In a large enterprise network with multiple data centers and thousands of access devices, OSPF is
becoming unstable due to link flapping. The current design has the access devices multihomed to
large aggregation routers at each of the data centers. How would you redesign the network to
improve stability?

A.
Add a layer of regional Layer 3 aggregation devices, but leave the ABR function on the data
center aggregation routers.

B.
Add a layer of regional Layer 2 aggregation devices, but leave the ABR function on the data
center aggregation routers.

C.
Add a layer of regional Layer 3 aggregation devices and move the ABR function to the regional
aggregation device.

D.
Add a layer of regional Layer 2 aggregation devices and move the ABR function to the regional
aggregation device.