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