[Samba] Hostname resolve fails after upgrade from 4.2 to 4.5

[Andreas Schneider]

On Thursday, 11 May 2017 21:11:52 CEST Guru Prasad via samba-technical wrote:
> If the machine has samba 4.4 or above installed in it then any program such
> as ping sends a request to winbindd for name resolution.
> 
> Hope ping is a independent program and doesn't depend on samba or winbindd.
> Then how will the ping/mount request reaches winbindd from 4.4 and not
> before that.
> 
> Is there any specific rule for this in nsswitch conf or somewhere else.
> 
> Please bear with me in case if my questions troubles you in your busy
> schedule.

https://en.wikipedia.org/wiki/Name_Service_Switch
https://www.gnu.org/software/libc/manual/html_node/Name-Service-Switch.html

> 
> Thanks
> Guru
> 
> On May 12, 2017 12:34 AM, "Guru Prasad" <gp22online at gmail.com> wrote:
> > Thank you very much for the explanation Uri.
> > 
> > Thanks
> > Guru
> > 
> > On May 12, 2017 12:13 AM, "Uri Simchoni" <uri at samba.org> wrote:
> >> On 05/11/2017 09:33 PM, Guru Prasad wrote:
> >> > Thank you very much Uri.
> >> > It means winbindd handles netbios name resolution from samba 4.4.0.
> >> > Just to understand, before samba 4.4.0 under which process this netbios
> >> > name resolution  was handled?
> >> 
> >> It was under the process that called getaddrinfo() or any other glibc
> >> name resolution routine.
> >> 
> >> Glibc has a plugin mechanism (name service switch, or nsswitch for
> >> short) which loads plugins acording to /etc/nsswitch.conf. When a
> >> program (such as ping) calls getaddrinfo(), the glibc implementation
> >> loads those plugins and runs them according to the order and policy
> >> defined in /etc/nsswitch.conf.
> >> 
> >> Prior to 4.4.0, the wins plugin itself would send and receive netbios
> >> packets, from the context that called getaddrinfo() or any other such
> >> function. Since 4.4.0, it sends a request to winbindd (over a Unix
> >> domain socket) and awaits response.
> >> 
> >> Uri
> >> 
> >> > Thanks
> >> > Guru