Mullvad browser and DNS servers

When I use Mullvad browser on linux it uses different DNS servers to any other browser I use.

For example if I connect to a mullvad’s VPN NZ server then I do a check at https://mullvad.net/en/check then Brave will tell me it is using an NZ DNS server (which would be logical). Whereas Mullvad will tell me it is using a UK DNS server.

Does anyone know why this is the case? It gives me pause in using the browser at the moment.

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Are you are connected to Mullvad UK from the extension?

I’m not using any extension. I’m only using the linux Mullvad app and vanilla Mullvad and vanilla Brave (same results with Firefox of course).

I have zero connection with the UK.

If I change the VPN to a SYDNEY server then https://mullvad.net/en/check actually says there are DNS leaks! It shows a different UK server. Crazy when I’m using mullvad VPN and browser!

This should be easy for anyone to recreate. You don’t even need to be using a VPN. Mullvad browser will give you different DNS servers regardless. If I use no VPN then Mullvad Browser uses a DNS server in Singapore whereas Brave (or any other browser) uses a DNS server in my local location as you’d expect.

If this is all part of the design then no problems, I’d just like an explanation as to why.

What is your local DNS set to?

How about your router’s DNS setting?

The upstream provider?

It’s not just me. I posted this on the reddit forum and there is are a couple of replies saying they have the same issue. Whereas no one has said they can’t recreate the problem.

No other browser has this issue on my machine. The issue is with the Mullvad browser (at least on linux) and not with my local DNS settings (which are irrelevant when I’m using a VPN anyway because the browser will use the VPN DNS UNLESS it is deliberately choosing to use an alternative).

If anyone here can’t recreate the problem on linux (maybe Windows too I don’t now) I’d be very surprised. If you don’t have a VPN then that doesn’t stop you recreating it. Mullvad Browser will always use a different DNS to any other browser - if that behaviour is expected then fine if not then there is a problem.

This is because the browser is already set to the DoH server. If you set the same DoH server (Mullvad DNS-over-HTTPS address) to other browsers you will use the same DNS server as MB. I started a thread here about whether it is necessary to change the pre-set DoH server, but there is still no explanation in the browser recommendation section.

It may be due to so that everyone with MullvadBrowser will use the same DNS and look the same.

The bad part is that the controller of the DNS server has some control ovee your web content.

It might not be malicious, just bad design decision that looked good on paper?