本篇記錄我查到關於居易的NAT及DMZ相關說明，
我用Goolge翻譯播成中文再稍微調一下。

居易的NAT有「連接埠重定向」、「開放連接埠」和 「DMZ 主機」。
(There are Port Redirection, Open Ports, and DMZ Host.)

Port Redirection - The packet with the specified port number.is forwarded onto a specific LAN host  You can also translate the port to another local port. 
連接埠重定向 - 具有指定連接埠號的封包被轉送到特定的 區網主機您也可以將該連接埠轉換為另一個本地端連接埠。

Open Ports - It is the same as Port Redirection (described above) but allows you to define a range of ports. 
開放連接埠 - 它與連接埠重定向（如上所述）相同，但允許您定義一個範圍的多個連接埠。

DMZ Host - This opens up a single host to the Internet completely. All incoming packets will be forwarded to the DMZ host, Except packets received in response to outgoing requests from other LAN host or incoming packets which match the rules of Port Redirection and Open Ports. 
DMZ 主機 - 這會將單個主機完全打開到 網際網路。所有傳入的封包都將被轉發到 DMZ 主機，但不包括反應來自其他 LAN 主機的傳出請求及匹配的「連接埠重定向」和「開放連接埠」規則的傳入封包。

When using combinations of these three methods, there is a priority structure Port Redirection >> Open Ports >> DMZ. For example, if an Open Ports rule conflicts with a Port Redirection rule, then Port Redirection will take effect. 

當使用這三種方法的組合時，有一個優先級結構「連接埠重定向」大於「開放連接埠」大於「DMZ主機」。 
例如，如果 Open Ports 規則與 Port Redirection 規則衝突，則 Port Redirection 將生效。