Information
Ensure you authenticate the identity of a system to which Network Time Protocol (NTP) will synchronize
Rationale:
This authentication function provides protection against accidentally synchronizing the system to another system that is not trusted, because the other system must know the correct authentication key.
Impact:
Organizations should establish three Network Time Protocol (NTP) hosts to set consistent time across the enterprise. Enabling the 'ntp trusted-key' command enforces encrypted authentication between NTP hosts.
Solution
Configure the NTP trusted key using the following command
hostname(config)#ntp trusted-key {ntp_key_id}
Default Value:
Authentication of the identity of the system is disabled.