If Network Time Protocol is not authenticated, an attacker can introduce a rogue NTP server. This rogue server can then be used to send incorrect time information to network devices, which will make log timestamps inaccurate and affect scheduled actions. NTP authentication is used to prevent this tampering by authenticating the time source.
Configure the router to authenticate NTP sources using authentication that is cryptographically based as shown in the example below. [edit system ntp] set authentication-key 1 type md5 value xxxxxxxxx set authentication-key 2 type md5 value xxxxxxxxx set server x.x.x.x key 1 prefer set server x.x.x.x key 2 set trusted-key [1 2] Note: SHA1 and SHA2-256 are supported with release 18.2.