NIST NTP servers

Tue May 10 20:29:26 UTC 2016

> On May 10, 2016, at 4:21 PM, Harlan Stenn <stenn at ntp.org> wrote:
> 
>> Configure all of your devices to get NTP from the servers you run
>> using authentication.
> 
> Yes, and properly monitor your ntpd instances.

And upgrade them.

Some software distributors don’t ship modern software.  if you
are using a distribution packaged ntpd it’s likely old and
difficult to determine its lineage due to how it’s packaged.

If you’re using Redhat based systems consider using chrony 
instead, even the new beta fedora 24 uses 4.2.6 derived code
vs 4.2.8

- Jared