Enable IP Forwarding Between Subnets

Updated: June 09, 2001
By Berry Schreuder, e-office, Utrecht, The Netherlands

Here is my tip for Windows 2000 Server. I found out about this while I was evaluating Windows 2000 Server in a test lab.

Suppose you are testing site replication and wish to have multiple Internet Protocol (IP) subnets without having to install routers or Routing and Remote Access Services.

Here's a quick trick to enable IP forwarding:

In the Registry, set the value IPEnableRouter in HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Tcpip \Parameters to 0x00000001.

This enables routing between the two subnets. Consider, though, that this is not safe when routing between public networks. Remember to set your default gateways!