Firefox with ProtonVPN Extension leaks DNS - No leaks with windows app

VPN
1

Hello!

After searching this subreddit it seems like a problem that has been happening for a while and it even made me switch to Brave few months back (where the issue doesn’t happen), but now I’m back to firefox.

While connected to any server through the browser (firefox only) extension, site like ipleak.net and https://www.dnsleaktest.com show that the DNS is leaking. This behaviour does not happen if I connect through the windows app alongside firefox.

I tried changing the DoH settings, but that does not fix it.

2

if you have uBlocker origin you need to uncheck the option “uncloak canonical names” on the extension. On Firefox it comes enabled by default, in chromium based browser it is greyed out or missing and that’s why you don’t have leaks there

3

https://protonvpn.com/support/browser-extensions/

#3

4

Change your ISP DNS to Google DNS or something like that and you’ll never get a DNS leak even if you don’t use the VPN.

5

Changing network.trr.mode to 3 fixed my problem.

6

just use the standalone app…problem solved.

7

thanks bro

i use windscribe addon , was thinking to switch protonvpn

and by the way , almost all firefox user uses ublock

8

So I thought that fixed it, but turns out that on https://browserleaks.com/ip it still leaks Google DNS somehow. Works fine when connected through windows app once again. Weird.

9

I’ll try this and report back, thanks

10

This just makes whatever would leak to Google, to go to Cloudfare or whatever I pick in the settings

11

I understand what you’re saying, and it is leaking the google DNS whatever other DNS I set it to, but the point is that the extension is flawed, not that there is no workaround to it

12

On https://browserleaks.com/ip dns test too? It’s the only place that shows my chosen DoH provider (cloudfare) alongside proton vpn dns

13

Is it solved, though?

14

Wait, after further testing here, both dns leak testers on the OG post were okay after disabling the canonical names, but testing on https://browserleaks.com/ip still shows a leak that goes through google if I use extension vs windows app. Weird.

15

waiting for your report

16

True. What is your browser extension use case?

17

i don’t use the browser extention. i use the app it’s far better. i ran leak tests on THREE different DNS test sites and all came back the same…NO DNS LEAKS… it is solved.

18

in Firefox settings under privacy and security check “DNS on HTTPS” to be disabled

19

thanks bro,thats why i dont believe on addons, for extra safety i use vpn client also

20

OP, please check the support article for what u/FlowerBudget2065 suggested. Another alternative is using the VPN extension in a private window.