On 5/10/2016 11:22 AM, Leo Bicknell wrote:
In a message written on Mon, May 09, 2016 at 11:01:23PM -0400, b f wrote:
In search of stable, disparate stratum 1 NTP sources.
http://wpollock.com/AUnix2/NTPstratum1PublicServers.htm
We tried using “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.
Depending on your hardware platform your Cisco Router is likely not a great NTP server. IOS is not designed for hyper-accuracy.
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.
The correct answer here is to run multiple NTP servers in your network. ... [snip]
I think the correct answer here starts with a question --- what level of time accuracy is required for the local NTP server(s)? Which then begs the question, what level of accuracy is needed for the clients? A shop with a client need for nanosecond accuracy begs for an entirely different solution set than a shop where a millisecond of accuracy is needed on the clients, and still a different solution set that a shop where "a few milliseconds either way" is quite OK.