[Samba] [samba] file server, AD client, no rfc2307

mathias dufresne infractory at gmail.com
Thu Aug 3 12:53:37 UTC 2017

2017-07-27 16:33 GMT+02:00 mathias dufresne <infractory at gmail.com>:

> 2017-07-27 15:14 GMT+02:00 Rowland Penny via samba <samba at lists.samba.org>
> :
>> On Thu, 27 Jul 2017 08:51:52 +0100
>> Rowland Penny via samba <samba at lists.samba.org> wrote:
>> > On Thu, 27 Jul 2017 08:36:51 +0100
>> > Rowland Penny via samba <samba at lists.samba.org> wrote:
>> >
>> > >
>> > > I will have a look at the provision code for the Samba DC to see
>> > > what it actually does when you use '--use-rfc2307', if it just adds
>> > > 'ypServ30.ldif', I will setup a test domain without '--use-rfc2307'
>> > > and see what happens ;-)
>> > >
>> > > Rowland
>> > >
>> >
>> > OK, '--use-rfc2307' adds 'idmap_ldb:use rfc2307 = yes' to smb.conf on
>> > the DC and then adds 'ypServ30.ldif'. As far as I am aware, nothing
>> > actually uses anything in 'ypServ30.ldif'.
>> >
>> > I will set up a new domain and see what happens.
>> >
>> > Rowland
>> >
>> >
>> OK, I can now confirm that you do not need '--use-rfc2307' to use the
>> winbind 'ad' backend on a Unix domain member.
>> You do need 'idmap_ldb:use rfc2307 = yes' in the smb.conf on a DC to
>> use uidNumber & gidNumber attributes on the DC.
>> You will not be able to use ADUC without '--use-rfc2307'
> Nice, thank you for testing. I'll try that next days to first be sure of
> the winbind client configuration.
> Then I will have to test the working configuration against MS AD as it is
> MS AD my client use. It won't be my client too long...

Hi all,

I'm digging up that subject as I finally was able to find time to dig into
the subject.

So I first configure a file server using Winbind to retrieve user from AD
using RFC2307.

The tests :
Initially that file server was joined to a Samba AD domain with RFC2307 set
up on DC (--with-rfc2307 during provision).
No surprise, it worked.

Then I removed RFC2307 using ldapmodify to delete 55 entries added by
ypServ30.ldif which is the file used to add RFC2307 in Samba when it was
provisioned without --with-rfc2307 (as described there:
Here again, after "net ads leave" then a join into that domain, winbind was
able to retrieve AD user using RFC2307 LDAP attributes, as long as I kept
into into DC's smb.conf the following line as mentioned in previous mail by
Rowland the 27th of July:
idmap_ldb:use rfc2307 = yes

As I wasn't too sure about this modification (ldapmodify to delete entries)
I tried using a brand new Samba AD domain provioned without usage of
Again, it worked, as long as the "idmap_ldb:use rfc2307 = yes" xwas present
in DC's smb.conf

And as soon as "idmap_ldb:use rfc2307 = yes" was commented on DC side,
winbind on client side stopped working.

Finally I removed that Samba file server from the Samba AD domain to join
it to the MS AD domain of my client. This is a MS AD without support for
RFC2307 configured.
And Winbind was never able to generate UNIX user.
wbinfo -n user gave user's SID
wbinfo -S <user's SID> gave user's uidNumber (as we are dealing with
RFC2307 attributes, using idmap-ad)

But wbinfo -i user didn't worked.

 wbinfo -i user
failed to call wbcGetpwnam: WBC_ERR_DOMAIN_NOT_FOUND
Could not get info for user user

So usage of "idmap_ldb:use rfc2307 = yes" on DC side modifies Samba AD
behaviour enough for it differs from standard MS AD (nothing to wonder
about in fact) but as Samba AD is not behaving like standard MS AD we can't
write winbind, using idmap-ad, can retrieve user from standard AD without
RFC2307 configured, as this works only against Samba AD with a modified

To write it differently winbind, using idmap-ad, can't retrieve user from
standard AD (MS AD not modified or Samba AD without "idmap_ldb:use rfc2307
= yes").

>> Rowland
>> --
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