Adding extra IP addresses to Debian

I was just asked to add a new IP address to a Debian cloud host. It’s a simple thing, but depending on how often – or how seldom – you do it, you often still need to look it up to remind yourself. So, having previously decided to do a post every time I do something like this (for my own benefit as much as anything) here’s what I did…

Edit `/etc/network/interfaces` – obviously you’ll need to be root or `sudo` it.

There will probably something like this in there:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

The first chunk is the [loopback interface](, but the second chunk is the ethernet (`eth0`). The final line might be `dhcp` or it might be `static`, followed by more lines to describe the IP, like this:

iface eth0 inet static

To add a new IP – let’s imagine it’s ‘’ – to the same ethernet interface, just add something like this:

iface eth0:0 inet static

The “`:0`” is the extra bit we added. Then restart your networking:

/etc/init.d/networking restart

(keeping your fingers crossed you didn’t make any mistakes that might then lock you out of your host completely, of course ;)