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 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.


IP forwarding is not a problem on Windows XP Professional or Windows XP Home Edition host systems.

On a Windows Vista or Windows 7 host, stop the Routing and Remote Access service.


Type services.msc to open the Services Console.


Select Routing and Remote Access and click Stop.

On a Windows 2003 Server host, use Windows Administrative Tools to disable routing and remote access.


Select Start > Programs > Administrative Tools > Routing and Remote Access.

An icon on the left is labeled with the host name. If a green dot appears over the icon, IP forwarding is turned on.


To turn off IP forwarding, right-click the icon and disable Routing and Remote Access.

A red dot appears, indicating that IP forwarding is disabled.