JNCIS-ENT Layer 2 Switching And VLANs Practice Question
An administrator notices that MAC address flapping is occurring between two ports on an EX Series switch due to an unauthorized bridge loop. Which Junos feature can be enabled to automatically detect and action on MAC address movement anomalies?
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
✓
set ethernet-switching-options secure-access-port interface ge-0/0/0 mac-move-limit action shutdown
MAC move detection and port restriction (mac-move-limit) can detect rapid MAC address flapping and disable the offending interface.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
set interfaces ge-0/0/0 family ethernet-switching loop-protect
Why it's wrong here
Loop protection on interfaces uses bridge PDUs or spanning tree, not MAC move tracking.
- ✗
set ethernet-switching-options mac-move-limit action errdisable
Why it's wrong here
The exact Junos keyword for action on MAC move limit involves setting actions like drop or shutdown.
- ✗
set protocols rstp bpdu-protection-recovery
Why it's wrong here
BPDU protection handles spanning tree BPDUs, not MAC move flapping directly.
- ✓
set ethernet-switching-options secure-access-port interface ge-0/0/0 mac-move-limit action shutdown
Why this is correct
Correct. Secure access port options include mac-move-limit settings to take action against MAC address flapping.
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 |
About these practice questions
One of 506 original JNCIS-ENT practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Juniper Networks exam blueprint
This JNCIS-ENT practice question is part of Courseiva's free Juniper Networks 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 JNCIS-ENT exam.