sudo nano /etc/network/interfaces
and there
auto lo eth0
iface lo inet loopback
iface eth0 inet static
address 192.168.1.101
netmask 255.255.255.0
gateway 192.168.1.1
If you are using ubuntu 14.04, you may find you can not setting dns on your /etc/resolv.conf
This is because ubuntu using resolvconf to manage the dns setting, every times system boot, resolvconf will regenerate resolv.conf file.
But there always have way to do this.
sudo gedit /etc/resolvconf/resolv.conf.d/base put your nameserver list in
nameserver 8.8.8.8
nameserver 8.8.4.4
then run
resolvconf -u
this command tell resolvconf to regenerate the resolve file