How to block Multi mac ?

How can i block multi mac addresses on Mikrotik?

some users change there mac address to allow Mac. then they can use net easily. i want to get rid from that hackers.

wireless or wired network?

i have both. and need this solution for both network. so that no one can misuse my services.

maybe you can make all mac addresses in arp static and then the interface that your users are connected to put it arp=reply-only

hope this helped you..