97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区 狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項選擇題

A network administrator provides an IP address of 128.135.0.142 and a subnet mask of 255.0.0.0.  Once a ping is attempted, it fails.  Which of the following options is the most probable cause of the failed ping?()

A.0 is not valid in an IP address
B.128 is a reserved network
C.The subnet mask should be 255.255.0.0. since it is a class B
D.A network problem has occurred since IP and subnet are valid

微信掃碼免費搜題