Adding Public IPv4 Addresses on a VPS (Debian 10)

For VPSs purchased after May 16, 2023

This article explains how to add additional, public IPv4 addresses on a VPS that has Debian 10 installed.

How to configure additional, public IPv4 addresses in Debian 10:

To determine the filename of the network interface, enter the following command:

root@debian:~# ip addr

In this example, the name of the network interface is ens6:

root@debian:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 02:01:16:8b:79:11 brd ff:ff:ff:ff:ff:ff
    inet 82.165.34.29/32 brd 82.165.34.29 scope global dynamic ens6
       valid_lft 517sec preferred_lft 517sec
    inet6 fe80::1:16ff:fe8b:7911/64 scope link
       valid_lft forever preferred_lft forever

Make a note of the name of the network interface and the network mask. This is listed on the line that contains the main IP address. The network mask is specified in the CIDR notation. The notation 195.20.234.94/32 corresponds to the address 195.20.234.94 with the network mask 255.255.255.255.

For more information about CIDR notation, see the following article:

CIDR: What is Classless Inter-Domain Routing?

• Create the configuration file /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg. To do this, enter the following command:

  root@debian:~# vi /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

• Add the following entry:

  network: {config: disabled}

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

• Open the /etc/network/interfaces file with the vi editor. Type the following command:

  [root@localhost ~]# vi /etc/network/interfaces

• Replace the existing entries with the following information:

  auto lo INTERFACE_DEVICE
  iface lo inet loopback
  
  allow-hotplug INTERFACE_DEVICE
  iface INTERFACE_DEVICE inet static
   address MAIN IPv4 ADDRESS/32
  netmask NETWORK MASK
  gateway STANDARD GATEWAY OF ACTIVE INTERFACE
  
  auto INTERFACE_DEVICE:0
  allow-hotplug INTERFACE_DEVICE:0
  iface INTERFACE_DEVICE:0 inet static
   address ADDITIONAL-IPv4-ADRESS/32

  Example:

  auto lo ens6
  iface lo inet loopback
  
  allow-hotplug ens6
  iface ens6 inet static
   address 82.165.34.29/32
  netmask 255.255.255.255
  gateway 82.165.34.1
  
  auto ens6:0
  allow-hotplug ens6:0
  iface ens6:0 inet static
   address 195.20.236.17/32

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

• Perform a reboot of the server.

• To verify that the additional IP address is configured correctly, type the following command:

  root@debian:~# ip addr

  The additional public IPv4 address is then displayed. Example:

  root@A34C022:~# ip addr
  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
      link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
      inet 127.0.0.1/8 scope host lo
         valid_lft forever preferred_lft forever
      inet6 ::1/128 scope host
         valid_lft forever preferred_lft forever
  2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
      link/ether ac:1f:6b:9b:22:44 brd ff:ff:ff:ff:ff:ff
      inet 217.160.244.147/32 scope global dynamic eth0
         valid_lft 42230sec preferred_lft 42230sec
      inet 82.165.248.54/32 brd 82.165.248.255 scope global eth0:0
         valid_lft forever preferred_lft forever
      inet6 2001:8d8:1800:1a1::1/128 scope global
         valid_lft forever preferred_lft forever
      inet6 fe80::ae1f:6bff:fe9b:2244/64 scope link
         valid_lft forever preferred_lft forever
  3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
      link/ether ac:1f:6b:9b:22:45 brd ff:ff:ff:ff:ff:ff