pinvoke.net: Edit: iphlpapi.UnenableRouter

@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$
@pinvoke=http://pinvoke.net/$$$.htm

Summary: The UnenableRouter function decrements the reference count that tracks the number of requests to enable IPv4 forwarding. When this reference count reaches zero, UnenableRouter turns off IPv4 forwarding on the local computer.

!!!!C# Signature:
 [DllImport("iphlpapi.dll", SetLastError=true)]
 static extern int UnenableRouter(ref System.Threading.NativeOverlapped pOverlapped, IntPtr lpdwEnableCount);
!!!!VB.NET Signature:
    <DllImport("iphlpapi.dll", CharSet:=CharSet.Ansi)>
    Public Shared Function UnenableRouter(pOverlapped As IntPtr, ByRef lpdwEnableCount As Long) As Integer
    End Function
!!!!User-Defined Types:
None.

!!!!Alternative Managed API:
Do you know one?  Please contribute it!

!!!!Notes:
None.

!!!!Tips & Tricks:
Please add some!

!!!!Sample Code:
VB.NET Example

Private Const NO_ERROR As Integer = 0
    <StructLayout(LayoutKind.Explicit, Size:=20)>
    Public Structure OVERLAPPED
        <FieldOffset(0)>
        Public Internal As UInt32
        <FieldOffset(4)>
        Public InternalHigh As UInt32
        <FieldOffset(8)>
        Public Offset As UInt32
        <FieldOffset(12)>
        Public OffsetHigh As UInt32
        <FieldOffset(8)>
        Public Pointer As IntPtr
        <FieldOffset(16)>
        Public hEvent As IntPtr
    End Structure

<DllImport("iphlpapi.dll", CharSet:=CharSet.Ansi)>
    Public Shared Function UnenableRouter(pOverlapped As IntPtr, ByRef lpdwEnableCount As Long) As Integer
    End Function

<DllImport("kernel32.dll")>
    Public Shared Function CloseHandle(ByVal hwn As IntPtr) As Long
    End Function

Private pOverlapped As OVERLAPPED <- Important! Created from EnableRouter() call.

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Dim count As Long
        Dim pOverlappedPtr As IntPtr
        Dim RetVal As Integer
        Dim size As Integer
        Try
            size = Marshal.SizeOf(pOverlapped)
            If pOverlapped.hEvent = IntPtr.Zero Then Exit Sub ' We don't have the handle.
            pOverlappedPtr = Marshal.AllocHGlobal(size)
            Marshal.StructureToPtr(pOverlapped, pOverlappedPtr, True)

RetVal = UnenableRouter(pOverlappedPtr, count)
            If RetVal = NO_ERROR Then
                Console.WriteLine("Success!")
            Else
                Dim errorMessage As String = New Win32Exception(RetVal).Message
                Console.WriteLine(errorMessage)
            End If
            If pOverlappedPtr <> IntPtr.Zero Then CloseHandle(pOverlapped.hEvent)
        Catch ex As Exception
            Console.WriteLine(ex.ToString)
        Finally
            Marshal.FreeHGlobal(pOverlappedPtr)
        End Try
            End Sub

Documentation: UnenableRouter@msdn on MSDN