Ubuntu network configuration

auto eth0
iface eth0 inet static
address 10.0.0.100
netmask 255.255.255.0
gateway 10.0.0.1

# The loopback network interface  
auto lo  
iface lo inet loopback  
 
 
# The primary network interface  
auto eth0 
iface eth0 inet static  
address 192.168.X.X
netmask 255.255.255.0
gateway 192.168.X.X
dns-nameservers X.X.X.X 
 
If you have more than one DNS server, just add a space between each:
 
dns-nameservers X.X.X.X Y.Y.Y.Y Z.Z.Z.Z
 
Just replace the X'es with your own IPs and the DNS server of choise, and when this is done, run this command to update the settings:
 
sudo ifdown eth0 && sudo ifup eth0