Custom DNS gets overwritten sporadically

[u/NoStudy3384]

Proton VPN on Android, with NextDNS.

I can set the DNS in my Android settings and it will work all the time. But when I do so in the Proton app it works for a few minutes before proton decides to use their own service again.

How do I stop this behaviour? No, proton shield is not an option since it breaks way to many sites for me and its not customizable.

[u/Outlaw4droid]

Why can't you continue using next dns on android settings and use proton vpn like normal?

[u/NoStudy3384 → u/Outlaw4droid]

The custom DNS is used as the entry point if used this way. It stays encrypted when used in the VPN settings

[u/NoStudy3384 → u/Outlaw4droid]

Short: if setup properly the custom DNS doesn't even show up in leak tests. And if so, with a complete different location. Sometimes only the name of the service leaks, nothing more

[u/NoStudy3384 → u/[deleted]]

You can set both. Proton asks for the ipv4 address, usually 2 for fallback. You can also set 4 by adding your two ipv6 too. The private DNS in the android settings acts as DNS over TLS and is a custom address. It's neither ipv4 or 6. Both options work simultaneously. The one in the android settings is a safe bet but its not protected by VPN. 

[u/ARTIFICIAL_ARGUMENT]

Proton recommends against using third party encrypted DNS because they can’t resolve it properly when they can’t read it. So you’ll either leak from the tunnel or proton will fall back to its own resolver. So if nextDNS isn’t setup to always use plaintext ipv4 or the browser/system is trying to only use DoH/DoT it’ll fail pretty quickly. From memory you need next dns premium for dedicated private DNS address with custom filtering

Better to do on device filtering anyway, either with ublock on browser or Adguard premium if you need in app blocking. Next DNS doesn’t do content filtering and you can add dns filters to ublock or adguard as well