Into which two types of areas would an area border router (ABR) inject a default route?
(Choose two.)
A.
the autonomous system of a different interior gateway protocol (IGP)
B.
area 0
C.
totally stubby
D.
NSSA
E.
stub
F.
the autonomous system of an exterior gateway protocol (EGP)
Explanation:
Both stub area & totally stubby area allow an ABR to inject a default route. The main
difference between these 2 types of areas is:
+ Stub area replaces LSA Type 5 (External LSA – created by an ASBR to advertise network
from another autonomous system) with a default route
+ Totally stubby area replaces both LSA Type 5 and LSA Type 3 (Summary LSA – created
by an ABR to advertise network from other areas, but still within the AS, sometimes called
interarea routes) with a default route.
Below summarizes the LSA Types allowed and not allowed in area types:
