private bool IsMulticast() { if (MulticastMode == MulticastMode.Auto) { // 224.0.0.0 to 239.255.255.255 are multicast (https://en.wikipedia.org/wiki/Multicast_address) byte firstByte = RemoteAddress.GetAddressBytes()[0]; return(firstByte >= 224 && firstByte < 240); } else { return(MulticastMode == MulticastMode.Enabled); } }