ZyXEL ZyWALL USG 2000 User Guide - Page 392

Chapter 19 NAT Table 98 Configuration > Network > NAT > Add (continued) LABEL DESCRIPTION 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. Protocol Type Original Port Mapped Port Original Start Port Original End Port Mapped Start Port Mapped End Port Enable NAT Loopback See Appendix B on page 959 for some common port numbers. 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. This field is available if Mapping Type is Port. Enter the original destination port this NAT rule supports. This field is available if Mapping Type is Port. Enter the translated destination port if this NAT rule forwards the packet. This field is available if Mapping Type is Ports. Enter the beginning of the range of original destination ports this NAT rule supports. This field is available if Mapping Type is Ports. Enter the end of the range of original destination ports this NAT rule supports. 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. 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 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 NAT Loopback on page 393 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. 392 ZyWALL USG 2000 User's Guide