System.Net.Sockets.Socket.SetIPProtectionLevel C# (CSharp) Method

        public void SetIPProtectionLevel(IPProtectionLevel level)
        {
            if (level == IPProtectionLevel.Unspecified)
            {
                throw new ArgumentException(SR.Format(SR.net_sockets_invalid_optionValue_all), nameof(level));
            }

            if (_addressFamily == AddressFamily.InterNetworkV6)
            {
                SocketPal.SetIPProtectionLevel(this, SocketOptionLevel.IPv6, (int)level);
            }
            else if (_addressFamily == AddressFamily.InterNetwork)
            {
                SocketPal.SetIPProtectionLevel(this, SocketOptionLevel.IP, (int)level);
            }
            else
            {
                throw new NotSupportedException(SR.net_invalidversion);
            }
        }

        }      //new

        public void AllowNatTraversal(bool allowed)
        {
            if (allowed)
            {
                m_ClientSocket.SetIPProtectionLevel(IPProtectionLevel.Unrestricted);
            }
            else
            {
                m_ClientSocket.SetIPProtectionLevel(IPProtectionLevel.EdgeRestricted);
            }
        }