On Thu, 2008-05-08 at 08:00 -0500, Ryan Malayter wrote: > On Wed, May 7, 2008 at 11:39 PM, Eugene Smiley <[EMAIL PROTECTED]> wrote: > > You need more commonality between the two servers configs. Currently, your > > only > > commonality is a server that has a high delay (aka network-wise distant from > > you). At least put time.nist.gov in both configs and note the difference. > > For what it's worth, I would recommend against time.nist.gov unless > you have some sort of regulatory requirement that it be used. It is > under very heavy load, as are the other NIST and USNO servers.
I am using (on Blue): server ntp.ubuntu.com server 0.us.pool.ntp.org server 1.us.pool.ntp.org server 2.us.pool.ntp.org server 3.us.pool.ntp.org Blue got time.nist.gov as part of the draw. When I reboot, it will be a different group. I did not select it. ntp.ubuntu.com was the default one that came with the distribution, so I decided to keep it, even though I think it is in Europe. > > All of those show very jittery time from my network vantage point, > undoubtedly due to network traffic. I recall a recall reading that > USNO handles >5 Mb/s of NTP traffic, and that was many years ago. It > may be much worse than that now. Also the typical "rules of > engagement" are that you never use a stratum-1 unless you are a > stratum-2 server that is in turn serving time to many clients. > I have Verizon FiOs 2 MB up and 5 MB down. I do not know if that makes a difference on the jitter. I would hope it made it better. > In your situation, if you really have only these two machines, I would > add use this configuration on blue: > server 0.pool.ntp.org > server 1.pool.ntp.org > server 2.pool.ntp.org > server 3.pool.ntp.org > > And this configuration on red: > server blue iburst prefer > server 0.pool.ntp.org > server 1.pool.ntp.org > server 2.pool.ntp.org > > This ensures that red syncs to blue, but uses the NTP pool as a sanity > check on its time. If blue really goes crazy and is marked as a > false-ticker, red will choose one of the pool servers as its source. > That is what I want. What is iburst? It is not listed in the server commands as an option. http://www.eecis.udel.edu/~mills/ntp/html/clockopt.html#server Reference Clock Commands server 127.127.t.u [prefer] [mode int] [minpoll int] [maxpoll int] This command can be used to configure reference clocks in special ways. The options are interpreted as follows: prefer Marks the reference clock as preferred. All other things being equal, this host will be chosen for synchronization among a set of correctly operating hosts. See the Mitigation Rules and the prefer Keyword page for further information. mode int Specifies a mode number which is interpreted in a device-specific fashion. For instance, it selects a dialing protocol in the ACTS driver and a device subtype in the parse drivers. minpoll int maxpoll int These options specify the minimum and maximum polling interval for reference clock messages in seconds, interpreted as dual logarithms (2 ^ x). For most directly connected reference clocks, both minpoll and maxpoll default to 6 (2^16 = 64 s). For modem reference clocks, minpoll defaults to 10 (2^10 = 1024 s = 17.1 m) and maxpoll defaults to 14 (2^14 = 16384 s = 4.5 h). The allowable range is 4 (16 s) to 17 (36.4 h) inclusive. Thanks Kip -- Kipton Moravec KE5NGX "Always do right; this will gratify some people and astonish the rest." --Mark Twain _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
