Ensure a network interface is up and start on boot

During a precent project, I was setting up a VM with multiple network interfaces, but the interface I added wasn't up.

Ensure the interface is up #

# Up interface
sudo ifconfig <interface_name> up

# Request IPv4 address
sudo dhclient <interface_name>
ip a

Ensure the interface is up at boot #

For that, we need to update netplan configuration.

Add interface to config file #

Create or open /etc/netplan/01-netcfg.yaml If you create it, permissions should be sudo chmod 0600 /etc/netplan/01-netcfg.yaml

sudo nano /etc/netplan/01-netcfg.yaml

network:
  version: 2
  ethernets:
    enp0s3:
      dhcp4: yes
    # add interface you want below  
    INTERFACE_NAME:
	  dhcp4: yes

Apply the changes #

sudo netplan apply

Remove an IP address for an interface #

sudo ip addr del <IP ADDRESS> dev <INTERFACE>