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Extra ip address configuration

Last updated on Sep 24, 2025

For extra IPs to work, you must configure them inside the operating system of the server you use.

To temporarily configure an IPv4 “1.2.3.4”, you can run:

ip addr add 1.2.3.4/32 dev eth0

Please note that this configuration will not survive a reboot.

To configure the first IPv6 address of an IPv6 netblock 2a01:4f8:2c17:2c::/64, you should run:

ip addr add 2a01:4f8:2c17:2c::1/128 dev eth0

How do i permanently configure an extra IP?

On Debian based distributions (Ubuntu versions before 20.04, Debian):

  1. Access the server via SSH.

  2. Create the configuration file and open an editor:

touch /etc/network/interfaces.d/60-my-extra-ip.cfg
nano /etc/network/interfaces.d/60-my-extra-ip.cfg

  1.  Paste the following configuration into the editor and replace your.Extra.IP with your extra IP:

IPv4:

auto eth0:1
 iface eth0:1 inet static
     address your.Extra.IP
     netmask 32

IPv6:

auto eth0:1
 iface eth0:1 inet6 static
     address one IPv6 address of the subnet, e.g. 2a01:4f9:0:2a1::2
     netmask 64
  1. Now you should restart your network. Caution: This will reset your network connection:
sudo service networking restart

Ubuntu 20.04:

  1. Access the server via SSH.

  2. Create the configuration file and open an editor:

touch /etc/netplan/60-extra-ip.yaml
nano /etc/netplan/60-extra-ip.yaml

  1. Paste the following configuration into the editor and replace your.Extra.IP with your extra IP:

IPv4:

network:
   version: 2
   renderer: networkd
   ethernets:
     eth0:
       addresses:
       - your.extra.ip/32

IPv6:

network:
   version: 2
   renderer: networkd
   ethernets:
     eth0:
       addresses:
       - your.extra.ip/64
  1. Now you should restart your network. Caution: This will reset your network connection:
sudo netplan apply

On RHEL based distributions (Fedora, CentOS):

  1. Access the server via SSH.

  2. Create the configuration file and open an editor:

touch /etc/sysconfig/network-scripts/ifcfg-eth0:1
vi /etc/sysconfig/network-scripts/ifcfg-eth0:1

  1.  Paste the following configuration into the editor and replace your.Extra.IP with your extra IP:

IPv4:

BOOTPROTO=static
DEVICE=eth0:1
IPADDR=your.Extra.IP
PREFIX=32
TYPE=Ethernet
USERCTL=no
ONBOOT=yes

IPv6:

BOOTPROTO=none
DEVICE=eth0:1
ONBOOT=yes
IPV6ADDR=one IPv6 address of the subnet, e.g. 2a01:4f9:0:2a1::2/64
IPV6INIT=yes
  1. Now you should restart your network. Caution: This will reset your network connection:
systemctl restart network