Define an authentication key for Network Time Protocol (NTP). Rationale: Using an authentication key provides a higher degree of security as only authenticated NTP servers will be able to update time for the Cisco device. Impact: Organizations should establish three Network Time Protocol (NTP) hosts to set consistent time across the enterprise. Enabling the 'ntp authentication-key' command enforces encrypted authentication between NTP hosts.
Solution
Configure at the NTP key ring and encryption key using the following command hostname(config)#ntp authentication-key {ntp_key_id} md5 {ntp_key_hash} Default Value: No authentication key is defined for NTP.