

If filtering is applied to the ABR then the Type 5 LSA enters the OSPF database of the ASBR, is propagated throughout the local area, but is not further advertised into the backbone area.

https://networklessons.com/ospf/ospf-lsa-type-5-filtering-on-cisco-ios