How to set up additional IP addresses?

Modified on Sat, 14 Sep at 9:36 PM

Network configuration in Debian/Ubuntu

1 # Add an address to the interface. It will be lost after reboot.
2 $ ip addr add 10.1.0.1/24 dev eth0

You can manually specify it in the configuration file:

nano /etc/network/interfaces/interfaces.d/50-cloud-init (For Debian)

# This file is generated from information provided by the datasource. Changes
# so it will not persist across an instance reboot. To disable cloud-init
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
auto lo
iface lo inet loopback
dns-nameservers 8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
dns-search justhost.ru

auto eth0
iface eth0 inet static
  address 192.168.3.10/24
  address 192.168.5.140/24 # Additional IP
gateway 192.168.3.1

# control-alias eth0
iface eth0 inet6 static
  address 2605:e440:1::1:2e6/64
gateway 2605:e440:1::1

After adding the additional IP address on the network interface, save the file with ctrl + X key combination.

And enter the command:

$ systemctl restart networking

An additional IP address has been added to the Debian network interface.

nano /etc/netplan/*.yaml (For Ubuntu)

# This file is generated from information provided by the datasource. Changes
# so it will not persist across an instance reboot. To disable cloud-init
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
version: 2
ethernets:
eth0:
addresses:
- 192.168.3.10/24
- 2605:e440:1::1:23/64
- 192.168.5.140/24 # Additional IP
gateway4: 192.168.3.1
gateway6: 2301:e320:1::1
match:
mac address: 33:24:43:76:2f:11
nameservers:
addresses:
- 8.8.8.8
- 8.8.4.4
- 2001:4860:4860::8888
- 2001:4860:4860::8844
search:
- justhost.ru
set-name: eth0

After adding an additional IP address to the network interface, save the file with the ctrl + X key combination.

You can check the saved settings file with the command:

$ netplan try

Then, if all is well, apply the settings on the fly:

$ netplan apply

Network configuration in CentOS.

1 # Add an address to the interface. It will be lost after reboot.
2 ip addr add 10.1.0.1/24 dev eth0
3 ip -6 addr add 2a00:b700:1::2/64 dev eth0

You can manually specify it in the configuration file. The configuration of network interfaces is stored in /etc/sysconfig/network-scripts/ifcfg-ethX.

X is the number of the physical interface.

Example file /etc/sysconfig/network-scripts/ifcfg-eth0

How to start editing the file: write the command "nano" before the file itself. Example: nano /etc/sysconfig/network-scripts/ifcfg-eth0

Additional addresses (aliases) are configured in the ifcfg-ethX:Y files.

X is the physical interface number, Y is the alias number (numbering from 0).

(ONLY FOR INSTALLING 2,3,4 addresses(and IPV6)! NOT REQUIRED WHEN CONFIGURING A SINGLE IPV6 )

Example file: /etc/sysconfig/network-scripts/ifcfg-eth0:1

How to start editing the file: write the command "nano" before the file itself. Example: nano /etc/sysconfig/network-scripts/ifcfg-eth0:1

DEVICE=eth0:1
BOOTPROTO=static
IPADDR=192.168.3.10
NETMASK=255.255.255.0
ONBOOT=yes

After adding the additional IP address on the network interface, save the file with ctrl + X key combination.

And enter the command:

$ systemctl restart networking