NETGEAR UTM5EW-100NAS, STM150EW-100NAS manual Configure Network Address Translation, 562

ProSecure Unified Threat Management (UTM) Appliance

•Primary WAN mode. The DSL interface (or a WAN interface or the USB interface) is made the primary interface. The other interfaces are disabled.

•Auto-rollover mode. A DSL or WAN interface is defined as the primary link, and another interface needs to be defined as the rollover link. Because there can be four interfaces on the UTM9S and UTM25S (one DSL, one USB, and two WAN interfaces), the remaining interface are disabled. (If a 3G/4G dongle is installed, you cannot configure the USB interface as the primary link in an auto-rollover configuration, but you can configure it as the rollover link.)

As long as the primary link is up, all traffic is sent over the primary link. When the primary link goes down, the rollover link is brought up to send the traffic. When the primary link comes back up, traffic automatically rolls back to the original primary link.

If you want to use a redundant ISP link for backup purposes, select the DSL or WAN interface that needs to function as the primary link for this mode. Ensure that the backup interface has also been configured and that you configure the WAN failure detection method on the WAN Advanced Options screen to support auto-rollover (see Configure Auto-Rollover Mode and the Failure Detection Method on page 563).

Whichever WAN mode you select, you also need to select either NAT or classical routing, as explained in the following sections.

WARNING:

When you change the WAN mode, the WAN interface or interfaces restart. If you change from primary WAN mode to load balancing mode, or the other way around, the interface through which you can access the UTM9S or UTM25S might change. Take note of the IP addresses of the interfaces before you change the WAN mode.

Configure Network Address Translation

Network Address Translation (NAT) allows all computers on your LAN to share a single public Internet IP address. From the Internet, there is only a single device (the UTM9S or UTM25S) and a single IP address. Computers on your LAN can use any private IP address range, and these IP addresses are not visible from the Internet.

Note the following about NAT:

•The UTM9S or UTM25S uses NAT to select the correct computer (on your LAN) to receive any incoming data.

•If you have only a single public Internet IP address, you need to use NAT (the default setting).

•If your ISP has provided you with multiple public IP addresses, you can use one address as the primary shared address for Internet access by your computers, and you can map incoming traffic on the other public IP addresses to specific computers on your LAN. This one-to-one inbound mapping is configured using an inbound firewall rule.

xDSL Network Module for the UTM9S and UTM25S

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