On Feb 7, 2014, at 10:56 AM, Matthew Huff <mhuff@ox.com> wrote:
Working in the financial world, the best practices is to have 4 ntp servers (if not using PTP).
1) You need 3 to determine the correct time (and detect bad tickers) 2) If you lose 1 of the 3 above, then you no longer can determine the correct time 3) Therefore with 4, you have redundancy.
We have two Symmetricom Stratum 1 time servers synced via GPS with Rubidium oscillators, and two RHEL 6 servers running ntpd for our 4 servers.
Having a number of NTP servers will help you detect false tickers which may be critical. If you want something that is "cheap" as in you for your home, I can recommend this: ~$350 w/ antenna, etc.. http://www.netburnerstore.com/product_p/pk70ex-ntp.htm You can get the whole thing going quickly. Majdi has also had good luck with this unit (perhaps he wants to chime-in, heh pun unintended) regarding a few other devices. If you ask politely off-list, I will point you at where one of these is that you can talk to (in Dallas at the Infomart for your low-latency config). - Jared