nanog mailing list archives

Re: NIST NTP servers


From: Spencer Ryan <sryan () arbor net>
Date: Mon, 9 May 2016 23:09:33 -0400

I would second the idea of using your own GPS appliance if possible.
On May 9, 2016 11:08 PM, "Mel Beckman" <mel () beckman org> wrote:

NTP has vulnerabilities that make it generally unsuitable for provider
networks. I strongly recommend getting a GPS-based time server. These are
as cheap as $300. Here is one I use quite a bit:

http://www.amazon.com/TM1000A-GPS-Network-Time-Server/dp/B002RC3Q4Q

You’ll have a stratum 1 clock on site. Hard to beat.

 -mel

On May 9, 2016, at 8:01 PM, b f <freetexwatson () gmail com<mailto:
freetexwatson () gmail com>> wrote:

Hello List,


In search of stable, disparate stratum 1 NTP sources.

Looking for anyone’s advice/experiences (good/bad/ugly/weird) using NIST’s
NTP servers per: http://tf.nist.gov/tf-cgi/servers.cgi

We tried using “time.nist.gov<http://time.nist.gov>” which returns
varying round-robin addresses
(as the link says), but Cisco IOS resolved the FQDN and embedded the
numeric address in the “ntp server” config statement.



After letting the new server config go through a few days of update cycles,
the drift, offset and reachability stats are not anywhere as good as what
the stats for the Navy time server are - 192.5.41.41 / tock.usno.navy.mil.


I would greatly appreciate and feedback / advice, etc.


Thanks!!!


Ed




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