With my Samsung galaxy s6 authentication error occurred how can I sort this out

SOURCE: unable to obtain authentication input/output.

if u r using your scanner on jamb website. You will need a biometric license and offline software. We have several license in stock to give away. While not call us today, if the problem is still persisting. Call 08132829820

SOURCE: I am having Samsung GT-S5620

I am using samsung GT-S5620 Mobile and internet prepaid connection of bsnl but on mobile i trying to open internet i.e googlesearch and other search engine there is message display DNS failed

SOURCE: I can't get passed this on my Samsung Galaxy s6 it won't do anything else how do I reset it

Go to
*settings
*general
* back up and reset

SOURCE: a phone it's a Samsung Galaxy s6 edge. Question it keeps saying checking connection and then "couldn't connect to the Internet "

Make sure you data is on to get to that go to
*settings
*connection
*mobile data