Systems that use server versions of Windows operating systems can forward IP packets that are not addressed to them. These systems, and Windows Vista and Windows 7 and later systems, have IP packet forwarding disabled by default.

If packets are leaking from a host-only network on a Windows host system, check whether packet forwarding is enabled on the host system. If packet forwarding is enabled, you must disable it.

Procedure

On a Windows Vista or Windows 7 or later host, stop the Routing and Remote Access service.
  1. Type services.msc to open the Services Console.
  2. Select Routing and Remote Access and click Stop.