Vigor routers support three variants of port mapping methods.
Port redirection – The packet is forwarded onto a specific local PC with the specified port number. You can also translate the port to another local port.
Open Port – As Port Redirection (described above) but allows you to define a range of ports.
DMZ Host – This opens up a single PC completely. All incoming packets will be forwarded onto the PC in the DMZ. The only exceptions are packets received in response to outgoing requests from other local PC’s or incoming packets which match rules in the other two methods.
When using combinations of these three methods, there is a priority structure. i.e. if a rule in one method coincides with a rule in another method, then there is strict precedence. The precedence is as follows:
Port Redirection -> Open Port -> DMZ