IP Routing Requires two NICs
By default, IP routing is disabled. To enable IP routing, you must allow the computer to
forward IP packets it receives. This requires a change to the Windows 2000 system registry.
When you enable the Routing and Remote Access service for IP routing, this registry entry
is made automatically.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
"IPEnableRouter"=1
It is required to reboot Windows 2000 for this change to take effect.
I have used this in a configuration, where the Windows 2000 Professional system works
as a router between an Ethernet network and a USB-network.