多项选择题
A. The command is used to establish a static route.
B. The default administrative distance is used.
C. The command is used to configure the default route.
D. The subnet mask for the source address is 255.255.255.0
E. The command is used to establish a stub network
多项选择题 Which commands are required to properly configure a router to run OSPF and to add network 192.168.16.0/24 to OSPF area 0?（）
多项选择题 On what kinds of networks does OSPF elect a backup designated router?（）
多项选择题 Which of the following are true statements regarding the characteristics of OSPF areas? Select all that apply.（）