The EnableRouter function turns on IPv4 forwarding on the local computer. EnableRouter also increments a reference count that tracks the number of requests to enable IPv4 forwarding.

static extern int EnableRouter(IntPtr pHandle, ref System.Threading.NativeOverlapped pOverlapped);

Public Shared Function EnableRouter(pHandle As IntPtr, ByRef pOverlapped As OVERLAPPED) As Integer

Private pOverlapped As OVERLAPPED ' <- Important! This should also be used when calling UnenableRouter() API Function.

pOverlapped.hEvent = CreateEvent(IntPtr.Zero, False, False, "enablerouter")

Dim RetVal As Integer = EnableRouter(IntPtr.Zero, pOverlapped)

Documentation

[EnableRouter] on MSDN

2: UnenableRouter

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.

static extern int UnenableRouter(ref System.Threading.NativeOverlapped pOverlapped, IntPtr lpdwEnableCount);

Public Shared Function UnenableRouter(pOverlapped As IntPtr, ByRef lpdwEnableCount As Long) As Integer

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

RetVal = UnenableRouter(pOverlappedPtr, count)

Documentation

[UnenableRouter] on MSDN

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