To setup a static IP in debian edit the file:
/etc/networking/interfaces
# The loopback interface
auto lo
iface lo inet loopback
# The first network card - this entry was created during the Debian installation
# (network, broadcast and gateway are optional)
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
In this case the IP of the server is 192.168.1.100, defined by the setting “address”
To apply this configuration type /etc/init.d/networking restart
You’ll get a message that it’s restarting the network interface, If your connected remotely via shell, you might get disconnected sinc you changed the ip address.
also, make sure the necessary DNS settings are changed in the /etc/resolve.conf