[Samba] AD DC DNS question

[Rowland penny]

On 16/09/2020 01:19, Jonathan Kreider via samba wrote:
> OS = Ubuntu 18.04 in an LXD container
> Samba 4.11.x and up
>
> Is there a way to have DNS resolution on the server that can coexist with
> the samba ad dc internal DNS server? The way that I have it set up,
> whenever samba is not running, then I can't use any web resources b/c
> everything goes through the samba internal DNS. So I can't do system
> updates and upgrades unless samba is running.
>
> I saw this discussion (
> https://lists.samba.org/archive/samba/2020-August/231345.html) between
> Louis and Rowland but didn't know if it might apply to my situation.
>
> ~# cat /etc/netplan/50-cloud-init.yaml
> # This file is generated from information provided by
> # the datasource.  Changes to it will not persist across an instance.
> # To disable cloud-init's network configuration capabilities, write a file
> # /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
> # network: {config: disabled}
> network:
>      version: 2
>      ethernets:
>          eth0:
>              dhcp4: false
>              addresses: [192.168.0.11/16]
>              gateway4: 192.168.0.200
>              nameservers:
>                  search: [mydom.samdom.com]
>                  addresses: [192.168.0.11, 192.168.0.14, 192.168.0.200]
>
> 192.168.0.11 is this server
> 192.168.0.14 is another AD DC
> 192.168.0.200 is a router/gateway
>
> Thanks,
> Jonathan Kreider

You can run as many dns servers as you like on a DC, they just cannot 
run on the same ipaddress and port. For example, if the DC's ipaddress 
is 192.168.1.2, the DC's internal dns server would be running on 
192.168.1.2:53, so you couldn't run another dns server on that IP/port, 
but you could run one on 192.168.1.3:53 and this would require another 
network device, real or virtual.

Of course, if you add another DC at any point, it all becomes moot, you 
would not be able to turn your DC's off as you would break replication.

Rowland