Information
Sets the key used to authenticate NTP servers
Rationale:
When authentication is not enabled, attackers can disguise as NTP servers and broadcast wrong time and it will be difficult to correlate events upon an incident. In some other cases, attackers can perform NTP DDoS attacks such as NTP Amplification.
Solution
* Step 1: Run the following to set the authentication key ID <key_id>
HOSTNAME(CONFIG)# NTP TRUSTED-KEY _<key_id>_
* Step 2: Run the following to configure the authentication key <authentication_key>
HOSTNAME(CONFIG)# NTP AUTHENTICATION-KEY _<key_id>_ MD5 _<authentication_key> _