单项选择题
A wireless client cannot connect to an 802.11b/g BSS with a b/g wireless carD.The client section of the access point does not list any active WLAN clients. What is a possible reason for this?（）
A.The incorrect channel is configured on the client. B.The client's IP address is on the wrong subnet. C.The client has an incorrect pre-shared key. D.The SSID is configured incorrectly on the client.
多项选择题 在应用层的各协议中（）协议提供文件传输服务。
单项选择题 Which parameter can be tuned to affect the selection of a static route as a backup. when a dynamic protocol is also being used？（）
单项选择题 某公司申请到一个C类IP地址，需要分配给8个子公司，最好的子网掩码设应为（）。
