ZyXEL g-2000 plusv2 Guia Do Utilizador

ZyXEL G-2000 Plus v2 User’s Guide

Chapter 8 Single User Account (SUA) / Network Address Translation (NAT)

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Some services use a dedicated range of ports on the client side and a dedicated range of ports 
on the server side. With regular port forwarding you set a forwarding port in NAT to forward a 
service (coming in from the server on the WAN) to the IP address of a computer on the client 
side (LAN). The problem is that port forwarding only forwards a service to a single LAN IP 
address. In order to use the same service on a different LAN computer, you have to manually 
replace the LAN computer's IP address in the forwarding port with another LAN computer's IP 
address, 

Trigger port forwarding solves this problem by allowing computers on the LAN to 
dynamically take turns using the service. The ZyXEL device records the IP address of a LAN 
computer that sends traffic to the WAN to request a service with a specific port number and 
protocol (a "trigger" port). When the ZyXEL device's WAN port receives a response with a 
specific port number and protocol ("incoming" port), the ZyXEL device forwards the traffic to 
the LAN IP address of the computer that sent the request. After that computer’s connection for 
that service closes, another computer on the LAN can use the service in the same manner. This 
way you do not need to configure a new IP address each time you want a different LAN 
computer to use the application.

Table 43   Address Mapping Edit

Type

Choose the port mapping type from one of the following. 
1. One-to-One: One-to-one mode maps one local IP address to one global IP 

address. Note that port numbers do not change for One-to-one NAT mapping 

type.
2. Many-to-One: Many-to-One mode maps multiple local IP addresses to one 

global IP address. This is equivalent to SUA (i.e., PAT, port address translation), 

ZyXEL device's Single User Account feature. 
3. Many-to-Many Overload: Many-to-Many Overload mode maps multiple local 

IP addresses to shared global IP addresses. 
4. Many One-to-One: Many One-to-one mode maps each local IP address to 

unique global IP addresses. 
5. Server: This type allows you to specify inside servers of different services 

behind the NAT to be accessible to the outside world.

Local Start IP

This is the starting Inside Local IP Address (ILA). Local IP addresses are N/A for 

Server port mapping.

Local End IP

This is the end Inside Local IP Address (ILA). If your rule is for all local IP 

addresses, then enter 0.0.0.0 as the Local Start IP address and 

255.255.255.255 as the Local End IP address. 
This field is N/A for One-to-One and Server mapping types.

Global Start IP

This is the starting Inside Global IP Address (IGA). Enter 0.0.0.0 here if you have 

a dynamic IP address from your ISP. 

Global End IP

This is the ending Inside Global IP Address (IGA). This field is N/A for One-to-

One, Many-to-One and Server mapping types.

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