[ntp:questions] ntpd on dial up machine: no DNS resolving => giving up on all servers

Arno Wald arno.wald at netcologne.de
Sun Jun 7 09:24:50 UTC 2009


Harlan Stenn wrote:

> There is an option to have ntpd retry failed DNS lookups for "longer". 
> This is in ntp-dev however (which is about to become ntp-4.2.6).

It would be good if a retry for a lookup would be started in case of a new 
network interface is showing up, too.

Also if a ntp-server is no longer reachable it would be good to recheck the 
IP address. E.g. if you are using a ntp-server-pool name and retrieve a 
"random" IP address from this pool and the server is going offline after 
some days, it would be a good idea to retrieve a new IP address.

> Use IP numbers instead of names.

I do not like to hard wire IP addresses in configs. It is less robust IMHO. 
Also you drop the functionality of using server-pools.

> Get a reasonably inexpensive GPS device and use that for time (or if
> geographically convenient, one of the radio refclocks).

This is a nice idea. But maybe it is a little bit oversized for just a 
simple working PC? But I keept it in mind.

> You really only want to prevent ntpd from stepping the time backwards.

Yes, right.

Thanks,
Arno





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