private static int GetBestInterfaceForAddress(IPAddress addr)
{
int index;
SocketAddress address = new SocketAddress(addr);
int error = (int)UnsafeNetInfoNativeMethods.GetBestInterfaceEx(address.m_Buffer, out index);
if (error != 0)
{
throw new NetworkInformationException(error);
}
return(index);
}