A Network Administrator Is in Charge of Multiple IPsec VPN

Multiple Choice

A network administrator is in charge of multiple IPsec VPN headend devices that service thousands of remote connectivity, point-to-point, IPsec/GRE tunnels. During a recent power outage, in which it was found that a backup power supply in one of those headend devices was faulty, one of the headend routers suffered a complete shutdown event. When the router was successfully recovered, remote users found intermittent connectivity issues that went away after several hours. Network operations staff accessed the headend devices and found that the recently recovered unit was near 100% CPU for a long period of time. How would you redesign the network VPN headend devices to prevent this from happening again in the future?

A) Move the tunnels more evenly across the headend devices.
B) Implement Call Admission Control.
C) Use the scheduler allocate command to curb CPU usage.
D) Change the tunnels to DMVPN.