[dns-operations] "best practices" for restaring internal DNS servers

Mark Andrews marka at isc.org
Sun Sep 9 21:38:20 UTC 2012

In message <BDDCE4FA-CEE9-466C-AB5C-9E3201BEFFB6 at nic.br>, Rubens Kuhl writes:
> > 
> > I'm not sure if I phrased my question correctly. It's not about
> > redundancy, but about keeping the queries to root/g(TLD) name servers
> > to a minimum.

Running without a cache at all makes a difference but starting a
caching nameserver has no real impact on the root servers or tld

> > In your example, if was the resolver that just came up again
> > after a restart, it wouldn't return a failure for a query that it has
> > not yet cached. Or perhaps I just didn't understand your answer.
> If your recursive DNS server runs Unbound, you can use
> unbound-control dump-cache > <filename> 
> prior to restarting
> and then
> unbound-control load-cache < <filename>
> I don't recall such an option being available with BIND 9, and it's 
> probably a feature to suggest to BIND 10. 

Unless you can show a significant benefit to the clients then it is
not worth the effort.  It doesn't take long for most of a cache to
timeout on disk.

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org

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