Michael Deutschmann wrote: > I've noticed a conflict between the instructions on the NTP server Pool > project page and other NTP advice. > > It is commonly advised here to configure ntpd either to slave to 1 > server, or to track 4 or more. The reason being that, when not slaving > blindly to one server, NTP's algorithms require 3 good servers, and if you > know all three will remain good, you may as well blindly track one. > > In contrast, the NTP Pool directions explicitly say to use only 3 pool > servers when using the pool alone, and only 2 if you have a local > timeserver at your ISP. Presumably this also means only 1 pool server if > you have 2 others, and no pool servers if you have three or more others. > > The intersection of these two rules mean the only possible answer is to > use one pool server with no backup, or no pool servers at all. > > This means that the [012].*.pool.ntp.org hostnames are of no legitimate > use. > > > At present, I have my border NTP server slaved to my ISP's timeserver. > But that computer went nuts as of last Friday (It's in an endless loop > cycle of about twenty minutes -- it keeps letting the offsets to it's > reference servers drift to -2.8s and then resetting itself.), so I'm > considering adding the pool as a fallback. But following all the rules, > this is impossible. > There's no requirement that you only use NTP servers from the pool. I don't use them at all. The pool people may not want you to use too many of the servers but that is a different matter altogether.
Danny _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
