ZyWALL 2WG Support Notes
All contents copyright (c) 2006 ZyXEL Communications Corporation. 28
5. Server
In Server mode, the ZyWALL maps multiple inside servers to one global IP address. This allows us to
specify multiple servers of different types behind the NAT for outside access. Note, if you want to map
each server to one unique IGA please use the One-to-One mode.
The following table summarizes these types.
NAT Type IP Mapping
One-to-One ILA1<--->IGA1
Many-to-One
(SUA/PAT)
ILA1<--->IGA1
ILA2<--->IGA1
...
Many-to-Many
Overload
ILA1<--->IGA1
ILA2<--->IGA2
ILA3<--->IGA1
ILA4<--->IGA2
...
Many One-to-One
ILA1<--->IGA1
ILA2<--->IGA2
ILA3<--->IGA3
ILA4<--->IGA4
...
Server Server 1 IP<--->IGA1
Server 2 IP<--->IGA1
• SUA Versus Multi-NAT
SUA (Single User Account), if you get only one public IP address from your ISP, then you should use SUA.
With SUA, PCs on ZyWALL's LAN side can access Internet without further configuration. If you have internal
servers to be accessed by remote users on Internet, you need to go to ADVANCED -> SUA/NAT -> SUA
Server to setup which service, or port numbers, you would like to forward to which Internal server.
Multi-NAT, if you get multiple public IP addresses from your ISP, then you may use Multi-NAT. With
Multi-NAT, you can choose different types of NAT mapping methods to utilize the public IP addresses. You
should define each NAT mapping rules clearly in ADVANCED -> SUA/NAT -> Address Mapping, so that
internal PCs can access Internet and internal servers can be accessed by remote uses on Internet.