DNS Manager

The DNS Manager in Modularitea allows you to change your system’s DNS (Domain Name System) provider through a simple graphical interface. This guide explains what DNS is, why you might want to change it, and how to do so.

What Is DNS?

DNS (Domain Name System) is the internet’s phone book. When you type a website address like google.com into your browser, your computer needs to find the actual IP address of that server (e.g., 142.250.185.14). DNS is the system that performs this translation.

By default, your computer uses the DNS servers provided by your Internet Service Provider (ISP). However, there are several reasons you might want to use a different DNS provider.

Why Change DNS?

Available DNS Providers

Modularitea includes the following pre-configured DNS providers:

Cloudflare (1.1.1.1)

Cloudflare DNS is widely regarded as the fastest public DNS service. It is a strong choice for users who prioritize both speed and privacy.

Google DNS (8.8.8.8)

Google DNS is one of the most well-known public DNS services, offering excellent reliability and global coverage.

Quad9 (9.9.9.9)

Quad9 blocks access to known malicious domains using threat intelligence feeds. It is the best choice for security-focused users.

OpenDNS (208.67.222.222)

OpenDNS (by Cisco) offers optional content filtering features, making it popular for family and educational environments.

AdGuard (94.140.14.14)

AdGuard DNS blocks ads, trackers, and known malicious domains at the DNS level, providing system-wide ad blocking without installing a browser extension.

How to Change DNS

Step-by-Step

1. Open Modularitea.
2. Click the Settings button (⚙️) at the bottom of the sidebar.
3. Locate the DNS Configuration card in the settings grid.
4. The card displays your current DNS provider (if one of the supported providers is detected).
5. Select a new provider from the dropdown menu.
6. A PolicyKit authentication dialog will appear — enter your administrator password.
7. Wait for the confirmation notification.
8. Your DNS is now changed.

Verifying the Change

After changing your DNS, you can verify the change by running:

cat /etc/resolv.conf

You should see the nameserver entries for your selected provider. For example, if you selected Cloudflare:

nameserver 1.1.1.1
nameserver 1.0.0.1

You can also test DNS resolution speed:

dig google.com

The Query time in the output indicates how fast your DNS resolved the query.

Technical Details

How It Works

When you change the DNS provider through Modularitea:

1. The GUI calls the Tauri backend’s switch_dns command.
2. The backend invokes pkexec modularitea-dns-changer <provider>.
3. The modularitea-dns-changer binary (from tealinux-modularitea-libs) runs with root privileges.
4. It modifies /etc/resolv.conf to contain the selected provider’s nameservers.
5. The binary outputs a JSON result indicating success or failure.
6. The GUI displays the appropriate notification.

Why Administrator Password Is Required

Changing DNS requires modifying /etc/resolv.conf, which is a system file owned by root. The pkexec tool (part of PolicyKit) provides a secure way to run a specific command as root without giving the entire application root access.

Note: The pkexec dialog is a system-level authentication prompt. Modularitea never sees or stores your password — it is handled entirely by PolicyKit.

Reverting DNS Changes

To revert to your ISP’s default DNS:

1. Open a terminal.
2. Remove the custom DNS entries:

sudo rm /etc/resolv.conf

3. Restart the NetworkManager service to regenerate the file with your ISP’s DNS:

sudo systemctl restart NetworkManager

Alternatively, you can switch to a different DNS provider in Modularitea’s settings at any time.