Private DNS doesn't work in mobile network


I am unable to use cloudflare dns as “private dns” in mobile networks. I’ve configured as address. If I disable wifi it will show “Couldn’t connect” in Settings->Wifi&Internet->Private DNS after some seconds.

Device/OS: Oneplus 6 with Android P OxygenOS (beta 2)
Country: Austria
Mobile isp: “yesss!” which is a discounter in the “A1 Austria” mobile network.

Unfortunately I cannot test it with another mobile isp because I don’t know anyone else with android p & a different isp. However I am able to ping form my phone with a normal ping (avg 70-100, max. ~350)


Ich bin mir nicht sicher, ob die Nutzung von eigenen DNS Servern (ohne VPN) überhaupt möglich ist. Ich habe mehrere Jahre bei einem Provider in D gearbeitet, da war nichts mit eigenen DNS Servern. Ist allerdings auch schon ein paar Jährchen her.

Die Telekom schmeißt mich sogar aus ihren Hotspots, wenn ich nicht den per DHCP zugewiesenen DNS nutze, sondern den in meinem VPN.

Kannst du einen Traceroute zu von deinem Handy ausführen? Via 4G


Lets keep it on english so other people understand what we’re talking about.

As I said in the OP I am using the new “private dns” feature of android P. It allows you to configure a private dns server which will as far as I know override mobile network and wifi dns.

I tried to do a traceroute but it always shows me “Request timed out”.


Need to correct myself, the traceroute only timed out for some hops. So I got 6 timesouts. After them I see (2000ms) (48ms) (30ms)


  • The port is not blocked. I opened a server with the dns over tls port (853) and I was able to connect using telnet.
  • The quad9 dns works (