DNS サーバーの設定方法（nmcli）
まず現在の接続名を確認：
nmcli connection show
例として接続名が Wired connection 1 だった場合：
nmcli connection modify "Wired connection 1" ipv4.dns "1.1.1.1 8.8.8.8 9.9.9.9" nmcli connection modify "Wired connection 1" ipv4.ignore-auto-dns yes nmcli connection modify "Wired connection 1" ipv6.dns "2606:4700:4700::1111 2001:4860:4860::8888 2620:fe::fe" nmcli connection modify "Wired connection 1" ipv6.ignore-auto-dns yes nmcli connection up "Wired connection 1"
確認
nmcli connection show "Wired connection 1" | grep dns
Public DNS
1. Cloudflare（1.1.1.1 / 2606:4700:4700::1111）
2. Google（8.8.8.8 / 2001:4860:4860::8888）
3. Quad9（9.9.9.9 / 2620:fe::fe）