Secure dhcp

Hi to all,
I have dhcp server on ether1 and I have arp list. But sometimes I see foreign IP and macs at the dhcp server leases list. How can only let the arp list connect from dhcp ? I only want the known mac addresses take ip from microtik.How can I do that ?

Ether1 - arp reply only. Dhcp address list: static only. Create static leases for known macs.

Thank you :slight_smile: