Refer to the exhibit.

Routers R2, R3, R4, and R5 have OSPF enabled. What should be configured on the routers in
area 1 to ensure that all default summary routes and redistributed EIGRP routes will be forwarded
from R6 to area 1, and only a default route for all other OSPF routes will be forwarded from R5 to
area 1.

A.
R5(config-router)# area 1 stub
R6(config-router)# area 1 stub

B.
R5(config-router)# area 1 stub no-summary
R6(config-router)# area 1 stub

C.
R5(config-router)# area 1 nssa
R6(config-router)# area 1 nssa

D.
R5(config-router)# area 1 nssa no-summary
R6(config-router)# area 1 nssa

Explanation:
External RIP routes are being routed in OSPF area 1 where they are injected as type 7 so we use
(area 1 NSSA) command on the ASBR(R2) and
(Area 1 NSSA no-summary) command on R3 and R4.
You can verify issuing the command “show ip ospf database” and you will see the type 7 lsa’s on
ASBR(R2) and LSA’s Type 5 and 7 on both the ABR routers(R3 ,R4)