> -----Mensagem original----- > De: Nuno Pereira Em > nome de William Unruh > Enviada: sexta-feira, 20 de Fevereiro de 2015 23:59 > Para: questions@lists.ntp.org > Assunto: Re: [ntp:questions] NTP with 2 servers > > On 2015-02-20, Nuno Pereira wrote: > > > > > > > > In our infrastructure we had some ntp clients that don't have access to the > > world and so they are configured to use only 2 servers (by the way, the other > > have 2 more options). In reality both servers are the same, but with different > > IPs. > > So you only have one server. Why have two that are the same? Short answer: for historical reasons. Long answer: we considered that we needed one more server in our infrastructure (remember that most of our network has 2 more sources, external), and so we designated an IP for that. We didn't had a good alternative as a server to be that second ntp server, and so we added that IP to the current ntp server and configured it in our clients. Months had passed since then, and we still didn't designate that second server.
By the answers that I've received meanwhile, we need 2 more. > > From time to time some clients configured in this way lose their reference for > > some short period. > > > > > > > > I know how NTP works > > (http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#Q-NTP-ALGO), and so this > seems > > to be caused by both 2 servers or just 1 of them not have survived. > > > > But both the clients and the servers are physically in the same place, and > > even if they aren't in the same IP network, they are in the same LAN with just > > a switch or two between them (delay is between 1 and 2 ms). > > What is the switch? Smoke signals? Any switch should be a lot lot faster > than 1ms. I realized that, at least the server from where I took that value i salso behind a firewall. And a router to be in the middle isn't discardable. Is 0.2-0.3 a good value? That's what we have in some cases. > > And the question is why this does happen in the local network? > > > > Aren't they close enough in order to avoid a split? > > > > > > Given that, I have changed the configuration, and now they only use 1 server, > > but that is not a good solution. > > But that is what you have! That's true, and that's why I've sent this question. Nuno Pereira G9Telecom _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
