300-410 Question 73
Single answerA network engineer has configured EIGRP on a router with the variance command to enable unequal-cost load balancing. Which condition must be met for the router to successfully use multiple paths for load balancing?
- A
The feasible successor route's metric must be greater than the successor route's metric.
- B
The feasible successor route's metric must be less than or equal to the successor route's metric multiplied by the variance value.
- C
All paths must have an equal metric to the destination.
- D
The router must only have a single feasible successor.
Show answer and explanation
Correct answer: B
Explanation
EIGRP uses the variance command to enable unequal-cost load balancing. The variance value determines how much larger the feasible successor's metric can be compared to the successor route's metric. If the feasible successor's metric is less than or equal to the successor's metric multiplied by the variance, it is eligible for unequal-cost load balancing. This allows EIGRP to utilize multiple paths to the destination with different costs.
- A. Incorrect.
Incorrect: The feasible successor route's metric cannot be greater than the successor route's metric; this would violate the condition for unequal-cost load balancing.
- B. Correct.
Correct: For unequal-cost load balancing, the feasible successor's metric must be less than or equal to the successor route's metric multiplied by the variance value. This ensures the alternative path is loop-free and can be used for load balancing.
- C. Incorrect.
Incorrect: Equal-cost load balancing requires all paths to have the same metric, but this does not apply to unequal-cost load balancing.
- D. Incorrect.
Incorrect: Multiple feasible successors can exist and be used for load balancing if they meet the variance condition.