Actually yesterday I've upgraded from Ubuntu 16.04 to 17.04 and I got a problem that, if connect LAN cable it does not showing anything and remains disconnected. But i can connect with WiFi. I don't know what's the problem. Actually its showing "device not managed" under the "Ethernet Network" and both were disabled. I've searched for the solution, but did not found yet.
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1I'm having the same problem, I did what was suggested but still don't see the ethernet connection nor does it connect, it connects to the wifi fine. the light is on with the cable connected. I restarted the laptop and it still isn't there. Worked find in 16.04– casawyerApr 25, 2017 at 5:55
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1This seems duplicate of another question. See answer askubuntu.com/a/909648/170833 should solve this same problem too (I had same problem with ethernet cable on a computer that had it, and also with a USB type C dongle with ethernet on a second computer without 'native' ethernet)– morhookApr 30, 2017 at 23:47
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1This is Ubuntu bug #1676547, please consider providing information that will help fixing the bug there (but not "me, too" style commentary). Thanks.– TomOct 8, 2017 at 8:00
3 Answers
Here is the fix for the LAN problem that first occurred mildly in 16.04, got a bit worse in 16.10 and became unbearable in 17.04 rendering it unusable:
sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo service network-manager restart
This creates a blank file needed in the /etc/NetworkManager/conf.d
directory which the installer fails at creating automatically. The real question that should be asked is why are such critical things left unresolved for so long to cause needless worry and lost time for many people?
UPDATE: In addition to the above, the culprit seems to be the file with the same name in /usr/lib/NetworkManager/conf.d/
. Either comment out (by inserting a hash at the beginning of each line) or delete all its contents to make it a blank file using a text editor such as gedit:
sudo tee /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf < /dev/null
Alternatively, backup the existing file, and add e.g. _backup to its name to be safe, and create a new blank file. I actually went back to 16.04LTS for a while due to this problem, but now the networking is functional under 17.04.
Most probably your interface appears in /etc/network/interfaces. By default, NetworkManager does not manage interfaces that appear in /etc/network/interfaces. You can change this behaviour.
To do this - in a terminal:
sudo nano /etc/NetworkManager/NetworkManager.conf
change the line managed=false
to managed=true
Save, stop and start network manager:
sudo service network-manager restart
EDIT 1
Try this. Remove the interface from /etc/network/interfaces
.
backup the current interfaces file:
sudo cp /etc/network/interfaces /etc/network_interfaces_backup
Then open the file:
sudo nano /etc/network/interfaces
Delete everything in that file and copy and paste the following:
auto lo
iface lo inet loopback
Save, stop and start network manager:
sudo service network-manager restart
After this check that you have Enabled Networking ticked
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By default, its true on my PC, see here: s7.postimg.org/uxs8ozwx7/… The thing is, its showing "device not managed". And I've searched a lot on google, still no use!– RuD3B0yApr 18, 2017 at 9:18
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2I'm having the same problem with my HP-15 after upgrading to 17.04, I did what was suggested and still no ethernet connection showing or active.– casawyerApr 25, 2017 at 6:56
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1
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1Changing managed from =false to =true seemed to have worked for me, It seems to be intermittent so I will see. I run a VPN with OpenVPN so this may be an issue with 17.04. May 4, 2017 at 10:42
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1This answer worked for me. I understand that the other (most voted) may work for other scenarios but in my specific case this solved it. Thanks.– eburgosSep 28, 2017 at 2:34
This solved my problem. Edit this file:
sudo -H gedit /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf
You need to explicitly add ethernet devices to be managed. To do so the contents of the file should be like this:
[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:wwan,except:type:ethernet
After that, just restart the NetworkManager service:
sudo service network-manager restart