
Run the following steps on both IMAGE and DC servers (Windows 2008 R2)
DC server:
Right-Click Routing and Remote Access/Configure and Enable Routing and Remote Access












make sure you have the static route defined.
In DC:

In IMAGE server:
The static route should be 191.121.0.0 255.255.128.0 and Interface is Remote Router.
You can ping the client computer A from client B.