例子
将10.0.0.252的3389端口，映射到外网
其中dst-address-list里面ddns为我设置的域名

/ip firewall nat
add action=masquerade chain=srcnat comment=huiliu out-interface=bridge src-address=10.0.0.0/24
add action=dst-nat chain=dstnat comment=alist dst-address-list=ddns dst-port=5244 protocol=tcp to-addresses=10.0.0.254 to-ports=5244
add action=dst-nat chain=dstnat comment=3389 dst-address-list=ddns dst-port=3389 protocol=tcp to-addresses=10.0.0.252 to-ports=3389
add action=dst-nat chain=dstnat comment=dsm dst-address-list=ddns dst-port=5000 protocol=tcp to-addresses=10.0.0.155 to-ports=5000