etc network interfaces
$ cat /etc/network/intefaces
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto eth1
iface eth1 inet static
address 192.168.11.100
netmask 255.255.255.0
gateway 192.168.11.1
#if using resolvconf
dns-nameservers 12.34.56.78 12.34.56.79