350-401 Question 400
Single answerA network engineer is troubleshooting an EIGRP-enabled network. Router R1 has multiple paths to reach a destination network, but only one path is installed in the routing table. Upon further inspection, it is observed that one of the backup paths is marked as a feasible successor. What condition must the backup path meet to qualify as a feasible successor?
- A
The reported distance of the backup path must be less than the feasible distance of the current successor.
- B
The feasible distance of the backup path must be less than the reported distance of the current successor.
- C
The advertised distance of the backup path must be greater than the feasible distance of the current successor.
- D
The backup path must have a higher administrative distance than the successor path.
Show answer and explanation
Correct answer: A
Explanation
In EIGRP, a feasible successor is a backup route to a destination that satisfies the loop-free condition. This condition is met if the reported distance of the backup path is less than the feasible distance of the current successor. By ensuring this criterion is met, EIGRP prevents routing loops and ensures a reliable failover mechanism.
- A. Correct.
Correct. To qualify as a feasible successor, the reported distance (RD) of the backup path must be less than the feasible distance (FD) of the current successor. This ensures a loop-free backup path is available.
- B. Incorrect.
Incorrect. The feasible distance (FD) of the backup path is irrelevant in determining its status as a feasible successor. The key factor is the relationship between the reported distance and the feasible distance.
- C. Incorrect.
Incorrect. The advertised distance or reported distance of the backup path should be less (not greater) than the feasible distance of the current successor for it to be considered a feasible successor.
- D. Incorrect.
Incorrect. Administrative distance is not related to the feasible successor selection process in EIGRP; it is used for route preference between different routing protocols.