N10-009 Network Implementation Practice Question
A network administrator is creating a new VLAN 50 on a switch. After creating the VLAN, the administrator notices that the switch does not send VLAN information to other switches in the network. Which of the following is the most likely reason?
⚠ Common exam trap
The N10-009 exam often tests the misconception that a trunk misconfiguration (like not allowing the VLAN on the trunk) is the cause of VTP propagation failure, when in fact VTP transparent mode completely disables advertisement generation regardless of trunk settings.
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
✓
VTP mode is set to transparent.
When VTP mode is set to transparent, the switch does not originate or forward VTP advertisements, so VLAN changes made on it are not propagated to other switches. This explains why VLAN 50 was created locally but not shared with the rest of the network.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
VTP mode is set to transparent.
Why this is correct
A switch configured in VTP transparent mode will not synchronize its VLAN database with other switches in the VTP domain, nor will it advertise its own local VLAN changes. While it forwards VTP advertisements from other switches, it does not participate in the VTP propagation process by originating or learning VLANs. Therefore, creating VLAN 50 on a transparent mode switch means this VLAN will remain local to that switch and will not be learned by other VTP-participating switches.
- ✗
The trunk link is not configured.
Why it's wrong here
VTP advertisements rely on properly configured trunk links to propagate VLAN information between switches within a VTP domain. If no trunk link were established, VTP messages could not be exchanged, and VLAN changes would indeed fail to propagate. However, the question implies a scenario where a new VLAN is created but not propagated, suggesting that a trunk link likely exists, but another configuration issue, such as the VTP mode, is preventing the propagation.
When this WOULD be correct
A network administrator creates a new VLAN on a switch and notices that devices in that VLAN cannot communicate with devices on other switches. In this scenario, the trunk link not being configured would be the most likely reason because inter-switch VLAN traffic requires a trunk.
- ✗
The VLAN is not allowed on the trunk.
Why it's wrong here
If VLAN 50 is explicitly pruned or not allowed on a trunk link, it means data frames tagged with VLAN 50 cannot traverse that specific trunk. However, VTP advertisements, which carry VLAN database updates, are control plane messages sent untagged or on the native VLAN across trunk links. These advertisements would still propagate, assuming the switch is in VTP server or client mode, regardless of whether specific data VLANs are permitted on the trunk.
- ✗
STP is blocking the VLAN.
Why it's wrong here
Spanning Tree Protocol (STP) operates to prevent network loops by blocking redundant paths at the port level, ensuring a loop-free logical topology. STP's blocking state primarily affects the forwarding of data frames and certain control plane traffic on specific ports. It does not, however, prevent VTP advertisements from being sent or received across active trunk links, as VTP operates at a different layer and mechanism to propagate VLAN database changes.
When this WOULD be correct
In a scenario where a switch cannot communicate with other switches on a specific VLAN (e.g., hosts cannot ping across the network), and the administrator has verified trunk and VLAN configurations, STP blocking that VLAN due to a loop or port role (e.g., alternate port) would be the likely cause.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓VTP mode is set to transparent.Correct answer▾
Why this is correct
A switch configured in VTP transparent mode will not synchronize its VLAN database with other switches in the VTP domain, nor will it advertise its own local VLAN changes. While it forwards VTP advertisements from other switches, it does not participate in the VTP propagation process by originating or learning VLANs. Therefore, creating VLAN 50 on a transparent mode switch means this VLAN will remain local to that switch and will not be learned by other VTP-participating switches.
✗The trunk link is not configured.Wrong answer — click to see why▾
Why this is wrong here
The trunk link not being configured would prevent any VLAN traffic from passing between switches, but the question states that VLAN 50 was created and only VLAN information is not being sent. VTP (VLAN Trunking Protocol) is responsible for sharing VLAN information, and its mode (transparent) is the direct cause here.
★ When this WOULD be the correct answer
A network administrator creates a new VLAN on a switch and notices that devices in that VLAN cannot communicate with devices on other switches. In this scenario, the trunk link not being configured would be the most likely reason because inter-switch VLAN traffic requires a trunk.
Why candidates choose this
Candidates may confuse the need for a trunk to carry VLAN traffic with the need for VTP to propagate VLAN information, assuming that if VLAN info isn't shared, the trunk must be missing.
✗STP is blocking the VLAN.Wrong answer — click to see why▾
Why this is wrong here
STP blocking a VLAN would prevent data traffic from passing, but it does not affect the switch's ability to send VLAN information via VTP. The issue here is that VLAN information is not being propagated, which points to VTP configuration, not STP.
★ When this WOULD be the correct answer
In a scenario where a switch cannot communicate with other switches on a specific VLAN (e.g., hosts cannot ping across the network), and the administrator has verified trunk and VLAN configurations, STP blocking that VLAN due to a loop or port role (e.g., alternate port) would be the likely cause.
Why candidates choose this
Candidates may confuse STP's role in blocking redundant paths with the propagation of VLAN information, or they may think that STP can block control plane traffic like VTP updates.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
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Related to this question
Learn chapter
Physical Network Infrastructure
Key term
VTP
VTP (VLAN Trunk Protocol) is a Cisco proprietary protocol that manages the addition, deletion, and renaming of VLANs across a switched network.
Key term
VLAN
A VLAN logically segments a physical network into isolated broadcast domains without requiring separate physical switches.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This N10-009 practice question is part of Courseiva's free CompTIA 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 N10-009 exam.