An administrator needs to secure RADIUS traffic between two servers. Which of the following is the BEST
solution?

A.
Require IPSec with AH between the servers

B.
Require the message-authenticator attribute for each message

C.
Use MSCHAPv2 with MPPE instead of PAP

D.
Require a long and complex shared secret for the servers

Explanation:
IPsec is used for a secure point-to-point connection traversing an insecure network such as the Internet.
Authentication Header (AH) is a primary IPsec protocol that provides authentication of the sender’s data.