IP

/etc/network/interfaces

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 192.168.0.147
    netmask 255.255.255.0
    gateway 192.168.0.1

DNS

/etc/resolv.conf
nameserver 1.1.1.1
nameserver 8.8.8.8