resolv.conf file

Do not worry for the comment after the # sign that states “Generated by NetworkManager” that was valid before we disabled DHCP on our CentOS 7 machine, since then our server uses an static IP address and also static or manually configured DNS settings.

resolv.conf file settings

It is quite common that the Network Manager overwitte the DNS settings, if that is your case then follow the steps listed in this article.

Where to go next?