Custom Local DNS with Ubuntu Clients

[Ralf Mardorf]

On Sun, 11 Mar 2018 13:33:03 -0400, Tom H wrote:
>On Sun, Mar 11, 2018 at 11:53 AM, Aero Maxx <aero.maxx.d at gmail.com>
>wrote:
>>
>> I have a single linux desktop client running Ubuntu, and have 2
>> physical servers that are on my network that providing DNS
>> resolution.
>>
>> I want the linux desktop to use the local servers for DNS resolution
>> only, but Ubuntu somehow keeps finding the DNS server that is in the
>> router/modem that my ISP has provided me with.
>>
>> Is there a way I can stop the IP address of my router from being
>> added to the /etc/resolv.conf file?
>>
>> I tried removing the resolvconf package, but this broke things as for
>> some reason I wasn't able to then create my own resolv.conf file.
>>
>> Thanks for any help you are able to give me.  
>
>What is the app that's managing the network? NM? ifupdown?
>systemd-networkd?
>
>Is resolvconf or systemd-resolved involved in setting up
>"/etc/resolv.conf"?
>
>What's the output of "ls -l /etc/resolv.conf" and
>"cat /etc/resolv.conf"?

What happens if you ensure that /etc/resolv.conf isn't a link, but an
immutable file? SICR