ZyXEL Communications 1000 Manuel D’Utilisation

Chapter 19 NAT

ZyWALL USG 1000 User’s Guide

Mapped IP 
Subnet/Range

This field displays for Many 1:1 NAT. Select to which translated 
destination IP address subnet or IP address range this NAT rule forwards 
packets. The original and mapped IP address subnets or ranges must 
have the same number of IP addresses.

Port Mapping 
Type

Use the drop-down list box to select how many original destination ports 
this NAT rule supports for the selected destination IP address (Original 
IP). Choices are:

Any - this NAT rule supports all the destination ports.

Port - this NAT rule supports one destination port.

Ports - this NAT rule supports a range of destination ports. You might 
use a range of destination ports for unknown services or when one 
server supports more than one service. 

See 

 for some common port numbers.

Protocol Type

This field is available if Mapping Type is Port or Ports. Select the 
protocol (TCP, UDP, or Any) used by the service requesting the 
connection.

Original Port

This field is available if Mapping Type is Port. Enter the original 
destination port this NAT rule supports.

Mapped Port

This field is available if Mapping Type is Port. Enter the translated 
destination port if this NAT rule forwards the packet.

Original Start 
Port

This field is available if Mapping Type is Ports. Enter the beginning of 
the range of original destination ports this NAT rule supports.

Original End 
Port

This field is available if Mapping Type is Ports. Enter the end of the 
range of original destination ports this NAT rule supports.

Mapped Start 
Port

This field is available if Mapping Type is Ports. Enter the beginning of 
the range of translated destination ports if this NAT rule forwards the 
packet.

Mapped End 
Port

This field is available if Mapping Type is Ports. Enter the end of the 
range of translated destination ports if this NAT rule forwards the packet. 
The original port range and the mapped port range must be the same 
size.

Enable NAT 
Loopback

Enable NAT loopback to allow users connected to any interface (instead 
of just the specified Incoming Interface) to use the NAT rule’s 
specified Original IP address to access the Mapped IP device. For 
users connected to the same interface as the Mapped IP device, the 
ZyWALL uses that interface’s IP address as the source address for the 
traffic it sends from the users to the Mapped IP device.

For example, if you configure a NAT rule to forward traffic from the WAN 
to a LAN server, enabling NAT loopback allows users connected to other 
interfaces to also access the server. For LAN users, the ZyWALL uses the 
LAN interface’s IP address as the source address for the traffic it sends 
to the LAN server. See 

 for more details.

If you do not enable NAT loopback, this NAT rule only applies to packets 
received on the rule’s specified incoming interface.

Table 98   Configuration > Network > NAT > Add (continued)