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.
