ZyXEL UAG4100 User Guide - Page 223

Chapter 14 NAT Table 97 Configuration > Network > NAT > Add (continued) LABEL Port Mapping Type DESCRIPTION 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. Service - this NAT rule supports the destination port(s) used by the specified service(s). 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. Original Service Mapped Service Protocol Type Original Port Mapped Port Original Start Port Original End Port Mapped Start Port Mapped End Port Enable NAT Loopback This field is read-only and displays any for Many 1:1 NAT. This field is available if Port Mapping Type is Service. Select the original service whose destination port(s) is supported by this NAT rule. This field is available if Port Mapping Type is Service. Select the translated service whose destination port(s) is supported if this NAT rule forwards the packet. This field is available if Port 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 Port Mapping Type is Port. Enter the original destination port this NAT rule supports. This field is available if Port Mapping Type is Port. Enter the translated destination port if this NAT rule forwards the packet. This field is available if Port Mapping Type is Ports. Enter the beginning of the range of original destination ports this NAT rule supports. This field is available if Port Mapping Type is Ports. Enter the end of the range of original destination ports this NAT rule supports. This field is available if Port 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 Port 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 UAG 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 UAG 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 224 for more details. Security Policy If you do not enable NAT loopback, this NAT rule only applies to packets received on the rule's specified incoming interface. By default the Security Policy blocks incoming connections from external addresses. After you configure your NAT rule settings, click the Security Policy link to configure a security policy to allow the NAT rule's traffic to come in. OK Cancel The UAG checks NAT rules before it applies To-Device security policies, so To-Device security policies do not apply to traffic that is forwarded by NAT rules. The UAG still checks other security policies according to the source IP address and mapped IP address. Click OK to save your changes back to the UAG. Click Cancel to return to the NAT summary screen without creating the NAT rule (if it is new) or saving any changes (if it already exists). UAG Series User's Guide 223