Xác thực dựa trên Web để lại máy chủ Exchange của bạn mở các cuộc tấn công mật khẩu bạo lực từ Internet. Sử dụng các công cụ dễ dàng có được, người không được phép có thể chạy đăng nhập tự động chống lại mạng của bạn có thể được truy cập vào tài khoản thông qua việc sử dụng các mật khẩu yếu hoặc mặc định công ty. | Chapter 12 Secure Wireless Access with Virtual Private Networking 225 Considering Lager 2 Tunneling Protocol Microsoft s implementations of Layer 2 Tunneling Protocol L2TP and Internet Protocol Security IPSec are available on the Windows 2000 and 2003 platforms and are designed to provide the highest possible security. Unfortunately as a result of this increased level of security these VPN solutions require the deployment of a Public Key Infrastructure along with Pentium-class processors. A Microsoft L2TP IPSec VPN Client is available that allows computers running Windows 98 Windows Me and even legacy Windows NT Workstation to use L2TP connections with IPSec. I doubt very much if anyone still uses these clients they are so old. However should you be one of those I have three words for you Get new clients. Easy eh Really neither of the Windows 98 Me clients offers security and NT is no longer supported. You should be moving up to XP by now for the added support security and total cost of operation benefits available. L2TP allows IP IPX or NetBEUI traffic to be encrypted as we mentioned earlier and then sent over any of the various network types such as IP the most obvious for us Frame Relay or ATM. L2TP uses IPSec to start encryption earlier than the PPTP connection providing greater security. It also allows for stronger encryption algorithms to protect the data. Finally IPSec provides data integrity which proves that the data isn t modified in transit replay protection which prevents anyone from resending a captured packet stream and data confidentiality by using encryption. PPTP only provides data confidentiality. As we mention earlier this is a more robust secure method but needs more work to implement it. Perhaps in another book. Using Windows iPSec IPSec is an industry standard for encryption that Microsoft includes in its newer Windows 2000 XP and 2003 operating systems. It is reasonably easy to set up between Windows machines and offers excellent .
