Referring to the exhibit, the image shows a simplified diagram of an IP fabric network connecting two servers, labeled as Server A and Server B. The IP fabric is a network architecture that uses a Clos topology to provide high bandwidth, low latency, and scalability for data center networks. The IP fabric consists of spine and leaf devices that use BGP as the routing protocol and VXLAN as the overlay technology1.
A broadcast domain is a logical portion of a network where any device can directly transmit broadcast frames to other devices at the data link layer (OSI Layer 2). A broadcast frame is a frame that has a destination MAC address of all ones (FF:FF:FF:FF:FF:FF), which means that it is intended for all devices in the same broadcast domain. A broadcast domain is usually bounded by a router, which does not forward broadcast frames to other networks2.
In the exhibit, there are two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The first broadcast domain is the one that contains Server A and the leaf device that it is connected to. The second broadcast domain is the one that contains Server B and the leaf device that it is connected to. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network. Therefore, the statement C is correct in this scenario.
The following three statements are incorrect in this scenario:
A. 1. This is not true, because there are not one, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.
B. 4. This is not true, because there are not four, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The spine devices and the leaf devices that are not connected to the servers are not part of the broadcast domains, because they use IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.
D. 3. This is not true, because there are not three, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.
