单项选择题
A. A generic Hello
B. Point - to - point Level 1, point - to -point Level 2, LAN Level 1, LAN Level 2
C. Point - to - point Level 1, point - to - point Level 2, LAN
D. Point - to - point, LAN Level 1, LAN Level 2
单项选择题 When learning a new route, if a LSA received is not found in the topological database, what will an internal OSPF router do?（）
单项选择题 One of the most important characteristics of OSPF is Multiple areas. Which statement best describes why this feature is such an important enhancement to earlier routing protocols?（）
单项选择题 Which option is true regarding the synchronization rule ?（）