, như thể hiện trong hình 5-9. Windows sẽ tự động điều chỉnh giá trị này, nhưng nó phải luôn luôn được ở dưới giá trị được thể hiện trong Bảng 5-3 cho các thiết lập cấu hình. Để tải về Network Monitor, hãy truy cập , và tìm kiếm các hướng dẫn chi tiết | 310 Windows Server 2008 Networking and Network Access Protection NAP Network-layer roaming occurs when a wireless client connects to a different wireless AP for the same wireless network within the same subnet. For network-layer roaming the wireless client renews its current DHCP configuration. When a wireless client connects to a different wireless AP for the same wireless network that is on a different subnet the wireless client gets a new DHCP configuration that is relevant to that new subnet. When you cross a subnet boundary applications that cannot handle a change of IPv4 or IPv6 address such as some e-mail applications might fail. When creating an IPv4 subnet prefix for your wireless clients consider that you need at least one IPv4 address for the following Each wireless AP s LAN interface that is connected to the wireless subnet. Each router interface that is connected to the wireless subnet. Any other TCP IP-capable host or device that is attached to the wireless subnet. Each wireless client that can connect to the wireless network. If you underestimate this number Windows wireless clients that connect after all of the available IPv4 addresses have been assigned through DHCP to connected wireless clients will automatically configure an IP address with no default gateway using Automatic Private IP Addressing APIPA . This configuration does not allow connectivity to the intranet. Wireless clients with APIPA configurations will periodically attempt to obtain a DHCP configuration. Because each IPv6 subnet can support a very large number of hosts you do not need to determine the number of IPv6 addresses needed for the IPv6 subnet prefix. DHCP Design for Wireless Clients With different subnets for wired and wireless clients you must configure separate DHCP scopes. Because wireless clients can easily roam from one wireless subnet to another you should configure the lease for the DHCP scopes to have a shorter duration for wireless subnets than for wired subnets. .
