[Samba] After upgrade to 4.9.4, internal DNS no longer working

[Viktor Trojanovic]

Hi Louis,

I agree, it's unlikely an issue with Samba per se. As I described, I have a
second server (in another domain) that is set up almost identically, and it
all works there properly. The only difference there is that I did more
interim upgrades than I did on this system we speak about now.

As I mentioned, I have already shared the information you asked for but I'm
happy to compile it once more. Here you go:

/etc/hostname
--------------------
DC1

# hostnamectl --static ==> DC1
# hostnamectl --transient ==> DC1

/etc/hosts
--------------
127.0.0.1        localhost.localdomain    localhost
192.168.1.1        dc1.samdom.example.com    dc1

/etc/nsswitch.conf
------------------------
passwd: files winbind mymachines systemd
group: files winbind mymachines systemd
shadow: files
publickey: files
#hosts: files mymachines myhostname resolve [!UNAVAIL=return] dns
hosts: files dns
networks: files
protocols: files
services: files
ethers: files
rpc: files

(Note: This file looked slightly different before I went on with the
upgrade but I didn't keep a copy of the previous version. I believe I just
added "mymachines systemd" and "mymachines myhostname resolve [..]" in the
respective lines. After chatting with Rowland, I changed the "hosts" line
back to how it looks now and how it most likely looked before. However,
this had no impact on the described issues.)

# systemctl stop systemd-resolved
# systemctl disable systemd-resolved

 /etc/resolv.conf
----------------------
nameserver 192.168.1.1
search samdom.example.com

And yes, systemd-resolved was active and DNSStubListener was not disabled.
However, as explained, I have a "twin" system that is almost identical,
with Samba 4.9.4, and with systemd-resolved fully active, and it all works
without issues. So this can't have been the reason for the errors.

And just fyi, I checked the logs of this twin system and the lines about
"libreplace-samba4.so" not being found are there too. Since everything
works on that system, I guess this error message can actually be ignored.
Though I will raise it with the package maintainer at Arch, maybe there is
an error there. So, at the end of it all, I still have no clarity why
4.9.4. didn't want to work. But I'm just glad to have the AD back.



On Thu, 27 Dec 2018 at 16:11, L.P.H. van Belle via samba <
samba at lists.samba.org> wrote:

> Hai Viktor,
>
> Yes, i did keep that in mind that it was an upgrade, that exact why im
> responding. ;-)
>
> If in the base  /etc/hostname, /etc/nsswitch.conf and /etc/resolv.conf or
> systemd  cointains wrong settings, you might inherit these.
> So it might be that a previous samba was accepting these settings, but a
> latest samba not.
> Or a previous systemd version accepted these and a newer not..
>
> Setting : DNSStubListener=No in /etc/systemd/resolved.conf.
> is correct also, yes, its what you preffer, i mask the needed services.
>
> >hostname is DC1, confirmed by hostnamectl, resolv.conf has just two
> entries: nameserver (own IP), and search samdom.example.com. Same as it
> is now, so this all works.
> Just that because it works, that does not tell you if its correct.
>
>
> I dont expect that this problem is a samba problem, because we would have
> seen moch more messages.
> i still say, the upgrade problem is due your setup.  ( sorry )
>
> Now, if you going to upgrade, i suggest review you setup closely.
> And keep Rowland and my advice in mind.
>
>
> Greetz,
>
> Louis
>
>
>
>
>
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