auto eth0
iface eth0 inet static
        address 192.168.198.100
        netmask 255.255.255.0
        network 192.168.198.0
        broadcast 192.168.198.255
        gateway 192.168.0.2
and this result

debian:/home/andy# nano /etc/network/interfaces
debian:/home/andy# /etc/init.d/networking restart
Reconfiguring network interfaces...SIOCDELRT: No such process
SIOCADDRT: Network is unreachable
Failed to bring up eth0.
done.