Maarten Wiltink wrote: > Spoon wrote: > >> Consider a cluster of computers on a LAN. These computers have no >> acess to a reference clock (no Internet, no GPS, etc). >> >> One could still want to have all their clocks synchronized, even if >> this means they are all slowly drifting away from the "real" time. >> >> I've read a FAQ which seems to describe this use case. >> http://www.ntp.org/ntpfaq/NTP-s-refclk.htm#AEN4264 >> >> All I need to do would be to add these lines: >> >> server 127.127.1.1 # LCL, local clock >> fudge 127.127.1.1 stratum 12 # increase stratum >> >> to my configuration file? Did I understand correctly? > > It would work, most likely. > > You'd be following a single server's eccentricities, though, and there > are two cases where this could be bad. First, if you've chosen a server > that wanders around rather a lot (say, next to a door), your entire > network will get time that also wanders around a lot. Not a very big > deal, usually.
When you say that the clock in a server next to a door will wander a lot, are you referring to the effects of the sudden temperature swing when a cold draft comes in the server room? > The other potential problem is that there is a maximum drift that can be > corrected. If the difference between your server and any other host is > larger than that, the client won't be able to follow the server, while > both would be able to follow UTC. This is unlikely but possible. I was wondering whether it is possible to reduce the maximum rate of change? Is that what the tinker dispersion option is for? http://www.ee.udel.edu/~mills/ntp/html/miscopt.html "The argument becomes the new value for the dispersion increase rate, normally .000015 s/s." Does this mean that the maximum rate of change is 15 µs per second? Could I safely change this value to 5 µs per second? > Orphan mode may be better. It's in the docs, too. Found it. http://www.ee.udel.edu/~mills/ntp/html/manyopt.html#orphan Thanks for the pointer. I will read it carefully. Regards. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
