350-401 Question 99
Single answerA network engineer is configuring VRFs on a Cisco router to segment traffic for two different departments within the organization: HR and Finance. Each VRF must have its own routing table and should not share routes with the other. After creating the VRFs and assigning interfaces, the engineer notices that communication between devices in the HR network is not working. What is the most likely reason for this issue?
- A
The VRF instances were not associated with the correct interfaces.
- B
The VRF configuration does not include route targets for redistribution.
- C
The devices in the HR network do not have IP addresses configured.
- D
The VRF instances have overlapping route distinguishers (RDs).
Show answer and explanation
Correct answer: A
Explanation
The most likely reason for the issue is that the interfaces were not properly associated with the correct VRFs. Each VRF instance must have its designated interfaces assigned explicitly using the 'ip vrf forwarding' command to route traffic correctly. Without this configuration, devices within a VRF cannot communicate with each other.
- A. Correct.
If the interfaces are not properly assigned to their respective VRFs, traffic will not be routed correctly, resulting in communication failures.
- B. Incorrect.
Route targets are used in MPLS Layer 3 VPNs for importing/exporting routes between VRFs, but they are not required for basic VRF functionality on a single router.
- C. Incorrect.
If the devices in the HR network lacked IP addresses, they would not function at all, but the question specifies that the issue is related to VRF configuration.
- D. Incorrect.
Route distinguishers (RDs) are used to make routes unique across VRFs, but overlapping RDs alone would not cause intra-VRF communication issues.