On 2017-05-09 01:45, ashu6...@gmail.com wrote: > How can we add redundant server into NTP 4.2.8p10 ? If we try to > edit the configuration file it's not switching to the redundant > server?
After changing the /etc/ntp.conf file, you need to restart any server ntp daemon using it to put changes into effect. When dealing with ntp, patience is often required, to see if changes have any obvious effect. If you have insufficient truechimer sources (3, 5, ...) to form a *majority* clique, the time will not be updated, as if you had no sources. The ntpd daemon looks at the time provided by all upstream sources using its algorithms and calculates the correctness interval of the majority clique survivors using averages weighted by the normalised reciprocal root distance to give the smallest maximum error in both offset and jitter. If the survivor source with the smallest root distance (and thus smallest maximum error), the candidate source, is not the same as the previous system source and the offset difference between the candidate source and the previous system source is less than the clockhop threshold (initially 1ms), the system source stays the same and the clockhop threshold is halved, so it could take more than one poll interval to replace the system source if offsets are very similar. These values are updated every time another packet is received from any upstream source and passes sanity checks, or the system source is unreachable after eight poll intervals. This could take 128s (~2min) for LAN sources with minpoll 4, or 512s (~8min) for network sources with minpoll 6; except at startup with sources using iburst, when six packets are sent at poll 1 (2s intervals), or after operating for a long period, with network sources at default maxpoll 10/1024s, when it could take ~136min to become unreachable. For more details see: https://www.eecis.udel.edu/~mills/ntp/html/prefer.html#clockhop and linked/related pages. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions