public static NetworkInterface GetBestNetworkInterface()
{
var publicIpAddress = new IPAddress(0x08080808); // Googles DNS IP of 8.8.8.8 (Seems like a relatively safe hardcoded IP to pick :))
var ipv4AddressAsUInt32 = BitConverter.ToUInt32(publicIpAddress.GetAddressBytes(), 0);
uint interfaceindex;
var result = Win32ApiCalls.GetBestInterface(ipv4AddressAsUInt32, out interfaceindex);
if (result != 0)
{
throw new Win32Exception(result);
}
var networkCards = NetworkInterface.GetAllNetworkInterfaces().Where(x => x.OperationalStatus == OperationalStatus.Up);
return(networkCards.FirstOrDefault(networkInterface => networkInterface.GetIPProperties().GetIPv4Properties().Index == interfaceindex));
}
public static byte[] GetMacAddress(IPAddress address)
{
byte[] mac = new byte[6];
uint len = (uint)mac.Length;
byte[] addressBytes = address.GetAddressBytes();
uint dest = ((uint)addressBytes[3] << 24)
+ ((uint)addressBytes[2] << 16)
+ ((uint)addressBytes[1] << 8)
+ ((uint)addressBytes[0]);
if (Win32ApiCalls.SendARP(dest, 0, mac, ref len) != 0)
{
throw new Exception("The ARP request failed.");
}
return(mac);
}