OSPF - Filter redistribution in a Totally NSSA area

In some cases, we can have the ABR which can also be an ASBR. If we are working with a Totally NSSA area we have unnecessary routes. ABR announces a default route and his redistributed routes which are not necessary. In order to solve this case and only announce a default route, we can use the commande below on the ABR:

 area X nssa no-redistribution no-summary

The schema below is anexample of this implementation: