Enabling IP Forwarding on Windows 2000

Scope

This technote refers details how to enable IP forwarding on a Windows 2000 server to allow traffic to be routed once Check Point Firewall-1 is installed.

IP forwarding is disabled by default in a Windows environment, but enable in a Unix environment. In order to get a Check Point Firewall on a Windows 2000 platform, the IP stack must be configured to enable IP forwarding.

Solution

On a Windows NT platform this was simple a question of checking the "Enable IP forwarding" option under the Routing tab of the Microsoft TCP/IP Properties screen.

Under Window 2000, this tab no longer exists and you are required to use REGEDIT to achieve the same end.

1) Start the registry editor (Start > Run > regedit)

2) Choose HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Services > TCPIP > Parameters

3) Modify IPEnableRouter and set the value to "1"

4) Reboot the server

When the server comes back up it will be enabled as a router