300-420 Question 128
Single answerA company is designing a multi-tenant network for its data center using Virtual Routing and Forwarding (VRF). The requirement is to ensure complete traffic isolation between tenants while minimizing the number of physical interfaces required on the routers. Which design approach best meets these requirements?
- A
Use VRFs with separate physical interfaces for each tenant's traffic.
- B
Implement VRFs with a shared physical interface and use sub-interfaces with 802.1Q VLAN tagging for tenant traffic segregation.
- C
Assign each tenant a unique IP address range without using VRFs.
- D
Use multiple routers, one dedicated to each tenant, to ensure traffic isolation.
Show answer and explanation
Correct answer: B
Explanation
The correct design approach is to use VRFs with a shared physical interface and sub-interfaces employing 802.1Q VLAN tagging. This method enables complete traffic isolation by mapping each tenant's traffic to a separate VRF while minimizing the number of physical interfaces required. The use of sub-interfaces ensures efficient resource utilization and compliance with the given requirements.
- A. Incorrect.
Using separate physical interfaces for each tenant's traffic ensures isolation but increases hardware requirements, which contradicts the requirement to minimize physical interfaces.
- B. Correct.
Using VRFs with a shared physical interface and sub-interfaces with 802.1Q VLAN tagging allows for traffic isolation at Layer 3 while minimizing the need for additional interfaces, making it the most efficient solution.
- C. Incorrect.
Assigning unique IP address ranges without VRFs does not guarantee traffic isolation, as traffic from different tenants could still traverse the same routing table.
- D. Incorrect.
Using multiple routers for traffic isolation would ensure tenant segregation but significantly increases hardware costs and does not align with the requirement to minimize physical interfaces.