Network Time Protocol (NTP) synchronizes computer clock times across a network. Your XTM device can use NTP to get the correct time automatically from NTP servers on the Internet. Because the XTM device uses the time from its system clock for each log message it generates, the time must be set correctly. You can change the NTP server that the XTM device uses. You can also add more NTP servers or delete existing ones, or you can set the time manually.
To use NTP, your XTM device configuration must allow DNS. DNS is allowed in the default configuration by the Outgoing policy. You must also configure DNS servers for the external interface before you configure NTP.
About the DNS-Proxy