[dns-operations] Reverse Lookup speedup

[Paul Vixie]

this isn't bind-users at isc.org.  bind discussions should go there.  this is
dns-operations@, an implementation independent mailing list.  so i'll keep
this brief.

> > 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.

the only reasons to restart bind are if it's anally compacted (out of memory)
or if you're changing server binaries (upgrading).  otherwise, use reconfig,
which does not, repeat not, empty the cache, but will pick up any config file
changes (new zones, dropped zones, option changes) you've made lately.

> 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?

not.