单项选择题
A.没有设置loopback命令
B.IP地址不正确
C.子网掩码不正确
D.串行链路封装不正确
E.最大传输单元（MTU）设置得太大
F.带宽设置和直连的接口不匹配
单项选择题 You have finished physically installing an access point on the ceiling at your officE.At a minimum, which paramenter must be configured on the access point in order to allow a wireless client to operate on it?（）
单项选择题 At which OSI layer is a logical path created between two host systems（）。
多项选择题 根据下图，网络连接到路由器R2被汇总为一条192.168.176.0/21的路由，并发给R1。哪两个数据包目的地址R1会转发给R2？（）
