Static IP

Add to /etc/network/interfaces something like this:

auto eth0
  iface eth0 inet static
        address 167.156.160.108
        netmask 255.255.252.0
        gateway 167.156.160.1

To check for the proper gateway from some machine already connected to the network:

$ netstat -r -n

To check for DNS servers from some machine already connected to the network:

cat /etc/resolv.conf

Copy and paste the contents of that file in your own /etc/resolv.conf. Finally (Debian):

# /etc/init.d/networking restart