nanog mailing list archives

Re: Picking outside NTP servers (Re: NTP Issues Today)


From: "Majdi S. Abbas" <msa () latt net>
Date: Tue, 20 Nov 2012 18:22:35 -0500

On Tue, Nov 20, 2012 at 04:53:39PM -0500, Jay Ashworth wrote:
For myself, I usually pick the first three in us.pool.ntp.org, tick and tock,
time.nist.gov, and a couple of regionally appropriate large universities.

        I'd advise going through the RR for a while, and pick servers
close to you.  ntpd won't select a server that's more than 128ms away.
It also degrades accuracy.  Select for minimum latency, as well as
a diverse set of sources.  [Watch their refid over time, and make sure
they aren't slaving to the same set of servers, as well as others
you may be using.]

        It requires a bit of effort, but over time you get an idea what
public time servers are close to each of your locations, and diverse
from each other.

        --msa


Current thread: