Different IP addresses

Hi, I have a WI-FI connection with freeRADIUS+OpenLDAP+Chillispot. I have to manage two groups of people. The first group have hit to all the resources of the LAN, the second group can use only the http protocol. There is a simple solution to do this? I have thinked to assign some different IP class to each group, and manage the rule with iptables. If this is the only solution, how i can assign different IP classes? Best regards. Giusy