The configuration of NAT in Windows 2000 is handled via Routing and Remote Access. Although the service is installed by default, it usually will not be enabled. If the service is not prese nt on your system, it can be added via Windows Components in the Add/Remove programs applet in Control Panel.
The first step in the configuration process is to open the RRAS Administrative Tool, right-click on your server in the console, and choosing to enable and configure routing and remote access. This will launch the RRAS configuration wizard, with the choices shown below. For the purpose of this configuration, I’m choosing the manually configured server option, just in case some of you already have RRAS running on your server.
After choosing the manual option and exiting the wizard, the RRAS service will start.
In order to configure NAT, you’ll need to expand the IP Routing section, and oddly, right click on the General item (this is obviously an interface error, you should rightly need to right click on IP Routing). From the shortcut menu, choose New Routing Protocol.
From the New Routing Protocol tab that opens, choose the Network Address Translation option, and press OK. This will add NAT to the interface, under the IP Routing parent item. At this point, all you have done is enabled the ability to configure NAT. Until interfaces are configured, your NAT server will still not do anything NAT-like. Right click on Network Address Translation and choose the New Interface option.
The interface will present you with a list of interfaces available on the system. To begin, choose the interface that you intend to use as your internal interface (in reality, it doesn’t matter whether you configure the internal or external interface first, but I had to start somewhere). This will present the NAT Properties dialog box.
The internal interface lacks much in the way of configurable elements – in fact, you simply designate it as the private interface and nothing more. After pressing OK, repeat the New Interface process, and add your second interface – this one will act as the external interface connected to the public Internet.