dnsmasq

https://thekelleys.org.uk/dnsmasq/doc.html

/etc/dnsmasq.conf
server=/lab/172.16.3.6
server=<my-isp-dns>
server=1.1.1.1
bind-interfaces

/etc/resolv.conf 
search lab
nameserver 127.0.0.1

/etc/NetworkManager/NetworkManager.conf 
[main]
dns=none
rc-manager=unmanaged