During OSPF adjacency formation, in which state is a router in when an OSPF hello packet has been sent but bi-directional communication has not been achieved?（）

单项选择题During OSPF adjacency formation, in which state is a router in when it is negotiating to be in charge of the database synchronization process?（）

A.A
B.B
C.C
D.D

单项选择题During OSPF adjacency formation, in which state is a router in when it is negotiating to be in charge of the database synchronization process?（）

A.A
B.B
C.C
D.D

单项选择题During OSPF adjacency formation, in which state is a router when it is sending LSA header information to its neighbor?（）

A.A
B.B
C.C
D.D

单项选择题Which statement is true about the frequency of OSPF LSA transmissions?（）

A.A
B.B
C.C
D.D

单项选择题By default, how often does an ERX Edge Router send an OSPF link-state advertisement in a stable network?（）

A.A
B.B
C.C
D.D