[ntp:questions] long time to report sync per leap indicator, when initial system time is set far into the future

Stephan E. public-se at innominate.com
Mon Dec 11 11:49:44 UTC 2017


I want ntpd 4.2.8p10 to sync to public servers, then serve time to a local network. It is running with '-g' because initial system time on the host can be far off. I observe that, when initial system time of the host was set > 5 minutes into the future, the time it will take ntpd to report a synced leap second to its clients approaches the time of that initial offset. E.g., when the initial time was erroneously set 24 hours into the future, ntpd will take approximately 24 hours to report a synced time in the LI field to its clients, and they will reject to sync to my host during that period.

Is this behavior to be expected, or is it likely that am I doing something wrong? I would agree that it is a weird scenario, but it can not be ruled out in my application.

A workaround appears to be running with '-g -q' first, in which case ntpd will sync and exit under 1 minute; then run without either option, in which case the LI field will report a sync within approx. 300s.

Do you think the workaround is suitable, or am I inviting e.g. errors in leap second handling?


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