Linux add a second IP address, permanent or temporary

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Date: 2013-05-24 17:11:11 00:00

Add a secondary IP to Linux

Add a second temporary IP address

Using ifconfig

If you want to add a secondary IP address to a NIC already in use in Linux, and have that change only temporary. Enter this command:

ifconfig [nic]:0 [IP-Address] netmask [mask] up

An example is shown below

ifconfig eth0:0 netmask up

You need to be root in order to execute that command.

Using ip command

If you prefer to use the ip command instead of ifconfig

ip address add [ip]/[mask-digits] dev [nic]

Here is an example

ip address add dev eth0

With this command you can add more ip address to the same dev NIC, the second is considered as secondary.

Add a permanent IP address


For Ubuntu systems, edit the /etc/network/interfaces file

vim /etc/network/interfaces

Add this for one extra IP

auto [NIC]:[n]
iface [NIC]:[n] inet static
address []
gateway []
netmask []

Here an example:

auto eth0:1
iface eth0:1 inet static

You can add as many blocks as you want. Just change eth0:1 for eth0:2, eth0:3 and so on.

If you are adding additional IPs to eth1, or eth2 also modify that on the example.