OSPF DR Selection Configuration Parameters

AC

In an OSPF (Open Shortest Path First) environment, the DR (Designated Router) is a router responsible for sending and receiving OSPF routing information between other routers within the same network segment. The BDR (Backup Designated Router) is a backup router that takes over the DR's responsibilities in case of DR failure.

To determine which router is the DR and BDR in an OSPF environment, the following configuration parameters are used:

1. OSPF Priority: Each router in an OSPF network has a priority value assigned to it, ranging from 0 to 255. By default, the priority value is set to 1. The router with the highest priority value among all the routers in the network segment becomes the DR, and the router with the second-highest priority value becomes the BDR. If two or more routers have the same priority value, the router with the highest RID (Router ID) is selected as the DR.

2. Router ID (RID): The RID is a unique 32-bit identifier assigned to each router running OSPF. The RID can be manually configured or automatically assigned based on the highest IP address on any active interface of the router. If there is a tie in priority value between two or more routers, the router with the highest RID becomes the DR.

Therefore, the correct answers are A (the router with the highest priority) and C (the router with the highest RID) as they are used to determine which router will become the DR in an OSPF environment.