300-440 Question 45
Single answerA network engineer is troubleshooting EIGRP in a multi-VRF environment on a router configured with EIGRP named mode. The engineer notices that the EIGRP neighbors are not forming in one of the VRFs, while other VRFs are working correctly. What could be the issue?
- A
The EIGRP autonomous system number is incorrectly configured in the problematic VRF.
- B
The router is missing the 'address-family ipv4 unicast' configuration under the EIGRP process for the specific VRF.
- C
The 'redistribute connected' command is missing under the EIGRP process in the global routing table.
- D
The interface associated with the failing VRF is not enabled for EIGRP.
Show answer and explanation
Correct answer: B
Explanation
In EIGRP named mode, each VRF requires its own 'address-family ipv4 unicast' statement under the EIGRP configuration to advertise and establish neighbor relationships for that VRF. Without this configuration, EIGRP will not form neighbors within the specific VRF, even if other VRFs are working correctly. This makes Option 2 the correct answer.
- A. Incorrect.
Incorrect. An incorrect autonomous system number would prevent EIGRP communication globally, not just in a specific VRF. Since other VRFs are operating correctly, this is not the issue.
- B. Correct.
Correct. In EIGRP named mode, the 'address-family ipv4 unicast' statement is required under the EIGRP VRF configuration to enable EIGRP for that VRF. If this configuration is missing, EIGRP neighbors will not form.
- C. Incorrect.
Incorrect. The 'redistribute connected' command is used for redistributing connected routes into EIGRP, but this does not impact neighbor formation.
- D. Incorrect.
Incorrect. An interface not enabled for EIGRP would prevent neighbor formation on that interface, but this option does not account for the absence of specific VRF-related configuration under EIGRP named mode.