Which statement best describes an Open Shortest Path First (OSPF) area border router (ABR)? A. It maintains a link-state database for only a single area’s topology.
B. It maintains a link-state database for each area to which it is connected.
C. It floods summary link advertisements (SLA) to only its assigned area, dropping all other SLAs.
D. It connects to routers located in other autonomous systems (AS).
The correct answer is B. It maintains a link-state database for each area to which it is connected.
### Explanation:
An Open Shortest Path First (OSPF) Area Border Router (ABR) serves as a boundary between OSPF areas. It is responsible for maintaining a link-state database for all areas it connects to, allowing it to summarize and share routing information between different OSPF areas. This is crucial for efficient routing and ensuring that each area can communicate effectively without becoming overwhelmed by the full topology of the network.
If you have any more questions or need further assistance, don’t hesitate to ask!