result = IpPacketFilter.PfCreateInterface(0, PFFORWARD_ACTION.PF_ACTION_FORWARD, PFFORWARD_ACTION.PF_ACTION_FORWARD, FALSE, TRUE, ref interfaceHandle);

2: PfBindInterfaceToIPAddress

result = IpPacketFilter.PfCreateInterface(0, PFFORWARD_ACTION.PF_ACTION_FORWARD, PFFORWARD_ACTION.PF_ACTION_FORWARD, FALSE, TRUE, ref interfaceHandle);

3: PfCreateInterface

Summary

The PfCreateInterface function creates a new filter interface. Use this interface to control the adding and deleting of filters to and from network adapters.

[DllImport("Iphlpapi.dll", EntryPoint = "PfCreateInterface")]

static extern Int32 PfCreateInterface(int dwName, uint inAction, uint outAction, int bUseLog, int bMustBeUnique, ref IntPtr ppInterface);

Declare Function PfCreateInterface Lib "iphlpapi.dll" (TODO) As TODO

/// The PfCreateInterface function creates a new filter interface. Use this interface to control the adding and deleting of filters to and from adapters.

result = IpPacketFilter.PfCreateInterface(0, PFFORWARD_ACTION.PF_ACTION_FORWARD, PFFORWARD_ACTION.PF_ACTION_FORWARD, FALSE, TRUE, ref interfaceHandle);

Documentation

[PfCreateInterface] on MSDN: http://msdn.microsoft.com/en-us/library/aa376635(VS.85).aspx

4: PfDeleteInterface

Summary

The PfDeleteInterface function deletes an interface that was previously created using PfCreateInterface.

/// The PfDeleteInterface function deletes an interface that was previously created using PfCreateInterface.

/// <param name="pInterface">[in] Specifies an interface handle obtained from a previous call to PfCreateInterface.</param>

Access PInvoke.net directly from VS: