单项选择题
A.Physical
B.Session
C.Application
D.Data-Link
E.Network
单项选择题 The following command is issued on a Cisco Router： Router（configuration）#logging console warnings Which alerts will be seen on the console？（）
单项选择题 Youhave2NTPserversinyournetwork-10.1.1.1and10.1.1.2.YouwanttoconfigurationureaCiscoroutertouse10.1.1.2asitsNTPserverbeforefallingbackto10.1.1.1.Whichcommandswillyouusetoconfigurationuretherouter？（）
单项选择题 What level of logging is enabled on a Router where the following logs are seen？（）