[Samba] Samba and dnsmasq

[Robert Marcano]

On 12/18/18 4:09 PM, Rowland Penny via samba wrote:
> On Wed, 19 Dec 2018 06:28:54 +1100
> Nicolas via samba <samba at lists.samba.org> wrote:
> 
>> Hello everyone !
>>
>> Well, I'm setting up a 'new' box with samba 4.9.3 on Ubuntu 18.04
>>
>> Idea is to use Host OS for Domain Controler (dc1.smb.domain.tld) and
>> a LXC container (ubuntu 18.04 too) as Domain Member with File Server
>> (fs.smb.domain.tld).
>>
>> Administration through Windows OS will be done with a Qemu KVM.
>>
>> Bad thing is that I get :
>>
>>> Failed to bind to 0.0.0.0:53 TCP -
>>> NT_STATUS_ADDRESS_ALREADY_ASSOCIATED
>>
>> as dnsmasq is using port 53 :
>>
>>> netstat -tulpn | grep ":53"
>>> tcp        0      0 192.168.122.1:53 0.0.0.0:*
>>> LISTEN      1283/dnsmasq
>>> tcp        0      0 10.0.3.1:53 0.0.0.0:*               LISTEN
>>> 1062/dnsmasq
>>> tcp6       0      0 :::53 :::*                    LISTEN
>>> 1161/samba: task[dn
>>> udp        0      0 192.168.122.1:53
>>> 0.0.0.0:*                           1283/dnsmasq
>>> udp        0      0 10.0.3.1:53 0.0.0.0:*
>>> 1062/dnsmasq
>>> udp6       0      0 :::53 :::*
>>> 1161/samba: task[dn
>> Is there known solutions to resolve this, or should I use this kind
>> of method :
>>
>> https://medium.com/matematica-e-informatica/dnsmasq-and-samba4-ad-dc-74e69d46a1db
>>
>> Thanks in advance for your time.
>>
>> Nicolas
>>
>>
> 
> The best thing you can do is to:
> 
> apt-get remove dnsmasq
> 
> on the Samba AD DC.
> 
> You can run dnsmasq as a caching nameserver on the Unix clients, but
> the only supported Samba AD DC DNS servers are the Samba internal DNS
> server and Bind9, use of anything else is totally unsupported.

The dnsmasq process "1283/dnsmasq" looks like the default range 
(192.168.122.0/24) for providing DNS and DHCP for libvirt/KVM VMs, so it 
would not be possible to uninstall it, because it is a dependency of 
libvirt.

But that dnsmasq is not the one generating the ports collision, it is 
1062/dnsmasq, check with ps for example

   ps ww 1062

In order to see what configuration file is being used as an argument of 
that instance of dnsmasq and try to see what service used it.

Another tip is to use

bind interfaces only=yes
interfaces = $DC_PUBLIC_IP

for your Samba AD

> 
> Rowland
>   
>