On the Internet, all connected devices are assigned their own IP addresses. When you open a website in Android (or any other operating system), it first checks with the DNS servers to translate the domain name into its IP address before it is opened in your browser. Usually your ISP assigns you their own DNS servers, but they could be slow in response and do not provide any security features like the ones provides by OpenDNS or Norton DNS servers. For these reasons, if you want to change the DNS servers in Android then you can use the free DNS Changer app. This app allows you to change the primary and secondary DNS servers to one of the popular ones or but you can also manually enter the DNS server addresses.
The DNS Changer app for Android required a rooted device. You must have superuser (also called su access or root access) in your Android device for this to work.
After you have installed DNS Changer, you can launch it from the All Apps screen. On the screen that shows up, you have to select the primary DNS server as well as secondary DNS server. You can tap on Select from list of DNS button to open a list of the preset DNS servers which includes all the popular servers like Google Public DNS, Open DNS, Open DNS Family, Norton DNS server and so on. But you can also manually type in the IP addresses. After this you have to tap on the Set button to save the settings.
If you are not satisfied by manually changing the DNS servers for the current network you are using to connect to the Internet, then you can automate the whole process. This way you can change the DNS servers as soon as the networks like WiFi or 3G become available.
The automation settings can be accessed through the menu of this app. In the settings, you have to choose a default primary and secondary DNS server to be set for all the future networks. You can also choose where you want to automate for 3G networks or for WiFi networks, and whether to show the notifications when it is done.
Conclusion: By setting a secure DNS server like Norton ConnectSafe DNS or Open DNS, you can block malicious or inappropriate sites in Android. The DNS Changer app in Android allows you to set these DNS server very easily. Through this app, you can also automate the DNS server settings as new networks are discovered.
You can download DNS Changer app from https://play.google.com/store/apps/details?id=com.eddypcz.dnschanger.