You are deploying an EVPN-VXLAN overlay. You must ensure that Layer 3 routing happens on the spine devices. In this scenario, which deployment architecture should you use?
Correct Answer: B
* Understanding EVPN-VXLAN Architectures: * EVPN-VXLAN overlays allow for scalable Layer 2 and Layer 3 services in modern data centers. * CRB (Centralized Routing and Bridging):In this architecture, the Layer 3 routing is centralized on spine devices, while the leaf devices focus on Layer 2 switching and VXLAN tunneling. This setup is optimal when the goal is to centralize routing for ease of management and to avoid complex routing at the leaf level. * ERB (Edge Routing and Bridging):This architecture places routing functions on the leaf devices, making it a distributed model where each leaf handles routing for its connected hosts. * Architecture Choice for Spine Routing: * Given the requirement to ensure Layer 3 routing happens on the spine devices, theCRB (Centralized Routing and Bridging)architecture is the correct choice. This configuration offloads routing tasks to the spine, centralizing control and potentially simplifying the overall design. * Explanation: * With CRB, the spine devices perform all routing between VXLAN segments. Leaf switches handle local switching and VXLAN encapsulation, but routing decisions are centralized at the spine level. * This model is particularly advantageous in scenarios where centralized management and routing control are desired, reducing the complexity and configuration burden on the leaf switches. Data Center References: * The CRB architecture is commonly used in data centers where centralized control and simplified management are key design considerations. It allows the spines to act as the primary routing engines, ensuring that routing is handled in a consistent and scalable manner across the fabric.
Question 22
You are asked to build redundant gateways in your EVPN-VXLAN environment, but you must conserve address space because these gateways must span across seven PES. What should you implement on the PEs lo satisfy these requirements?
Correct Answer: C
* Redundant Gateways in EVPN-VXLAN: * In an EVPN-VXLAN environment, providing redundant gateway functionality typically involves the use of Anycast Gateway. This allows multiple PEs (Provider Edge devices) to use the same IP address and MAC address for the gateway, enabling seamless failover and redundancy without IP conflicts. * Conserving Address Space: * Using the same IP address across multiple PEs conserves address space because only one IP address is needed for the gateway function, regardless of the number of PEs. The shared MAC address ensures that ARP resolution and forwarding behavior are consistent across all the PEs. Conclusion: * Option C:Correct-Using IRB interfaces with the same IP and MAC address across all PEs satisfies the need for redundancy while conserving address space. OptionsA, B,andDintroduce unnecessary complexity or do not fully utilize the efficient Anycast Gateway approach, which is best practice for conserving IP space and providing redundancy.
