单项选择题 R1 is internal to area 1, and R2 is internal to area 2. Subnet 10.1.1.0/24 exists in area 2 as a connected subnet off R2. ABR ABR1 connects area 1 to backbone area 0, and ABR2 c onnects area 0 to area 2. Which of the following LSAs must R1 use when calculating R1s best route for 10.1.1.0/24?（）

多项选择题 Routers R1, R2, R3, and R4 connect to the same 10.10.10.0/24 LAN- based subnet. OSPF is fully working in the subnet. Later, R5, whose OSPF priority is higher than the other four routers, joins the subnet. Which of the following are true about the OSPF database exchange process over this subnet at this point?（）

单项选择题 Which of the following OSPF messages contains entire complete LSAs used during the database exchange process?（）