Unruh wrote: > Uwe Klein <[EMAIL PROTECTED]> writes: > >> Unruh wrote: >>> Yes, that is with reference to the road. Car three should thus completely >>> ignore the other two cars and use his speedometer. >>> >>> Ie, put up a GPS receiver with a PPS and use that as your time source, and >>> ignore all the other ntp time sources, except perhaps as sanity checks (eg >>> if you r speedometer breaks you should get to know about it by occasionally >>> looking at the other cars) > >> A)One GPS to each box or >> B) a single GPS with PPS line to all boxes? > > Whichever you want. Up to you. > >> A: >> Doesn't that impact reliability? > >> You add the failure probability of a GPS-unit to each Box >> where one failure will make the whole system fail. > > So, that is why ntp has backup servers. You have a single failure point > anyway-- the network. It goes down, and nothing can get the time. > <snip>
If the possibility of failure of your network or your internet connection worries you, you can use a modem and a telephone line as a backup! Or you can get a GPS receiver, WWV/WWVH/WWVB receiver or an atomic clock of your very own. Most sites don't bother because their requirements are not that tight. FWIW, a system that has been synchronized by NTP will tend to stay close to the correct time for a reasonable period of time as long as the environment does not change significantly. If the network fails AND the air conditioning fails you are in trouble! _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
