OSPF routing makes use of areas. What are the characteristics of these areas? (Choose all that apply.)
A. Hierarchical OSPF networks do not need multiple areas
B. Multiple OSPF areas must connect to area 0
C. Single area OSPF networks must be configured in area 1
D. Areas can be assigned any number from 0 to 63535
E. Area 0 is called the backbone area
F. Each OSPF area need to be configured with a loopback interface
Em chọn B,D,E đúng hong á ?