300-420 Question 129
Single answerA company wants to segregate traffic for multiple departments by using Virtual Routing and Forwarding (VRF) instances on a single Cisco router. Each department must have its own isolated routing table. Additionally, the IT department's VRF instance must communicate with the HR department's VRF instance to share specific application data. Which design approach allows this communication while maintaining the isolation of other VRFs?
- A
Use route leaking between the IT and HR VRF instances by configuring import and export route targets.
- B
Configure static routes between IT and HR VRFs and enable mutual redistribution.
- C
Collapse all VRFs into a single global routing table to enable communication between departments.
- D
Enable inter-VRF communication by using a Layer 2 VLAN bridging configuration.
Show answer and explanation
Correct answer: A
Explanation
The use of VRFs ensures traffic isolation for different departments. However, when communication is required between specific VRFs, route leaking provides a scalable and secure solution by selectively importing and exporting routes using route targets. This approach maintains the integrity of the VRF design while enabling controlled communication between the IT and HR departments.
- A. Correct.
This is the correct answer. Route leaking allows specific routes to be shared between VRFs by using import and export route targets, ensuring controlled communication while maintaining isolation for other VRFs.
- B. Incorrect.
Static routes and redistribution are not recommended for inter-VRF communication because they complicate route management and may inadvertently compromise VRF isolation.
- C. Incorrect.
Collapsing all VRFs into the global routing table defeats the purpose of using VRFs for traffic segregation, as it eliminates routing isolation entirely.
- D. Incorrect.
Layer 2 VLAN bridging does not support VRF-specific routing and is not a valid method for enabling inter-VRF communication in this scenario.