Linux, Hosting tips

The IP configurations on Debian are stored in /etc/network/interfaces. Below is an example that will configure the device eth0 to have an IP address of 192.168.1.100 on a class C network with 192.168.1.1 as the default gateway.

vim /etc/network/interfaces

The file will look like the following.

# /etc/network/interfaces – configuration file for ifup(8), ifdown(8)
# the loopback interface
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static

address 192.168.1.100
netmask 255.255.255.0
broadcast 192.168.1.255
gateway 192.168.1.1

In order to assign multiple IP addresses on the same interface (say eth0), add the following. The below example will add three more IP addresses to the same interface:

auto eth0:0
iface eth0:0 inet static

address 192.168.1.101
netmask 255.255.255.0
broadcast 192.168.1.255

auto eth0:1
iface eth0:1 inet static

address 192.168.1.102
netmask 255.255.255.0
broadcast 192.168.1.255

auto eth0:2
iface eth0:2 inet static

address 192.168.1.103
netmask 255.255.255.0
broadcast 192.168.1.255

To update your IP configuration after saving to /etc/network/interface, execute the command,

# /etc/init.d/networking restart

Make sure to double-check your configuration as this could make your server unreachable if there are any errors.