From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yann E. MORIN <yann.morin.1998@free.fr>
Date: Thu, 10 Jul 2014 23:18:05 +0200
Subject: [Buildroot] ping not working in a glibc based buildroot
In-Reply-To: <53BEA249.3020808@scalemp.com>
References: <20140710142322.188e88ed@free-electrons.com>
 <53BE887E.7070606@scalemp.com>
 <20140710145619.5925fa1b@free-electrons.com>
 <53BE8EF2.9000306@scalemp.com>
 <20140710153435.6b2ab536@free-electrons.com>
 <53BE97D3.5090009@scalemp.com>
 <20140710160659.18c3af57@free-electrons.com>
 <53BE9FA5.9070002@scalemp.com>
 <20140710161645.1ad0e468@free-electrons.com>
 <53BEA249.3020808@scalemp.com>
Message-ID: <20140710211805.GI28300@free.fr>
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To: buildroot@busybox.net

Eial, All,

On 2014-07-10 17:25 +0300, Eial Czerwacki spake thusly:
> On 07/10/2014 05:16 PM, Thomas Petazzoni wrote:
> > Dear Eial Czerwacki,
> >
> > On Thu, 10 Jul 2014 17:13:57 +0300, Eial Czerwacki wrote:
> >
> >> I've added libnss_dns-2.18.so to the img and libresolv.so and it seems
> >> to be working.
> >> the files are missing because I work in a kinda limited size.
> > So you removed them manually? I'd like to understand what happened, to
> > fix Buildroot if needed.
> >
> >> do I need the other libnss_*.so files?
> > By default, we only copy libnss_dns (to do DNS resolution) and
> > libnss_files (to do /etc/hosts based resolution), and we don't copy the
> > other libnss_* libraries, which are used for more advanced name
> > resolution that are generally not used on most embedded systems.
> >
> > See 'man nsswitch.conf' for more details.
> >
> > Best regards,
> >
> > Thomas
> I see, as I don't use /etc/hosts, I think I don't need libnss_files.

The NSS libraries are not used only to provide DNS resolving.

They are used to do any kind of name lookups:
  - IP <-> hostname mapping (as already mentioned),
  - UID <-> username mapping,
  - gid <-> group name mapping,
  - and a bunch more. See the complete list:  man nsswitch.conf

Regards,
Yann E. MORIN.

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