On 2010-11-13, Harry <simonsha...@gmail.com> wrote: > On Nov 13, 3:39 pm, David Woolley <da...@ex.djwhome.demon.invalid> > wrote: > >> Harry wrote: >> >> > server 2.asia.pool.ntp.org I assume, then, that adding a couple >> > more entries should address the "4 or more" tip of yours and >> > provide me a stable and accurate time... enough to not necessitate >> > the need for an MD5 authentication. Chuck >> >> If you need a high level of trust, you should be using hand picked >> servers (as you would have to if you were using authentication). > > ... how would I find out which servers to highly trust and > which ones to not?
You may want to give weight to servers run by organizations you trust. You should examine your potential servers (with ntpq -p) and see what their time sources are. Choose servers from the Stratum 2 Public Time Server List at http://support.ntp.org/s2. If you are supporting a large client population you may choose from the Stratum 1 Public Time Server List; see http://support.ntp.org/rules for more information. If your requirements are high consider chosing more than you will ultimately use and then prune the list after you see which are more reliable/stable. > Are any graphs or other stats on the past history of a given server > available? These could include the server's uptime, its deviation > (amount of dev, frequency of dev,...) compared to the majority > of others in its pool (or, relative to another arbitrary server > (/usr/bin/ diff like capability)) , etc. There are stats available for Pool Servers. But you're not supposed to "cherry pick" from the Pool. > The remote ntpd (of the server) already must be constantly building/ > updating some such knowledge in its internal memory structures. If > yes, any way to make it dump such knowledge, say, to stdout (or to the > log) of the client? ntpd only retains information about the last 8 samples. For more detail you need to see the server's peerstats and loopstats files. -- Steve Kostecke <koste...@ntp.org> NTP Public Services Project - http://support.ntp.org/ _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
