About root zones

[Barry Margolin]

In article <mailman.665.1325598835.68562.bind-users at lists.isc.org>,
 Matus UHLAR - fantomas <uhlar at fantomas.sk> wrote:

> >> On Jan 2, 2012, at 2:16 PM, Barry Margolin wrote:
> >> > If the system resolver is good enough for every other application
> >> > running on the system, it should be good enough for BIND.
> >> >
> >> > Why not at least allow this as an option?
> 
> >In article <mailman.656.1325532888.68562.bind-users at lists.isc.org>,
> > Chuck Swiger <cswiger at mac.com> wrote:
> >> The system resolver will happily provide answers based upon data from
> >> /etc/hosts, YP/NIS, and LDAP which have no relationship to what is in the
> >> DNS.
> 
> On 02.01.12 17:03, Barry Margolin wrote:
> >In that case, you probably shouldn't enable the option.  I'm not even
> >suggesting that the option be on by default.
> >
> >Actually, does libresolv really use those other facilities?
> 
> highly depends on configuration of host.conf or nsswitch.conf, but 
> afaik hosts are preferred by default on most of systems.
> 
> >gethostbyname() does, but BIND probably shouldn't use that, because it
> >loses data like TTLs.
> 
> and that is one of reasons why BIND does not (and apparently even 
> should not) use system libresolv and gethost* functions.

Are we talking about the same libresolv?  I'm talking about functions 
like res_query(), which are very DNS-specific.  They return the raw DNS 
reply data, including details like TTL.

gethostbyname() is the function that uses nsswitch.conf.

-- 
Barry Margolin
Arlington, MA