Block static IPs

Hello,

I have a simple internet distribution network. I have configured all PCs to be DHCP clients. I have configured Mikrotik DHCP Server with static only leases using PCs MAC Address as a verification.

The problem is sometimes users cheat me and use static IPs in the range. Is there a way to allow only PCs with IP addresses taken from Mikrotik DHCP server? and block those who use static IPs ??

Thanks all.

http://wiki.mikrotik.com/wiki/How_to_Block_Customer