Hi RubberDucky, what's the specific error message you get when Firefox can't connect to anything?

Are you enabling DNS over HTTPS through the Preferences page, or are you manually modifying settings in about:config? If you are manually modifying one or more settings, what values are you using?

The reason I ask that is Firefox has multiple modes for DNS over HTTPS, and some will "fall back" to the standard method of looking up addresses when they can't reach the "trusted resolver" and some will not (and therefore must fail). By default, enabling DNS over HTTPS through the Preferences page sets network.trr.mode = 2, which allows fallback. If you manually set network.trr.mode = 3, then you likely will need to also set network.trr.bootstrapAddress in order to allow Firefox to look up the address of the trusted resolver.

jscher2000 said

Hi RubberDucky, what's the specific error message you get when Firefox can't connect to anything? Are you enabling DNS over HTTPS through the Preferences page, or are you manually modifying settings in about:config? If you are manually modifying one or more settings, what values are you using?

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The reason I ask that is Firefox has multiple modes for DNS over HTTPS, and some will "fall back" to the standard method of looking up addresses when they can't reach the "trusted resolver" and some will not (and therefore must fail). By default, enabling DNS over HTTPS through the Preferences page sets network.trr.mode = 2, which allows fallback. If you manually set network.trr.mode = 3, then you likely will need to also set network.trr.bootstrapAddress in order to allow Firefox to look up the address of the trusted resolver.

Would I put cloudflares dns address in the network.trr.bootstrapAddress ?

I enabled dns over https in the options page.

And this is the error I get:

RubberDucky said

Would I put cloudflares dns address in the network.trr.bootstrapAddress ? I enabled dns over https in the options page.

If you enable DNS over HTTPS using the Options page, then you should find the value set to 2 here:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste trr and pause while the list is filtered

(3) If the network.trr.mode preference is not set to 2 you can double-click it to edit the value to 2 and then click OK

If network.trr.mode is set to 3 then the bootstrap address will depend on which resolver you use. For Cloudflare, I think the bootstrap address is 1.1.1.1 so you could try that.

By the way, some network administrators might block DNS over HTTPS because it interferes with their filtering. On one of those networks, you'll need to use normal address resolution.