securd resources

How to Enable DoH in Firefox

DoH (IETF RFC8484) allows browsers to send DNS requests as normal-looking HTTPS traffic to special DoH-compatible DNS servers (called DoH resolvers).  These are the instructions how to enable DoH for Firefox browsers.

How to configure DoH through the Firefox Browser UI

  1. Click the menu button Menu and select Preferences.
  2. In the General panel, scroll down to Network Settings and click the Settings button.
  3. In the dialog box that opens, scroll down to Enable DNS over HTTPS.On: Select the Enable DNS over HTTPS checkbox. Select a provider or set up a custom provider. Off: Deselect the Enable DNS over HTTPS checkbox.
  4. Click the Use Provider drop-down under Enable DNS over HTTPS to select a provider.
  5. Change DNS Provider
  6. Add your Securd DOH URL (located in the Securd Portal at Virtual Sites).
  7. Click OK to save your changes and close the window.
how to setup DoH firefox

How to configure DoH with about:config (Advanced)


network.trr.boostrapAddress=Securd Primary DNS Address (located in the Securd Portal)

network.trr.custom_uri=Securd DOH URL (located in the Securd Portal at Virtual Sites)


network.trr.uri=Securd DOH URL (located in the Securd Portal at Virtual Sites)

network.trr.mode (

2: Use TRR first, and only if the name resolve fails use the native resolver as a fallback.

3: Only use TRR, never use the native resolver.

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