On Mon, Jun 25, 2012 at 11:02 PM, Ask Bjørn Hansen <[email protected]> wrote: > > On Jun 25, 2012, at 9:33, Dave Hart wrote: > >> iburst affects initial startup, plus re-acquisition if a server was >> unreachable. > > For any default configuration iburst is a bad idea. If you care enough about > the time you can add it, but distributors shouldn't include it by default.
With network sources at default minpoll 64s, it takes minutes to first sync the clock without iburst, a dozen seconds or so with iburst. Particularly for those taking the advice to ditch ntpdate-before-ntpd, it's quite reasonable and in fact comparable to ntpdate-then-ntpd. > Is it smart enough to only do the burst when the server is reachable again? > (And not as part of the "is it reachable now? now? or now?" checks). Yes. iburst only engages when a server reach goes from 0 to nonzero. burst applies every poll to which iburst doesn't. burst in a default config would be evil. iburst just makes sense IMO. If you're wondering where burst makes sense, an example is the modem (ACTS) driver polling every few hours or less frequently. Once the call is up, burst takes multiple samples. Similarly for a network source reached over a dial-on-demand link. Cheers, Dave Hart _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
