ping 8.8.8.8 works but ping www.google.com doesn't

You need a Name Server in your /etc/resolv.conf file. Edit your /etc/resolv.conf and add a working Name Server. Google provides a free one, 8.8.8.8.

Do this:

$ nano /etc/resolv.conf

Place this as the first non-commented line:

nameserver 8.8.8.8

You can verify this functionality with:

$ ping -c10 www.google.com

You can make this change permanent by adding the line to this file your /etc/resolvconf/resolv.conf.d/head file.

Could you post a link to the page that told you that file resolv.conf should be empty? My guess is that it is misleading at best.

Edit that file with command sudo nano /etc/resolv.conf and put there a single line:

nameserver 8.8.8.8

That should fix your name resolution and the various programs that use it - ping, apt-get, etc.

You also ought to investigate why resolv.conf is empty. Perhaps your DHCP server isn't configured properly.

The marked answer actually doesn't work on Ubuntu 18.04.01. To fix this issue, here's what I did:

• Execute sudo gedit /usr/lib/systemd/resolv.conf
• Paste nameserver 8.8.8.8 (and/or any other nameserver(s) you want), then save and exit.
• Add a symlink by executing sudo ln -sf /usr/lib/systemd/resolv.conf /etc/resolv.conf

Credits to https://askubuntu.com/a/1050280/899241