/ip firewall nat

add action=same chain=srcnat comment=\
    "SRC-NAT dinamico con un pool de 4 IPs de CABLETEL SA" \
    same-not-by-dst=yes disabled=no dst-address-list=!REDES-LOCALES \
    dst-address-type=!local out-interface=ether1-WAN src-address-list=\
    SALEN-X-CABLETEL to-addresses=190.211.64.203-190.211.64.206