ashu6...@gmail.com wrote: > Hi david, > 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?
The NTP reference implementation (ntpd) does not use redundancy in the way you might expect. I.e., you can't configure a "master" and a "slave" time source and expect the client to use only the master and switch to the slave when the master becomes unavailable. Instead, you can configure several time sources, and ntpd periodically checks them all, uses some voting process to see which send the same, best, and most accurate time, and selects the "best" time source as so-called "system peer". The local system time adjustment is derived from the weighted time offset from the system peer plus some other time sources which provide similar accuracy. If the selected system peer becomes unavailable then the client ntpd discards it and selects a new one from the remaining time sources. Please note that configuring exactly 2 time sources is the worst you can do: if both time sources provide a slightly different time then the client ntpd is unable to determine which one provides the "right" time. Further reading: http://support.ntp.org/bin/view/Support/SelectingOffsiteNTPServers#Section_5.3.3. http://doc.ntp.org/current-stable/prefer.html http://doc.ntp.org/current-stable/cluster.html Regards, Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
