samba - May 2018 - Help, DNS forwarding not working!

Hi list,

Today, DNS forwarding stopped working for my domain, and I have no clue 
as to why. We are using Samba internal DNS.

It stopped working for one DC on old hardware a couple of days ago. I 
suspected a hard drive issue (bad blocks in DNS related files) and 
wanted to replace the server in the next days.

Today I rebooted the other DC due to maintenance of the host machine, 
and DNS forwarding stopped working there as well.

I am puzzled as everything else seems to be working fine (Windows 
log-ons, file access on a member server).

Where can I look, what can I do?

Please help. This domain is in production and we basically don't have 
any internet now.

Thanks,
Ole

On Tue, 29 May 2018 13:40:50 +0200
Ole Traupe via samba <samba at lists.samba.org> wrote:
> Hi list,
> 
> Today, DNS forwarding stopped working for my domain, and I have no
> clue as to why. We are using Samba internal DNS.
> 
> It stopped working for one DC on old hardware a couple of days ago. I 
> suspected a hard drive issue (bad blocks in DNS related files) and 
> wanted to replace the server in the next days.
> 
> Today I rebooted the other DC due to maintenance of the host machine, 
> and DNS forwarding stopped working there as well.
> 
> I am puzzled as everything else seems to be working fine (Windows 
> log-ons, file access on a member server).
> 
> Where can I look, what can I do?
> 
> Please help. This domain is in production and we basically don't have 
> any internet now.
> 
> Thanks,
> Ole
> 
> 
> 
First post your smb.conf
Can you ping the forwarder from the DC ?
Is anything listening on port 53 on the DC ?
Is anything listening on port 53 on the DC that shouldn't be ?
OS ?
Samba version ?

Rowland

Please ignore, resolved now (although I don't know why or how). Strange 
that things always resolve only after (!) posting to this list. The 
latter seems to work in magic ways. ;)

Rowland, thank you very much for your quick replay!! I was able to ping 
the forwarder, but i wasn't able to resolve any hostnames on the DCs 
themselves. After I restarted the samba services, the issue went away. I 
did some changes to the smb.conf and only applied them via "smbcontrol 
all reload-config". Seems that a complete service restart was necessary 
for whatever reason.

Thanks again!
Ole


On 29.05.2018 13:59, Rowland Penny via samba wrote:
> On Tue, 29 May 2018 13:40:50 +0200
> Ole Traupe via samba <samba at lists.samba.org> wrote:
>
>> Hi list,
>>
>> Today, DNS forwarding stopped working for my domain, and I have no
>> clue as to why. We are using Samba internal DNS.
>>
>> It stopped working for one DC on old hardware a couple of days ago. I
>> suspected a hard drive issue (bad blocks in DNS related files) and
>> wanted to replace the server in the next days.
>>
>> Today I rebooted the other DC due to maintenance of the host machine,
>> and DNS forwarding stopped working there as well.
>>
>> I am puzzled as everything else seems to be working fine (Windows
>> log-ons, file access on a member server).
>>
>> Where can I look, what can I do?
>>
>> Please help. This domain is in production and we basically don't
have
>> any internet now.
>>
>> Thanks,
>> Ole
>>
>>
>>
> First post your smb.conf
> Can you ping the forwarder from the DC ?
> Is anything listening on port 53 on the DC ?
> Is anything listening on port 53 on the DC that shouldn't be ?
> OS ?
> Samba version ?
>
> Rowland
>