ZyXEL Communications FMG3024-D10A ユーザーズマニュアル

Chapter 10 Network Address Translation (NAT)

FMG3024-D10A / FMG3025-D10A Series User’s Guide

See 

 for advanced technical information on NAT.

Use the Port Forwarding screen to forward incoming service requests to the server(s) on your 
local network.

You may enter a single port number or a range of port numbers to be forwarded, and the local IP 
address of the desired server. The port number identifies a service; for example, web service is on 
port 80 and FTP on port 21. In some cases, such as for unknown services or where one server can 
support more than one service (for example both FTP and web service), it might be better to 
specify a range of port numbers. You can allocate a server IP address that corresponds to a port or 
a range of ports.

The most often used port numbers and services are shown in 

. Please refer 

to RFC 1700 for further information about port numbers. 

Note: Many residential broadband ISP accounts do not allow you to run any server 

processes (such as a Web or FTP server) from your location. Your ISP may 

periodically check for servers and may suspend your account if it discovers any 

active services at your location. If you are unsure, refer to your ISP.

Let's say you want to assign ports 21-25 to one FTP, Telnet and SMTP server (A in the example), 
port 80 to another (B in the example) and assign a default server IP address of 10.0.0.35 to a third 
(C in the example). You assign the LAN IP addresses and the ISP assigns the WAN IP address. The 
NAT network appears as a single host on the Internet.

Multiple Servers Behind NAT Example

Click Network Setting > NAT to open the Port Forwarding screen.

See 

 for port numbers commonly used for particular services. 

A=10.0.0.33

D=10.0.0.36

C=10.0.0.35

B=10.0.0.34