Linux: DNS on the device

Linux has no single DNS screen, but the two most common paths cover almost every computer: the network settings (NetworkManager, the easiest) or systemd-resolved with encrypted DNS. If the computer is on your home Wi-Fi and the router is already set up, it is covered already.

1. The easiest: network settings (Ubuntu, Mint, Fedora)

This sets the free filter's addresses for the whole computer. It blocks adult content, but does not apply a child's own rules (bedtime, apps) — for those, use step 2 or the router.

1. Open Settings → Network (or Wi-Fi) and click the gear next to your connection.
2. Choose the IPv4 tab and turn Automatic off next to DNS.
3. Enter 1.1.1.3, 1.0.0.3 in the DNS field.
4. Do the same on the IPv6 tab with 2606:4700:4700::1113, 2606:4700:4700::1003 if the field is there.
5. Save, then switch the Wi-Fi off and on again. Test at Is it working?.

2. Encrypted, with your own rules: systemd-resolved

On a paid plan every device gets its own DNS-over-TLS name (on the dashboard under the device's setup). As an administrator, create the file /etc/systemd/resolved.conf.d/dieratel.conf with this content, using your device's own name instead of the example:

[Resolve]
DNS=34.35.143.112#your-device-name.dot.dieratel.com 34.35.128.55#your-device-name.dot.dieratel.com
DNSOverTLS=yes

Then run sudo systemctl restart systemd-resolved. For the free Family filter without your own rules, use 1.1.1.3#family.cloudflare-dns.com as the DNS line.

3. Keep it in place

Give a child a standard account without sudo rights, so the settings cannot be changed. Browsers can slip past the system DNS with their own secure DNS: point it at Die Ratel or turn it off (see browsers).

Check that it works