The iburst option does several checks quickly as soon as the daemon is started and whenever the server is unreachable if you have that in your configuration. The burst option does several checks quickly whenever the server is reachable. By default ntpd then follows an exponential backoff where the time between checks progressively increases, starting … Read more
You can specify an NTP server via DHCP, or Group Policy, or DNS SRV records. DHCP: GPO: SRV Record: If your client is unable to leverage any of those mechanisms… you can also pretty safely assume that all Active Directory domain controllers are also NTP servers. Which means that you should be able to find … Read more
The best practice is to run your own pool of NTP servers set to sync from public NTP servers. In the event that your organization was to lose internet access, you would not want your clocks to become skewed. Further, it is rude to set thousands of hosts to public servers when you could (and … Read more
ntpdate (and ntpd) will refuse to (easily) set the time if the offset is too high. Both applications will try to slowly adjust your time, so as to not to confuse your system or any applications that may not handle big time jumps very well. Try ntpdate -b instead. It will set the time no … Read more
You only need to set the time zone once: tzselect or dpkg-reconfigure tzdata NTP does not handle time zones. All time data handled by NTP is in UTC; your local time zone setting determines the offset from there.
As far as I can see in the sources, ntpd handles both a member of a pool and individual servers roughly in the same way: it adds them to the list of peers. All these peers are used by ntpd. The magic of the pool mechanism is in round-robin DNS: as ntpd resolves the pool … Read more
From my reading of this page, it appears that ntp doesn’t use the INADDR_ANY 0.0.0.0 address exclusively partly for security reasons, and partly for authentication reasons. First port 123, is below 1024, and so is considered a privileged port, and only root can bind to that port. Ntp is typically set to drop privileges after … Read more
This may tell you if/where ntp activity is being logged: grep log /etc/ntp.conf You can also try: ps auxww | grep ‘[n]tp’
Firstly, good for you; it’s a helpful and public-spirited thing to do. That said, and given your clarification that you’re planning on creating one or more DMZ VMs which will sync to and make publicly-available the time from your three Meinberg GPS-enabled stratum-1 (internal) servers: Edit: Virtualisation comes up for discussion on the pool list … Read more
The NTP algorithm includes information to allow you to calculate and fix the drift in your server’s clock. NTPD includes the ability to use this to keep your clock in sync and will run more accurately than a clock on a computer not running NTPD. NTPD will also use several servers to improve accuracy. ntpdate … Read more