Disable systemd-networkd on Ubuntu Linux

We recently got an error indicating that systemd-networkd is not supported in the deployment of CRC – CodeReady Containers on Ubuntu Linux. systemd-networkd is a network management tool that replaces the network scripts traditional method of setting up networking on Ubuntu.

In this post we show you how to switch to NetworkManager network configuration tool from systemd-networkd. First confirm if systemd-networkd is running:

$ systemctl status systemd-networkd.service
● systemd-networkd.service - Network Configuration
     Loaded: loaded (/usr/lib/systemd/system/systemd-networkd.service; enabled; preset: enabled)
     Active: active (running) since Tue 2024-07-16 20:26:56 UTC; 6min ago
TriggeredBy: ● systemd-networkd.socket
       Docs: man:systemd-networkd.service(8)
             man:org.freedesktop.network1(5)
   Main PID: 712 (systemd-network)
     Status: "Processing requests..."
      Tasks: 1 (limit: 38473)
   FD Store: 0 (limit: 512)
     Memory: 3.1M (peak: 3.3M)
        CPU: 29ms
     CGroup: /system.slice/systemd-networkd.service
             └─712 /usr/lib/systemd/systemd-networkd

Jul 16 20:26:56 noble systemd[1]: Starting systemd-networkd.service - Network Configuration...
Jul 16 20:26:56 noble systemd-networkd[712]: lo: Link UP
Jul 16 20:26:56 noble systemd-networkd[712]: lo: Gained carrier
Jul 16 20:26:56 noble systemd-networkd[712]: Enumeration completed
Jul 16 20:26:56 noble systemd[1]: Started systemd-networkd.service - Network Configuration.
Jul 16 20:26:56 noble systemd-networkd[712]: ens3: Configuring with /run/systemd/network/10-netplan-ens3.network.
Jul 16 20:26:56 noble systemd-networkd[712]: ens3: Link UP
Jul 16 20:26:56 noble systemd-networkd[712]: ens3: Gained carrier
Jul 16 20:26:56 noble systemd-networkd[712]: ens3: DHCPv4 address 188.40.183.239/27, gateway 188.40.183.225 acquired from 188.40.183.226
Jul 16 20:26:58 noble systemd-networkd[712]: ens3: Gained IPv6LL

Step 1: Set NetworkManager as netplan renderer

List netplan configuration files.

$ ls  /etc/netplan/
50-cloud-init.yaml

You can list contents of the default file.

$ cat /etc/netplan/50-cloud-init.yaml
# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    version: 2
    ethernets:
        ens3:
            dhcp4: true
            match:
                macaddress: fa:16:3e:69:e3:05
            set-name: ens3

Open the .yaml config file and set renderer to NetworkManager after version:

$ sudo nano /etc/netplan/50-cloud-init.yaml
network:
  version: 2
  renderer: NetworkManager

Step 2: Install Install NetworkManager

Run the following commands to install NetworkManager.

sudo apt update && sudo apt install network-manager

Disable and mask systemd-networkd services.

sudo systemctl disable systemd-networkd.service systemd-networkd.service
sudo systemctl mask systemd-networkd.service systemd-networkd.socket

Start and enable NetworkManager service.

sudo systemctl enable NetworkManager
sudo systemctl start NetworkManager

Step 3: Generate netplan config and reboot system

Generate netplan backend configuration files for NetworkManager:

sudo netplan generate

Reboot your Ubuntu system.

sudo reboot

After the reboot check NetworkManager service.

$ systemctl status NetworkManager
● NetworkManager.service - Network Manager
     Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; preset: enabled)
     Active: active (running) since Tue 2024-07-16 20:55:11 UTC; 1min 45s ago
       Docs: man:NetworkManager(8)
   Main PID: 766 (NetworkManager)
      Tasks: 4 (limit: 38473)
     Memory: 14.5M (peak: 31.0M)
        CPU: 316ms
     CGroup: /system.slice/NetworkManager.service
             └─766 /usr/sbin/NetworkManager --no-daemon

Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.0317] dhcp4 (ens3): state changed new lease, address=188.40.183.239, acd pending
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1587] dhcp4 (ens3): state changed new lease, address=188.40.183.239
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1590] policy: set 'netplan-ens3' (ens3) as default for IPv4 routing and DNS
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1621] device (ens3): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1632] device (ens3): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1633] device (ens3): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1636] manager: NetworkManager state is now CONNECTED_SITE
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1638] device (ens3): Activation: successful, device activated.
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1641] manager: NetworkManager state is now CONNECTED_GLOBAL
Jul 16 20:55:11 noble NetworkManager[766]: <info>  [1721163311.1643] manager: startup complete

You can also use nmcli to see active interfaces managed by NetworkManager.

$ nmcli connection show
NAME          UUID                                  TYPE      DEVICE
netplan-ens3  bec3d02a-c9e5-3283-92ab-ee43a4246c85  ethernet  ens3
lo            b82852c2-8ea4-4660-8536-42a4273c0965  loopback  lo

In this article we’ve shown you how to switch from systemd-networkd to NetworkManager on an Ubuntu system. If you are stuck our Engineers are available to help out with any issues.