Which two mechanisms are available to secure NTP? (Choose two.)
A . IP prefix list-based
B . IPsec
C . TACACS-based authentication
D . IP access list-based
E . Encrypted authentication
Answer: D E
Explanation:
The time kept on a machine is a critical resource and it is strongly recommend that you use the security features of NTP to avoid the accidental or malicious setting of incorrect time.The two security features available are an access list-based restriction scheme and an encrypted
authentication mechanism.