CCNP Virtualization Practice Question
A network engineer is configuring a Cisco Nexus 9000 switch as a VTEP in a VXLAN EVPN fabric. The engineer wants to ensure that the switch uses the loopback0 interface as the source for VXLAN tunnels and that it can dynamically learn remote VTEPs via BGP EVPN. Which command set is required under the NVE interface?
⚠ Common exam trap
The trap here is forgetting the host-reachability protocol bgp command, which is often overlooked when focusing only on the source-interface configuration.
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
✓
interface nve1; source-interface loopback0; host-reachability protocol bgp
For a Cisco Nexus 9000 VTEP in an EVPN fabric, the NVE interface must be configured with source-interface loopback0 to set the tunnel source IP and host-reachability protocol bgp to enable dynamic learning of remote VTEPs and MAC addresses via BGP EVPN. Other commands like no shutdown are necessary but insufficient, and static peer-ip or IP address under NVE is incorrect.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
interface nve1; source-interface loopback0; vni 10000; ip address 10.0.0.1/32
Why it's wrong here
The NVE interface does not require an IP address; the source-interface command specifies the loopback whose IP is used. Adding an IP address under NVE is invalid and unnecessary. Also, while VNI configuration is needed, it is typically done under the NVE interface with member vni, not as shown. The critical host-reachability protocol bgp is missing.
- ✗
interface nve1; source-interface loopback0; no shutdown
Why it's wrong here
While source-interface loopback0 is correct, simply bringing up the NVE interface with no shutdown does not enable BGP EVPN control plane learning. The NVE would still rely on flood-and-learn for remote MACs, which is not desired in an EVPN fabric. The host-reachability protocol bgp command is missing, so dynamic EVPN learning would not occur.
- ✗
interface nve1; source-interface loopback0; peer-ip 10.0.0.2
Why it's wrong here
The peer-ip command is used in static VXLAN configurations to specify remote VTEPs manually. In an EVPN fabric, remote VTEPs are learned dynamically via BGP EVPN, so peer-ip is not used. The host-reachability protocol bgp command is required instead. Using peer-ip would create a static tunnel, defeating the purpose of EVPN.
- ✓
interface nve1; source-interface loopback0; host-reachability protocol bgp
Why this is correct
Under the NVE interface, source-interface loopback0 sets the VTEP IP address, and host-reachability protocol bgp enables BGP EVPN for remote VTEP and MAC learning. This combination is essential for a functioning VTEP in an EVPN fabric. Without the source-interface, the NVE would not know which IP to use for tunnels, and without host-reachability, it would rely on data-plane learning.
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 |
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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.