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How to Set Network DNS via Command Line Interface (CLI) on Linux

List the connections with:

nmcli device

Assume the active connection is Wired connection 1 on enp2s0, set DNS to 8.8.8.8 like this:

✅ Set DNS to 8.8.8.8 (NetworkManager / nmcli)

nmcli connection modify "Wired connection 1" ipv4.ignore-auto-dns yes
nmcli connection modify "Wired connection 1" ipv4.dns "8.8.8.8"

Apply the change:

nmcli connection down "Wired connection 1"
nmcli connection up "Wired connection 1"

🔍 Verify DNS is active

nmcli device show enp2s0 | grep DNS

You should see:

IP4.DNS[1]: 8.8.8.8

Or:

resolvectl status enp2s0

🧠 Notes (important on CachyOS / Arch)

  • ipv4.ignore-auto-dns yes prevents DHCP from overwriting your DNS
  • This survives reboot
  • Works cleanly with systemd-resolved (default on CachyOS)

➕ Optional: add fallback DNS

nmcli connection modify "Wired connection 1" ipv4.dns "8.8.8.8 1.1.1.1"

🔄 Roll back to DHCP DNS (if needed)

nmcli connection modify "Wired connection 1" ipv4.ignore-auto-dns no
nmcli connection modify "Wired connection 1" ipv4.dns ""
nmcli connection down "Wired connection 1"
nmcli connection up "Wired connection 1"