Click the Exhibit button.
The four routers in the exhibit are participating in a multi-area OSPF topology.
Node B (in the upper right-hand corner) is an ASBR advertising an external route.
Node A (lower left-hand corner) receives the external route and begins to forward traffic to the ASBR.
How many hops will the packets take through this topology? (Do not count node A.)
The four routers in the exhibit are participating in a multi-area OSPF topology.
Node B (in the upper right-hand corner) is an ASBR advertising an external route.
Node A (lower left-hand corner) receives the external route and begins to forward traffic to the ASBR.
How many hops will the packets take through this topology? (Do not count node A.)
A.
2
B.
3
C.
4
D.
5
Can someone explain why it takes 4 hops? Why not take the shortest path with the lowest cost by going across the link with metric 10 and 1 hop instead the longest and most expensive path?
OSPF will choose routes in the following order:
Intra-Area (O)
Inter-Area (O IA)
External Type 1 (E1)
External Type 2 (E2)
NSSA Type 1 (N1)
NSSA Type 2 (N2)
Router3 is only ABR that can advertise LSA4, so traffic has to pass it.