now when you open interfaces you will see something like this:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).# The loopback network interface
auto lo
iface lo inte loopback#The primary network interface
auto eth0
iface eth0 inet dhcp
# and how to activate them. For more information, see interfaces(5).# The loopback network interface
auto lo
iface lo inte loopback#The primary network interface
auto eth0
iface eth0 inet dhcp
now to change it to a static ip change the file to look like this for example:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inte loopback
#The primary network interface
auto eth0
iface eth0 inet static
address 192.168.0.101
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1