i have nearly the same problem in

[Set Open DNS in Android 5.0.1][1]


  [1]: https://android.stackexchange.com/questions/109844/set-open-dns-in-android-5-0-1?newreg=08ac8fdfbb7341fea7e27f4f64642016

and the answer helped me.
although I want to change the DNS for block porn
what values for the other fields should i enter?
i have HTC mobile with 5.1 Android version