resolv.confの手動設定 - RedHat

NetworkManagerの無効化

 cd /etc/NetworkManager/conf.d/
 sudo touch 90-dns-none.conf
 sudo vi 90-dns-none.conf
 --------------
 [main]
 dns=none
 --------------

NetworkManagerのリロード

 sudo systemctl reload NetworkManager

/etc/resolv.confの作成（修正）

 sudo vi /etc/resov.conf
 --------------
 nameserver 8.8.8.8
 --------------

参考

https://access.redhat.com/documentation/ja-jp/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/manually-configuring-the-etc-resolv-conf-file_configuring-and-managing-networking