Block ip range using iptables in Ubuntu 9.04

[UbuntU-ME]

I have hosted a small web server for our lan. The problem is our ISP is WiMAX and all the customers can access anything on the network no wonder where you stay [geographic location]. I have heard the in ubuntu 9.04 you can block ip range using iptables. But i don't know how to do it. Can anyone help me with this? Thanks in advance...

[FaMe FacToR]

Have a look at these threads, may be they could help :
How can I block or ban Ip address range?
Block the entire range of IP address in Linux using hosts.deny
How to Filter Mac Address Using Iptables ?
If you still have difficulties, do post back...

[Solomon]

Suppose you want to block an IP address range starting from 192 and the ip is 192.168.32.55, type this in console :

sbin/iptables -I INPUT -s 192.0.0.0/255.0.0.0 -j DROP

This will block all the IP address from 192.0.0.0 to 192.255.255.255

[Devasis]

You can add the to be banned IP to the iptable files whose location is : "/etc/sysconfig/iptables". Add the IP address(es) to be banned/blocked... Hope this helps you...