drop an ip class with iptables

[sde]

i'm running debian woody. i try to use iptables with this command:

# iptables -I INPUT -s 1.2.3.4 -j DROP

and i get this erorr:

modprobe: Can't locate module ip_tables
iptables v1.2.6a: can't initialize iptables table `filter': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

i have removed and re-installed iptables.

any other ideas how i can fix this? also, the command to drop an entire class of ips?

[redhead]

Create a kernel with iptable support.

To your second question:

~> iptables -A INPUT -s 198.168.0.0 -p tcp -j DROP