[Ubuntu] How to setup network interface

You can modify the interface script which is /etc/network/interfaces

In case you want to set static IP, example

$ cat /etc/network/interfaces

auto lo

iface lo inet loopback

auto eth0

iface eth0 inet static

address 203.237.53.112

netmask 255.255.255.0

gateway 203.237.53.254

in command line, it has the same effect of

$ sudo ifconfig eth0 203.237.53.112/24

$ sudo route add default gw 203.237.53.254

In case you want to set DHCP

$ cat /etc/network/interfaces

auto lo

iface lo inet loopback

auto eth0

iface eth0 inet dhcp

in command line, it has the same effect as follows

$ sudo dhclient eth0