Hello every! I'm just creating this post, not to have the full help, but to help other who can have the same problem. The issues shows when you follow this tutorial to install centOS 7 in the OVH VPS. NEVER install the package NetworkManager-tui and I didn't tried only installing the net-tools or you will have a big trouble with the virtual network connection, it'll broken and the service network wouldn't start. The only solution I found was reinstall the server, it's true that I'm an amateur linux user, even I tried many things to have the connection up. Maybe later I try again how to solve the trouble without reinstalling the server.