[dns-operations] Reverse Lookup speedup

[Lutz Donnerhacke]

* Michael Monnerie wrote:
> On Donnerstag, 2. August 2007 Lutz Donnerhacke wrote:
>> I can tell you, that the in-addr.arpa and ip6.arpa entries are cached
>> on the recursive name servers, so that there is no performance benefit
>> in slaving those zones.
>
> This is for sure valid for a running bind, but after a restart all
> caches are emptied, right? We're currently in a big reconfiguration,
> so bind restarts happen more often than I would want. Having the
> .in-addr.arpa zone locally saves at least the 1st level lookups, thus
> helping after a restart, or isn't that worth the simple zone copy?

It's not worth the configuration. You will look up and cache the few dozen
entries in a few seconds. Remember ip-addr.arpa and ip6.arpa does benefit
from the hierarchical structure, which is perfect for caching. It's not a
broken second level domain with a large flat database.