networkmanager does not recognize the names of the internet servers

Hello

My 17.10 ubuntu session loops on the password request probably following the installation of version 4.13.0-19

I decide to use the RECOVERY mode
         fsck command
         network activation
         dpkg command
         choice to become the ROOT user
             command ping 8.8.8.8 gives excellent response times
             command ping www,google.com returns UNKNOWN HOST

I decided to run an ubuntu instance 16.04 LTS which works perfectly well to check if ping www.google.com is known. It is well recognized.

But when I decide to restart ubuntu 16.04 in recovery mode, i have the same problem (unkwon host).

Here are some traces made in version 16.04

a) ubuntu version
b) good ping
c) manual copy of the network restarting command
d) systemctl status Networkmanager.service
e) journalctl -xe

What to do to make the network work normally in RECOVERY mode?

networkmanager does not recognize the names of the internet servers