350-401 Infrastructure Practice Question
A network engineer is configuring a switch stack with two Catalyst 9300 switches. The engineer wants to ensure that if the active switch fails, the standby switch takes over with minimal disruption. Which statement accurately describes the stack MAC address behavior during a failover?
⚠ Common exam trap
The trap here is assuming that the stack MAC address changes immediately upon failover, when in fact it is preserved by default for a persistence period.
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
✓
The stack MAC address remains the same as the original active switch's MAC address unless the stack MAC persistence timer expires.
The stack MAC persistence feature keeps the original active switch's MAC address for a configurable timer (default 4 minutes). During a failover, the standby switch becomes active and continues using that MAC address if the timer has not expired. This minimizes network disruption by avoiding MAC address table updates on neighboring devices.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The stack MAC address is a virtual MAC address generated by the stack protocol and never changes.
Why it's wrong here
Cisco StackWise does not use a virtual MAC address; it uses the MAC address of the original active switch. While the address can persist, it is not a separate virtual address and can change if the persistence timer expires. This option incorrectly describes the stack MAC mechanism.
- ✗
The stack MAC address immediately changes to the new active switch's MAC address upon failover.
Why it's wrong here
If the stack MAC address changed immediately, all neighboring devices would need to relearn MAC addresses, causing temporary traffic disruption. Cisco's default behavior is to preserve the original stack MAC address for a persistence period, so immediate change does not occur unless the timer expires or the feature is disabled.
- ✗
The stack MAC address is always the MAC address of the switch with the highest priority, regardless of failover.
Why it's wrong here
Stack MAC address is not determined by priority; it is inherited from the original active switch and maintained through the persistence timer. Priority affects which switch becomes active, but not the MAC address used by the stack. This option confuses the election process with MAC address persistence.
- ✓
The stack MAC address remains the same as the original active switch's MAC address unless the stack MAC persistence timer expires.
Why this is correct
By default, the stack retains the MAC address of the original active switch for a period defined by the stack MAC persistence timer (default 4 minutes). If the failover occurs and the timer has not expired, the new active switch continues using the same stack MAC address, minimizing disruption to neighboring devices and avoiding MAC address table changes.
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.