Why do large OSPF networks use a hierarchical design? (Choose three.)
A.
to decrease latency by increasing bandwidth
B.
to reduce routing overhead
C.
to speed up convergence
D.
to confine network instability to single areas of the network
E.
to reduce the complexity of router configuration
F.
to lower costs by replacing routers with distribution layer switches
Explanation:
OSPF implements a two-tier hierarchical routing model that uses a core or backbone tier known as
area zero (0). Attached to that backbone via area border routers (ABRs) are a number of
secondary tier areas.
The hierarchical approach is used to achieve the following: