Adding public IPv4 and IPv6 addresses to a VPS or migrated Cloud Server (Ubuntu 20.04, 22.04, 24.04, and Debian 12 with Netplan)

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

• 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 OLD_CONFIGURATION_FILE.yaml OLD_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:
      NETWORK_INTERFACE:
        addresses:
          - MAIN IPv4 ADDRESS/32
          - ADDITIONAL IPv4 ADDRESS/32
          - MAIN IPv6 ADDRESS/64
          - ADDITIONAL 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
          - 2a02:247a:21f:9c00::2/64
        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 NETWORK_INTERFACE 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 and the additional IPv6 address. To do this, replace the placeholders.

• 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/01-netcfg.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