DHCP
auto eth0 iface eth0 inet dhcp
Static IP
auto eth0 iface eth0 inet static address 192.168.1.100 netmask 255.255.255.0 network 192.168.1.0 broadcast 192.168.1.255 gateway 192.168.1.1
Restart the network
sudo /etc/init.d/networking restart
DHCP
auto eth0 iface eth0 inet dhcp
Static IP
auto eth0 iface eth0 inet static address 192.168.1.100 netmask 255.255.255.0 network 192.168.1.0 broadcast 192.168.1.255 gateway 192.168.1.1
Restart the network
sudo /etc/init.d/networking restart