Ubuntu 20.04 Server remove local gateway from DNS Server

Question

Here is my setup :

 network:
 version: 2
 renderer: NetworkManager
 #renderer: networkd
 ethernets:
  enp2s0:
   dhcp4: yes
   addresses: []
   nameservers:
           addresses: [1.1.1.1, 1.0.0.1]
  enx28ee52061e61:
   dhcp4: yes
   addresses: []

systemd-resolve --status | grep 'DNS Servers' -A2

DNS Servers: 192.168.1.1
                  1.1.1.1
                  1.0.0.1

So every domain is resolved from 192.168.1.1 (router-gateway IP).

How can i remove it and all domains resolved from "1.1.1.1"?

cat /etc/resolv.conf

nameserver 192.168.1.1
nameserver 1.1.1.1
nameserver 1.0.0.1
# Too many DNS servers configured, the following entries may be ignored.
nameserver fe80::1%2
search home

cat /etc/systemd/resolved.conf

[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#DNSOverTLS=no
#Cache=no-negative
#DNSStubListener=yes
#ReadEtcHosts=yes

score 1 · Answer 1 · answered May 26 '23 at 15:38

This has been answered here https://askubuntu.com/a/1084736/993552

Basically in your /etc/netplan/filename.yaml add

dhcp4-overrides:
  use-dns: no

sudo netplan apply #do this after changing config

This will ensure whatever DNS nameservers come from DHCP will not be used by your link (ethernet or whatever network connection you change settings in)

Example

network:
  ethernets:
    ens5:
        dhcp4: true
        dhcp4-overrides:
            use-dns: no
        dhcp6: false
        set-name: ens5
        nameservers:
            addresses: [8.8.8.8, 4.4.4.4]
version: 2

Ubuntu 20.04 Server remove local gateway from DNS Server

1 Answers1