How to enable routing among network adapters

Share this:

In this Tutorial we will show how to enable routing among network adapters in Windows Server 2012 R2 although the same procedure can be used on previous versions of the Windows Server system.

For Exchange Administrator in special this procedure can be a sloppy workaround to create sites to test the HA and DR scenarios.


By default routing is not enabled among network adapters and we are going to use the following scenario being shown in the figure below. We have the Toronto site which has the tordc01 server and the Las Vegas site which has the server LASfs01. There is a third server called router which is the focus of this Tutorial and this server has an adapter on each network (Toronto and Las Vegas.

The default gateway for TORDC01  is a router that is not important for us, and the default gateway for LASfs01 is going to be the


Validating TORdc01 server..

Let’s check the configuration on TORDC01 first, the server has the and the default gateway is


The same server has a static route to the network pointing out to the router server interface on the same segment.


If we try to ping a server in Las Vegas we will not be able to as shown in the figure below.


Validating LASfs01 server..

In this server the configuration is simpler, the default gateway points out to the network card in the router server.


However, if we try a ping from that server we still have the issue, as follows.


Enabling routing..

The router server has several network adapters as shown in the figure below. The network adapters are named based on the sites that they are connectes (Las Vegas and Toronto)


The solution is simple, open regedit on the server and navigate to the HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesTcpipParameters  and change the value of  IPEnableRouter to 1.


Validating the routing…

Now that we have the routing in place, we can perform the same ping test and it will work just fine from Toronto site.


The same test can be performed from Las Vegas and the results are going to be positive.



In this Tutorial we demonstrated how to enable IP routing in Windows Server 2012 R2 to enable routing among network interfaces in a server.

Written by Anderson Patricio

Anderson Patricio is a Canadian Exchange Server MVP and MCSM (Solutions Master) and he contributes to the Microsoft Community with articles, tutorials, blog posts, forums and book reviews. He is a regular contributor at, and (Portuguese).