What DNS servers are used when connected to wireless data (not wifi)?
Is there a way within Android KitKat to tell?
Run "nslookup google.com" from Terminal Emulator and the first result should be your DNS. Also you could run a standard test from dnsleaktest.com from your browser.
setprop method to change DNS does not work, the
getprop method to read those values should be still valid today:
shell@A0001:/ $ getprop | grep dns [dhcp.wlan0.dns1]: [192.168.1.1] [dhcp.wlan0.dns2]:  [dhcp.wlan0.dns3]:  [dhcp.wlan0.dns4]:  [net.change]: [net.rmnet0.dns2] [net.dns1]: [188.8.131.52] [net.dns2]: [184.108.40.206] [net.rmnet0.dns1]: [220.127.116.11] [net.rmnet0.dns2]: [18.104.22.168] [net.wlan0.dns1]: [22.214.171.124] [net.wlan0.dns2]: [126.96.36.199]
To clarify my answer: using a terminal emulator app (like Terminal Emulator for Android), as a normal user (no root permissions needed), you can execute the command I showed (
getprop | grep dns) and get an output like that.