Some nice Theory to help you ...
NSSA External LSAs are originated by ASBRs within not-so-stubby areas (NSSAs). An NSSA External LSA is almost identical to an AS External LSA. Unlike AS External LSAs, which are flooded throughout an OSPF autonomous system, NSSA external LSAs are flooded only within the not-so-stubby area in which it was originated. The command show ip ospf database nssa-externaldisplays NSSA external LSAs
Not-so-stubby areas(NSSAs) allow external routes to be advertised into the OSPF autonomous system while retaining the characteristics of a stub area to the rest of the autonomous system. To do this, the ASBR in an NSSA will originate type 7 LSAs to advertise the external destinations. These NSSA External LSAs are flooded throughout the NSSA but are blocked at the ABR.
The NSSA External LSA has a flag in its header known as the P-bit. The NSSA ASBR has the option of setting or clearing the P-bit. If the NSSA's ABR receives a type 7 LSA with the P-bit set to one, it will translate the type 7 LSA into a type 5 LSA and flood it throughout the other areas. If the P-bit is set to zero, no translation will take place and the destination in the type 7 LSA will not be advertised outside of the NSSA.
!HTH Saludos, Victor