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user2315094
Asked: 2020-04-05 00:55:56 +0800 CST

Ubuntu 18.04.4 Desktop: since last upgrade : Wired unmanaged with the previous network configuration files

  • 772

Last evening I made the requested packages upgrade for Ubuntu 18.04.4 Desktop. But now I'm not able to connect to the network anymore with the previous network configuration files. These are the packages upgraded:

enter image description here

Here's the NetworkManager.conf file content: 

$ sudo nano /etc/NetworkManager/NetworkManager.conf

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

[device]
wifi.scan-rand-mac-address=no

Following these indications: No wired connection - Wired unmanaged ubuntu 18.04

I tried to put managed=true in /etc/NetworkManager/NetworkManager.conf and run 

sudo service network-manager restart

followed by a system reboot.
But the problem still persists.

Modifying the 01-network-manager-all.yaml file: 

$ sudo nano /etc/netplan/01-network-manager-all.yaml
#Let NetworkManager manage all devices on this system
network:
  version: 2
  #renderer: networkd
  ethernets:
    enp3s0:
      dhcp4: no
      addresses: [192.168.1.7/24]
      gateway4: 192.168.1.1
      nameservers:
        addresses: [8.8.8.8, 8.8.4.4]

to

network:
  version: 2
  renderer: NetworkManager
  #renderer: networkd
  ethernets:
    enp3s0:
      dhcp4: trye
      #dhcp4: no
      #addresses: [192.168.1.7/24]
      #gateway4: 192.168.1.1
      #nameservers:
      #  addresses: [8.8.8.8,8.8.4.4]

made the wired connection working again.

What happened due to this Ubuntu 18.04 package upgrade?

networking upgrade wired 18.04 netplan

3 Answers

  1. Best Answer

    NetworkManager

    Edit /etc/NetworkManager/NetworkManager.conf and change "managed" back to false.

    Assure that /etc/network/interfaces only contains the following active lines:

    # interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

    Set your /etc/netplan/01-network-manager-all.yaml back to:

    network:
  version: 2
  renderer: NetworkManager

    sudo netplan generate

    sudo netplan apply

    reboot

    Then configure your wired connection using the NetworkManager GUI.

    • 4

  2. The /etc/netplan/01-network-manager-all.yaml file that you posted is not the default netplan configuration that is provided by the Ubuntu desktop installer. The most likely explanation for this behavior is that you edited (with an editor or through some software) this file, and after applying the latest updates you rebooted, causing Network Manager to respect the new config which told it not to manage the wired ethernet interface.

    • 0

  3. I have try and it works.

    sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo systemctl restart NetworkManager
    • 0