Change network configuration on Ubuntu Server

This article is relevant for Ubuntu versions Ubuntu 20.04 or later using /etc/netplan configuration.

The configuration applicable can be done with editor nano in file is in file /etc/netplan/50-cloud-init.yaml:

sudo nano /etc/netplan/50-cloud-init.yaml

The configuration for WiFi is in section wifis: and the configuration for cable LAN is in section ethernets:

The indentation needs to be correct for the .yaml to work. Example to set the ethernet connection to a static IP 192.168.1.10 connected to router 192.168.1.1:

network:
    ethernets:
        eth0:
          addresses:
            - 192.168.1.10/24
          gateway4: 192.168.1.1
          nameservers:
            addresses: [192.168.1.1]
          optional: true

Example configuration for WiFi obtaining the IP address from DHCP:

network:
    wifis:
      wlan0:
        dhcp4: true
        optional: true
        access-points:
          "home network":
            password: "123456789"

To apply the netplan changes, enter:

sudo netplan apply

Alternatively, if you run into some issues use:

sudo netplan --debug apply