====== Disable DNS Caching on Ubuntu ======
Disable the systemd-resolved service and stop it:
<file>
sudo systemctl disable systemd-resolved.service
sudo service systemd-resolved stop
</file>
Put the following line in the [main] section of your **/etc/NetworkManager/NetworkManager.conf**:
<file /etc/NetworkManager/NetworkManager.conf>
...
[main]
dns=default
...
</file>
Delete the symlink /etc/resolv.conf
<file>
rm /etc/resolv.conf
</file>
**create new /etc/resolv.conf**
<file>
vim /etc/resolv.conf
</file>
Restart network-manager
<file>
sudo service network-manager restart
</file>
OR
<file>
sudo systemctl restart NetworkManager.service
</file>