[LEDE-DEV] busybox ntpd not syncing if any server is bad (update, if _first_ server is bad)

[Karl Palsson]

Final note here, busybox has fixed this upstream, and ntpd now
syncs faster and _vastly_ more reliably with bad servers in the
list. Depending on their release schedule some people may like
the patches backported, but I'm just carrying them myself for the
time being.

Cheers,
Karl P


Karl Palsson <karlp at tweak.net.au> wrote:
> 
> For a followup, on master, with busybox 1.27.2, busybox ntpd
> will sync with bad servers in the list, but only if they're not
> _first_ Further, "bad.example.org" won't count as "bad" for the
> purpose of these tests. Someone (presumably dnsmasq?) is
> responding instantly with failures there.
> 
> Try something like 
> /usr/sbin/ntpd -n -N -d -l -S /usr/sbin/ntpd-hotplug -p bad1.n
> otexample.notorg -p bad2.notexample.notorg -p
> good.working.server.here.com
> 
> It appears that the dns resolution times out, and is ordered in
> such a way that busybox sends a request, and even though it
> gets a reply "instantly" it doesn't actually process it for
> several seconds. At that point, it .. fails? to process
> properly, and so just continues sending requests, getting
> replies, and never stepping or setting the stratum. (And hence,
> my tests with ntpdate -q never succeeded)
> 
> I've filed https://bugs.busybox.net/show_bug.cgi?id=10466 with
> busybox for this. It's actually only a bother for me in my
> development environment, where the *.pool.ntp.org addresses
> aren't resolveable
> 
> Sincerely,
> Karl Palsson
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