I just upgraded to 17.04. My internet connection appears broken, I can’t use Thunderbird or Firefox. The message for TBird says it can’t find the server. I am using a wired ethernet connection. Things are working with Zorin so this must be an upgrade related problem. It was working fine on 16.04.
I had the same problem a week ago
It is so simple to make it to work again. Just boot to the previous kernel and reinstall the latest.
To do it first shutdown your computer. Keep pressing the shift button while you open your computer and the grub menu will appear.
Select advanced options and select the second kernel NOT THE RECOVER MODE press enter. Open the terminal and type
sudo add-apt-repository ppa:teejee2008/ppa
sudo apt-get update && sudo apt-get install ukuu
open ukuu from the menu and find the latest kernel and remove it type in the terminal
grub-update reboot open update manager and upgrade everything
yes, I asked if you could enter that command in a terminal to see if you can reach internet. The same could be tried using Firefox and go to a website. @steven and @konmal88 suggested to boot with a previous kernel and try that. Maybe there was an issue with 17.04
OK, I tried “pinging” in terminal to get online. that didn’t work.
I then tried the restart network commands from knomal88, those didn’t work either.
I am thinking of trying to restore 16.04 from a Clonezilla image I made a few months ago. Although I have not successfully restored a Clonezilla image thus far.