Static IP

Static IP Configuration with Netplan on Ubuntu

Follow these steps to disable cloud-init network management, define a static IP for your VM, and apply the configuration.

1. Disable cloud-init network configuration

By default, cloud-init will overwrite /etc/netplan/01-netcfg.yaml on each boot.
To prevent this, make sure the following file exists:

sudo tee /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg <<EOF
network: {config: disabled}
EOF

2. Edit your existing Netplan configuration

Instead of creating a new file, edit the existing one /etc/netplan/01-netcfg.yaml. Adjust the interface name (enp0s8 in most VirtualBox setups), IP address, prefix, gateway and DNS as needed:

network:
  version: 2
  renderer: networkd
  ethernets:
    enp0s8:
      dhcp4: no
      addresses:
        - 192.168.1.127/24
      routes:
        - to: default
          via: 192.168.1.1
      nameservers:
        addresses: [8.8.8.8, 1.1.1.1]

Note: Always confirm your interface name with ip a. It may appear as enp0s3, enp0s8 or something else depending on your VM configuration. Use exactly the name shown in the output.

3. Secure the Netplan file

Netplan requires its files to be unreadable by group/other. Set permissions to 600:

sudo chmod 600 /etc/netplan/01-netcfg.yaml

4. Generate and apply the new config

Generate the backend files, then apply changes:

sudo netplan generate
sudo netplan apply

5. Validate and reboot

Check that only your static IP is present:
```
ip a show dev enp0s8
```
Reboot to confirm persistence:
```
sudo reboot
```
After reboot, run ip a again — you should see only 192.168.1.127/24 on enp0s8.

Tip: If you ever need to revert, rename or delete /etc/netplan/01-netcfg.yaml and also delete /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg, then reboot.