300-420 Question 116
Select 2An enterprise network is using two equal-cost paths between its headquarters and a branch office to ensure redundancy and load sharing. The network administrator notices that traffic is not being distributed equally across both paths. Which of the following adjustments should be made to ensure proper load sharing in this scenario?
- A
Enable Equal-Cost Multi-Path (ECMP) routing on the routing protocol used.
- B
Modify the routing protocol to use metrics that account for bandwidth differences.
- C
Adjust the load balancing algorithm on the device to use per-packet load sharing instead of per-flow.
- D
Enable policy-based routing (PBR) to manually distribute traffic across both paths.
- E
Increase the path cost of one of the routes to prioritize the other path.
Show answer and explanation
Correct answers: A, C
Explanation
To ensure proper load sharing in a scenario with equal-cost paths, Equal-Cost Multi-Path (ECMP) routing must be enabled, as it allows the routing protocol to leverage multiple equal-cost routes. Additionally, adjusting the load balancing algorithm to use per-packet load sharing ensures that traffic is evenly distributed across the paths. Other options like modifying routing metrics, using policy-based routing, or increasing path cost are either irrelevant or counterproductive in this scenario.
- A. Correct.
Enabling Equal-Cost Multi-Path (ECMP) routing allows the routing protocol to distribute traffic across multiple equal-cost paths for load sharing, which directly addresses the issue.
- B. Incorrect.
Modifying the routing protocol to use metrics that account for bandwidth differences is not relevant to this scenario, as the issue described involves equal-cost paths, not unequal paths.
- C. Correct.
Adjusting the load balancing algorithm to use per-packet load sharing can help ensure traffic is more evenly distributed across equal-cost paths, as per-flow load sharing might result in uneven traffic distribution.
- D. Incorrect.
Policy-based routing (PBR) is typically used for specific traffic engineering requirements, not for general load sharing across equal-cost paths. This would complicate the configuration unnecessarily.
- E. Incorrect.
Increasing the path cost of one of the routes would remove the equal-cost status, which would defeat the purpose of using load sharing.