Ubuntu – Configure IP updater for OpenDNS

What do I need to configure to prevent localdomain from being added to the resolv.conf file?

First make sure that the resolvconf package is installed and that /etc/resolv.conf is a symbolic link to ../run/resolvconf/resolv.conf.

Second make sure that there are no domain or search lines in any of the files in /etc/resolvconf/resolv.conf.d/.

Third, find out where localdomain is coming from. If your interface is configured via DHCP then it's probably being sent by the DHCP server. Then fix the DHCP server configuration. If NetworkManager is involved, use the Connection Editor to make sure that localdomain is not in the Additional search domains field on the IPv4 Settings tab of any active connections.

Hello Saturne64 and welcome to Askubuntu! The contents of /etc/resolv.conf are ultimately overwritten, but we can still set your DNS server of choice for your computer through the Network Manager. Please follow these steps:

1. Click the wifi icon at the top-right of your screen and choose "Network Connections"
2. Click "Edit"
3. Click the "IPV4 Settings" tab
4. Next to "Method: ", click "Automatic (DHCP)" and choose "Automatic (DHCP) addresses only"
5. In the text box adjacent to "DNS Servers: ", type the address of your preferred DNS server.
6. Click "Save" and in a terminal, run sudo systemctl restart network-manager.service.

Let me know if you need further assistance :)