350-401 Virtualization Practice Question
A network engineer is configuring a Cisco Nexus 9000 switch with VXLAN EVPN. The engineer wants to ensure that the switch can forward traffic between VLANs that are mapped to the same VXLAN Network Identifier (VNI) but are on different leaf switches. Which component is responsible for mapping the VLAN to the VNI on the ingress leaf switch?
⚠ Common exam trap
Watch out — candidates often confuse the VTEP with the VLAN-to-VNI mapping, as the VTEP uses the mapping but is not the mapping itself.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
VLAN-to-VNI mapping
The VLAN-to-VNI mapping is the component that associates a VLAN with a VNI on the ingress leaf switch. When a frame enters the access port, the switch uses this mapping to encapsulate it in VXLAN with the correct VNI. EVPN route type 2 is for MAC/IP advertisement, the VTEP encapsulates and decapsulates VXLAN traffic, and ingress replication is used for BUM traffic handling. Only the VLAN-to-VNI mapping directly performs the required function.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Ingress replication
Why it's wrong here
Ingress replication is a method for handling broadcast, unknown unicast, and multicast (BUM) traffic in VXLAN. It involves the ingress VTEP replicating BUM frames to all other VTEPs in the VNI. It does not perform VLAN-to-VNI mapping. In EVPN, ingress replication is often replaced by multicast or assisted replication. This mechanism is about flooding, not about mapping VLANs to VNIs. Thus, it is not the correct answer.
- ✓
VLAN-to-VNI mapping
Why this is correct
The VLAN-to-VNI mapping is configured on the ingress leaf switch to associate a VLAN with a VNI. When a frame arrives on an access port in a VLAN, the switch uses this mapping to encapsulate the frame in VXLAN with the corresponding VNI. This allows Layer 2 connectivity to be extended across the VXLAN fabric. The mapping is typically configured under the VLAN configuration or via a VLAN-VNI mapping command. Without this mapping, the switch would not know which VNI to use for encapsulation.
- ✗
VXLAN Tunnel Endpoint (VTEP)
Why it's wrong here
The VXLAN Tunnel Endpoint (VTEP) is responsible for encapsulating and decapsulating VXLAN traffic. It uses the VLAN-to-VNI mapping to determine the VNI, but the VTEP itself is not the mapping. The VTEP is a logical interface (often a loopback) that sources and terminates VXLAN tunnels. While the VTEP uses the mapping, it does not define it. The question asks for the component that maps VLAN to VNI, which is the mapping configuration, not the VTEP.
- ✗
EVPN route type 2
Why it's wrong here
EVPN route type 2 is used to advertise MAC addresses and IP addresses (for ARP suppression) across the EVPN fabric. It helps with MAC address learning and host mobility, but it does not perform the VLAN-to-VNI mapping. The mapping is a local configuration on the ingress leaf switch. Route type 2 is used for control-plane learning, not for data-plane encapsulation decisions. Therefore, it is not responsible for mapping VLAN to VNI on the ingress leaf.
Visual reference
Quick reference
Access Control Model Comparison
| Model | Acronym | Who Controls Access? | Best For |
|---|---|---|---|
| Discretionary Access Control | DAC | Resource owner | Small teams, file shares |
| Mandatory Access Control | MAC | System / security labels | Classified govt / military |
| Role-Based Access Control | RBAC | Administrator (via roles) | Enterprise environments |
| Attribute-Based Access Control | ABAC | Policy engine (user + resource attributes) | Fine-grained, dynamic policies |
| Rule-Based Access Control | RuBAC | System rules / ACLs | Firewall rules, network ACLs |
Go deeper
Related to this question
Learn chapter
Spine-Leaf and Software-Defined Network Architectures
Key term
Spine-Leaf Architecture
Spine-Leaf architecture is a network topology where every lower-layer switch (leaf) connects to every upper-layer switch (spine) to provide predictable and scalable east-west traffic flow.
Key term
VXLAN
VXLAN is a network overlay technology that encapsulates Layer 2 Ethernet frames in UDP packets to extend VLANs across Layer 3 networks.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.