Adding Multiple Public IPv4 and IPv6 Addresses on a VPS (Ubuntu 20.04, 22.04 and Debian 12)

For VPSs purchased after May 16, 2023

If you assign an IPv4 address and one or two IPv6 addresses to a VPS, these IP addresses are automatically configured in the operating system.

This article explains how to manually configure public IPv4 and IPv6 addresses in the operating system of a VPS on which Ubuntu 20.04, Ubuntu 22.04 or Debian 12 is installed. This is necessary if you assign two IPv4 addresses and at least one IPv6 address to a VPS.

The network configuration is completed in the images of IONOS for Ubuntu 20.04, Ubuntu 22.04 and Debian 12 via netplan. The network configuration is controlled via files with the file extension .yaml, which are located in the directory /etc/netplan. If there are several files in this directory, they are loaded in lexical order.

How to configure an additional, public IPv4 address in Ubuntu 20.04, Ubuntu 22.04 and Debian 12:

To check whether your server is already using netplan for the network configuration, proceed as follows:

• 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_CONFIGURATIONFILE.yaml OLD_CONFIGURATIONFILE.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
          - ADDITIONAL IPv6 ADDRESS_1/64 
   
        nameservers:
          addresses:
            - IP ADDRESS OF NAME SERVER 1
            - IP ADDRESS OF NAME SERVER 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:
          - 82.165.34.29/32
          - 195.20.236.17/32
          - 2a02:247a:21f:9c00::1/64
          - 2a02:247a:021f:9c00:0000:0000:0000:0000/64 
        nameservers:
          addresses:
            - 212.227.123.16
            - 212.227.123.17  
        routes:
          - on-link: true
            to: default
            via: 82.165.34.1
    version: 2

• Replace the NETWORKINTERFACE placeholder with the network interface that you have determined. Then enter the main IPv4 address, the additional IPv4 address and the IPv6 addresses. To do this, replace the appropriate 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 01-netcfg.yaml file so that the file can only be read and changed by the root account, enter the following command:

  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