ZyXEL Communications 91-009-073003B manual 326

Chapter 17 NAT

Table 93 Configuration > Network > NAT > Add (continued)

LABEL	DESCRIPTION
Mapped IP	This field displays for Many 1:1 NAT. Select to which translated
Subnet/Range	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	Use the drop-down list box to select how many original destination ports
Type	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 Appendix B on page 841 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	This field is available if Mapping Type is Ports. Enter the beginning of
Port	the range of original destination ports this NAT rule supports.
Original End	This field is available if Mapping Type is Ports. Enter the end of the
Port	range of original destination ports this NAT rule supports.
Mapped Start	This field is available if Mapping Type is Ports. Enter the beginning of
Port	the range of translated destination ports if this NAT rule forwards the
	packet.
Mapped End	This field is available if Mapping Type is Ports. Enter the end of the
Port	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	Enable NAT loopback to allow users connected to any interface (instead
Loopback	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 NAT Loopback on page 327 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.

326
	ZyWALL USG 50 User’s Guide