300-420 Question 137
Select 3A company is using OSPF in its enterprise network but recently acquired another organization that uses EIGRP. To allow communication between the networks, the company decides to implement route redistribution. Which of the following considerations should be accounted for to ensure proper operation and to avoid routing issues during OSPF-to-EIGRP redistribution?
- A
Ensure that the seed metric is configured for routes being redistributed into EIGRP.
- B
Avoid redistributing the same routes back into the originating protocol to prevent routing loops.
- C
Use a route-map to filter unnecessary routes during redistribution.
- D
Configure a higher administrative distance for redistributed routes to prioritize native protocol routes.
- E
Enable mutual redistribution without any filters for better route visibility across the network.
Show answer and explanation
Correct answers: A, B, C
Explanation
Redistribution between OSPF and EIGRP requires careful planning to avoid routing issues such as loops and to ensure proper route propagation. Configuring a seed metric is essential for EIGRP to accept redistributed routes. Avoiding loops by not redistributing the same routes back into their originating protocol and filtering routes using route-maps are critical best practices. However, simply adjusting administrative distance or enabling mutual redistribution without any control mechanisms can cause instability and is not recommended.
- A. Correct.
Correct: EIGRP requires a seed metric for redistributed routes; otherwise, the redistributed routes will not be installed into the EIGRP routing table.
- B. Correct.
Correct: Redistributing routes back into the original protocol can cause routing loops, a common issue in multi-protocol environments.
- C. Correct.
Correct: Using a route-map allows control over which routes are redistributed, avoiding unnecessary or problematic routes being introduced into the other protocol.
- D. Incorrect.
Incorrect: Configuring a higher administrative distance for redistributed routes is not a required step during redistribution. Administrative distance is protocol-specific and does not directly address redistribution requirements.
- E. Incorrect.
Incorrect: Enabling mutual redistribution without filters can lead to routing loops and instability, as it does not control the flow of routing information.