H12-891_V1.0 Exam Dumps : HCIE-Datacom V1.0

Comprehensive and Detailed In-Depth Explanation:

An NVE (Network Virtualization Edge) interface is responsible for connecting physical or virtual devices to a VXLAN network. It functions as the VTEP (VXLAN Tunnel Endpoint) and supports encapsulation and decapsulation of VXLAN packets.

Layer 2 VXLAN gateway (D) is used for intra-subnet communication, but the NVE interface is the actual point where traffic enters the VXLAN network.

Layer 3 VXLAN gateway (A) is used for inter-subnet communication.

VLANIF interface (C) is used for VLAN-based communication, not directly for VXLAN.

Therefore, the NVE interface (B) is the correct answer as it serves as the traffic ingress and egress point for the VXLAN network.

VXLAN Inter-Subnet Routing with Symmetric IRB

VXLAN supports inter-subnet routing using Integrated Routing and Bridging (IRB). In symmetric IRB, both ingress and egress VTEPs perform Layer 3 forwarding to ensure efficient packet forwarding across subnets.

✅ A. Both the ingress VTEP and egress VTEP forward packets based on the Layer 3 forwarding table.

In symmetric IRB, both ingress and egress VTEPs perform Layer 3 lookup and forwarding.

The ingress routes packets before encapsulating them in VXLAN, and the egress performs another Layer 3 lookup to determine final delivery.

✅ D. When VTEPs forward inter-subnet user communication packets, the VNI carried in the VXLAN header is the L3VNI.

L3VNI (Layer 3 VXLAN Network Identifier) is used for inter-subnet routing between VXLAN segments.

When selecting core devices for a WAN in enterprise networks, considerations typically include:

Service volume: Ensures the core device can handle expected traffic.

Physical location: Important for latency, redundancy, and network design.

Node quantity: Affects topology, scalability, and routing complexity.

Device naming conventions, however, are purely administrative and do not affect the functional selection of core devices.

Correct answer: A. Device naming conventions