Router A learns the same route from two different neighbors; one of the neighbor routers is an OSPF neighbor, and the other is an EIGRP neighbor.
What is the administrative distance of the route that will be installed in the routing table?
The Administrative distance (AD) of EIGRP is 90 while the AD of OSPF is 110 so EIGRP route will be chosen to install into the routing table.
In this scenario, Router A learns the same route from two different neighbors. One neighbor is running OSPF, while the other is running EIGRP. Both neighbors will advertise their route with their own administrative distance (AD) value, and Router A will choose the one with the lower AD value to install into its routing table.
Administrative distance is a metric used by routers to determine the trustworthiness of a routing protocol. It is a numerical value that is assigned to a routing protocol, and it ranges from 0 to 255. The lower the AD value, the more trustworthy the routing protocol is considered to be.
In the Cisco routing table, the AD values of commonly used routing protocols are:
Therefore, the administrative distance of the route that will be installed in the routing table will be determined by the AD value of the routing protocol that advertises the route with the lowest value.
Since EIGRP has an AD value of 90, and OSPF has an AD value of 110, the route learned from EIGRP will be installed in the routing table of Router A. Therefore, the answer is B, 90.