u nas v siti verejky take NATuji 1, pouzivame v3.13 a funguje to jak ma
staci jednoduche pravidlo
/ip firewall nat
add action=netmap chain=dstnat comment="NAT 1:1 - Klient xy" disabled=no dst-address=verejnaIP to-addresses=IPklienta
add action=netmap chain=srcnat comment="" disabled=no src-address=IPklienta to-addresses=verejnaIP
ted uz jen musis presvedcit zakaznika aby si nepral IP "primo" ve svem PC ;)