Fabric Intermediate Nodes

D.

In an SD-Access architecture, the fabric intermediate nodes play a crucial role in the overall network design. These nodes are responsible for forwarding traffic between the access and border nodes in the SD-Access fabric.

Out of the options provided, the correct function that fabric intermediate nodes are responsible for is option D: transporting IP packets between edge nodes and border nodes.

The edge nodes are responsible for connecting end devices to the fabric, while the border nodes provide connectivity to external networks. The fabric intermediate nodes, as the name suggests, are situated in between these edge and border nodes and facilitate traffic forwarding between them.

When a device connected to an edge node sends traffic to a device connected to a border node, the traffic must traverse the fabric intermediate nodes. These nodes use various technologies such as VXLAN, IP routing, and MPLS to transport the IP packets between the edge and border nodes.

Option A is incorrect as the responsibility of mapping EIDs (Endpoint IDs) to RLOCs (Routing Locators) is performed by the Control Plane nodes in the fabric, such as the border nodes, control plane nodes, and border relay nodes.

Option B is incorrect as encapsulating user traffic in a VXLAN header including the SGT (Security Group Tag) is the responsibility of the edge nodes, not the fabric intermediate nodes.

Option C is also incorrect as registering new endpoints in the HTDB (Host Tracking Database) is performed by the Control Plane nodes in the fabric, such as the border nodes, control plane nodes, and border relay nodes.

Therefore, the correct function that fabric intermediate nodes are responsible for in an SD-Access Architecture is transporting IP packets between edge nodes and border nodes.