* Understanding the Exhibit Setup:
* The network diagram shows an EVPN-VXLAN setup, a common design for modern data centers enabling Layer 2 and Layer 3 services over an IP fabric.
* Leaf1 and Leaf2 are the leaf switches connected to Server1 and Server2, respectively, with each server in a different subnet (172.16.1.0/24 and 172.16.2.0/24).
* Spine1 and Spine2 are part of the IP fabric, interconnecting the leaf switches.
* EVPN-VXLAN Basics:
* EVPN (Ethernet VPN) provides Layer 2 and Layer 3 VPN services using MP-BGP.
* VXLAN (Virtual Extensible LAN) encapsulates Layer 2 frames into Layer 3 packets for transmission across an IP network.
* VTEP (VXLAN Tunnel Endpoint) interfaces on leaf devices handle VXLAN encapsulation and decapsulation.
* Integrated Routing and Bridging (IRB):
* IRB interfaces are required on leaf1 and leaf2 (where the endpoints are directly connected) to route between different subnets (in this case, between 172.16.1.0/24 and 172.16.2.0/24).
* The IRB interfaces provide the necessary L3 gateway functions for inter-subnet communication.
* Traffic Flow Analysis:
* Traffic from Server1 (172.16.1.1) destined for Server2 (172.16.2.1) must traverse from leaf1 to leaf2.
* The traffic will be VXLAN encapsulated on leaf1, sent over the IP fabric, and decapsulated on leaf2.
* Since the communication is between different subnets, the IRB interfaces on leaf1 and leaf2 are crucial for routing the traffic correctly.
* Correct Statements:
* C. An IRB Interface must be configured on leaf1 and leaf2:This is necessary to perform the inter-subnet routing for traffic between Server1 and Server2.
* D. Traffic from server1 to server2 will transit the VXLAN tunnel between leaf1 and leaf2:
This describes the correct VXLAN operation where the traffic is encapsulated by leaf1 and decapsulated by leaf2.
Data Center References:
* In EVPN-VXLAN architectures, the leaf switches often handle both Layer 2 switching and Layer 3 routing via IRB interfaces. This allows for efficient routing within the data center fabric without the need to involve the spine switches for every routing decision.
* The described traffic flow aligns with standard EVPN-VXLAN designs, where direct VXLAN tunnels between leaf switches enable seamless and scalable communication across a data center network.