Adding a public IPv4 addresses to a VPS or a migrated Cloud Server (Ubuntu 24.04, 22.04, 20.04, and Debian 12 with Netplan)

To check whether your server is already using netplan for the network configuration, enter the following command:

• Change to the /etc/netplan directory.

  [root@localhost ~]# cd /etc/netplan

• Check whether there is already a configuration file in this directory. To do this, enter the following command:

  [root@localhost ~]# ls

To display the DNS servers used, enter the following command:

[root@localhost ~]# resolvectl --no-pager |grep Server

The DNS servers used are then displayed at the end of the output.

Example:

[root@localhost ~]# resolvectl --no-pager |grep Server
Current DNS Server: 212.227.123.16
DNS Servers: 212.227.123.16 212.227.123.17

Make a note of the DNS servers.

• Check whether there is already a configuration file in this directory. To do this, enter the following commands:

  [root@localhost ~]# cd /etc/netplan
  [root@localhost ~]# ls /etc/netplan

• If there is a configuration file in this directory, rename it. To do this, enter the following command and replace the placeholders.

  root@localhost ~]# mv CONFIGURATION_FILE.yaml CONFIGURATION_FILE.yaml.old

  Example:

  [root@localhost ~]# mv 50-cloud-init.yaml 50-cloud-init.yaml.old

• Create the file /etc/netplan/01-netcfg.yaml with the vi editor. To do this, enter the following command:

  [root@localhost ~]# vi etc/netplan/01-netcfg.yaml

• Insert the following information:

  network:
  version: 2
  renderer: networkd
  ethernets:
  NETWORKINTERFACE:
  addresses:
  - MAIN IPv4 ADDRESS/32
  - ADDITIONAL IPv4 ADDRESS/32
  - MAIN IPv6 ADDRESS/64
  nameservers:
  addresses:
  - IP ADDRESS OF NAMESERVER 1
  - IP ADDRESS OF NAMESERVER 2
  routes:
  - on-link: true
  to: default
  via: STANDARD GATEWAY OF THE ACTIVE INTERFACE
  version: 2

  Example:

  network:
  version: 2
  renderer: networkd
  ethernets:
  ens6:
  addresses:
  - 195.20.234.94/32
  - 195.20.234.86/32
  - 2a02:247a:21f:9c00::1/64
  nameservers:
  addresses:
  - 212.227.123.16
  - 212.227.123.17
  routes:
  - on-link: true
  to: default
  via: 195.20.234.1
  version: 2

• Replace the NETWORKINTERFACE placeholder with the determined network interface. In this example, this is the network interface ens6.

• Then enter the main IPv4 address and the additional IPv4 address. To do this, replace the placeholders.

• Enter the main IPv6 address.

• Replace the placeholders IP ADDRESS OF NAME SERVER 1 and IP ADDRESS OF NAME SERVER 2 with the determined name servers.

• Replace the placeholder STANDARD GATEWAY OF ACTIVE INTERFACE with the determined IPv4 gateway.

• To exit vi and save the file, enter the command :wq and then press Enter.

• To change the permissions of the new configuration file so that the file can only be read and changed by the root account, adapt the following command and then enter it:

  root@localhost:~# sudo chmod 600 /etc/netplan/CONFIGURATION_FILE.yaml

  Example:

  root@localhost:~# sudo chmod 600 /etc/netplan/50-cloud-init.yaml

• To check the configuration file, enter the following command:

  root@localhost:~# netplan --debug apply

• Restart the server so that the changes are applied. To do this, enter the following command:

  root@localhost:~# systemctl reboot

• To check whether the additional IPv4 address has been configured correctly, enter the following command:

  root@localhost:~# ip addr