350-401 Virtualization Practice Question
A network engineer is designing a new data center leaf-spine fabric using Cisco Nexus 9000 switches. The design requires that the fabric automatically discover the IP addresses of remote VTEPs participating in a VXLAN EVPN deployment. Which control-plane protocol should be enabled on the leaf switches to provide this dynamic VTEP discovery?
⚠ Common exam trap
It's easy for candidates to confuse the underlay routing protocol (such as OSPF or IS-IS) with the overlay control plane that actually carries VTEP reachability and MAC/IP bindings.
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
✓
Multiprotocol BGP with EVPN address family
VXLAN EVPN uses MP-BGP with the EVPN address family as the overlay control plane. It advertises Type-2 (MAC/IP) and Type-3 (IMET) routes, allowing leaf switches to learn remote VTEP IP addresses automatically. This eliminates the need for static VTEP configuration and supports efficient multi-tenancy and mobility.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
OSPFv3 in the underlay network
Why it's wrong here
OSPFv3 is a routing protocol for the underlay, exchanging prefix reachability between leaf and spine switches. It does not carry VXLAN EVPN route types nor VTEP IP addresses. While the underlay must be routable, OSPFv3 alone cannot provide dynamic VTEP discovery for the overlay.
- ✗
Protocol Independent Multicast (PIM) sparse mode
Why it's wrong here
PIM sparse mode is used for multicast replication in flood-and-learn VXLAN, not for EVPN control-plane VTEP discovery. PIM builds multicast distribution trees but does not advertise VTEP IP addresses or MAC/IP bindings. It is not the control plane mechanism for EVPN-based fabrics.
- ✗
Cisco Fabric Services (CFS) over the management network
Why it's wrong here
CFS is used for configuration synchronization and distribution within Cisco Nexus or ACI environments, not for VXLAN EVPN VTEP discovery. It does not advertise EVPN routes or VTEP IPs. Relying on CFS would not enable dynamic VTEP learning in a standards-based VXLAN EVPN fabric.
- ✓
Multiprotocol BGP with EVPN address family
Why this is correct
MP-BGP with the EVPN address family is the control plane for VXLAN EVPN. It advertises Type-2 and Type-3 routes that carry VTEP IP addresses, enabling automatic discovery of remote VTEPs. Without it, VTEPs must be statically configured, losing the dynamic fabric benefits of EVPN.
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
SDN Controllers and Cisco ACI
Key term
Cisco Virtual Topology System
Cisco Virtual Topology System is a software-defined networking solution that creates and manages virtual network overlays across physical and virtual infrastructure for enterprise networks.
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.