I had installed connman (Connection Manager package) on my Fedora 23, and did not pay attention to the installation dialogues, which would have replaced NetworkManager as default connection management tool. That was the biggest mistake I could have made. Connman did not trouble me then, but as soon as I upgraded my distribution to latest, Fedora 25, the internet stopped working. The ethernet link was active though. I had a similar problem a while ago on my home laptop, but since I was in a hurry and had a separate /home partition, I just did a fresh install (debugging connman without internet took 25 minutes without solution, and re-installation took 15 minutes, poor me!). But on my office work station, there was no option for re-installation, so I had to debug the issue. From my past experience I knew the problem was related to connman, since I could see the /etc/resolv.conf was not taking DNS values which I set in NetworkManager GUI. By checking at the file, I found it as a dangling symbolic link to /var/run/connman/… I uninstalled connman in a hope that the link would be re-created to a proper file but that did not happen. So I searched for resolv.conf file in /usr/ and found one under systemd directory, which already had DNS information stored to 127.0.0.53, which is not correct. Still I pointed /etc/resolv.conf to that location, and there was no success either. In the desperation I just removed the link, and restarted the NetworkManager systemd service, and to my surprise, this fixed the problem.
For someone, who has a similar problem, here is the correct link for the /etc/resolv.conf
➜ ~ ls -l /etc/resolv.conf lrwxrwxrwx. 1 root root 35 Jun 7 07:09 /etc/resolv.conf -> /var/run/NetworkManager/resolv.conf