350-401 Question 401
Single answerA network engineer is troubleshooting EIGRP routing in a network and notices that a specific route is not being installed in the routing table. The engineer checks the topology table and observes the following details for the route to 192.168.1.0/24:
- Reported Distance (RD): 20000
- Feasible Distance (FD): 25000
- Feasibility Condition (FC): Satisfied
- Successor: 10.1.1.2
- Feasible Successor: 10.1.1.3
Which of the following is the most likely reason why the route to 192.168.1.0/24 is not being installed in the routing table?
- A
The Successor's route is in a Stuck in Active (SIA) state.
- B
The Feasibility Condition (FC) is not satisfied.
- C
The route's Feasible Distance (FD) is higher than the current best route FD.
- D
The route is in the topology table but not selected as the best path due to a lower administrative distance.
Show answer and explanation
Correct answer: A
Explanation
EIGRP routes can enter a Stuck in Active (SIA) state when EIGRP queries fail to receive a response from neighbors. In this case, the Successor route (10.1.1.2) is in an SIA state, preventing the route to 192.168.1.0/24 from being installed in the routing table, even though the Feasibility Condition is satisfied and a Feasible Successor exists.
- A. Correct.
A route will not be installed in the routing table if the Successor's route is in an SIA state because it indicates the route is in an unresolved or incomplete state.
- B. Incorrect.
This is incorrect because the Feasibility Condition (FC) is explicitly stated as satisfied in the question.
- C. Incorrect.
This is incorrect because the Feasible Distance (FD) is not compared with other routes in this context; the FD of 25000 is valid for route selection.
- D. Incorrect.
Administrative distance is not the factor discussed in this scenario, as the route is explicitly in the topology table but cannot be installed due to the SIA state.