Refer to the exhibit.

Switch 1 and switch 2 run open Shortest Path First (OSPF) on all VLANs. Both switches establish an OSPF
adjacency to a router at the main data center. Exhibit shows shoes some virtual Routing Redundancy Protocol
(VRRP) and OSPF settings on Switch 1 during normal operation.
How can a network administrator increase the resiliency of this solution?

A.
Implement Bidirectional Forwarding Detection (BFD) on the peer keep alive link between the core switches.

B.
Change the VLAN 10 subnet to a /24 subnet and enable VRRP on it. Place Switch 2’s link to the main data
center in this subnet.

C.
Make sure that, in each VRRP instance, each switch has a VRRP preempt delay of several minutes.

D.
Configure Switch 1 as an OSPF graceful restart helper in VLAN 11 and Switch 2 as a helper in VLAN 10

Explanation:
Today many Internet routers implement a separation of control and forwarding functions. Certain processors
are dedicated to control and management tasks such as OSPF routing, while other processors perform the
data forwarding tasks. This separation creates the possibility of maintaining a router’s data forwarding capability
while the router’s control software is restarted/reloaded. We call such a possibility “graceful restart” or “non-stop
forwarding”.
RFC 3623, Graceful OSPF Restart
https://tools.ietf.org/html/rfc3623