Hostname resolve fails after upgrade from 4.2 to 4.5

Guru Prasad gp22online at
Thu May 11 19:11:52 UTC 2017

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


On May 12, 2017 12:34 AM, "Guru Prasad" <gp22online at> wrote:

> Thank you very much for the explanation Uri.
> Thanks
> Guru
> On May 12, 2017 12:13 AM, "Uri Simchoni" <uri at> 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
>> >

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