Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A network engineer is implementing VLANs for a company. The finance department's workstations are connected to switch ports configured as access ports in VLAN 20. The finance server is located in a different building and is connected to a second switch. The two switches are interconnected via a trunk link. What must be configured on the trunk link to allow finance workstations to communicate with the finance server?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Allow VLAN 20 on the trunk
By default, some trunks may carry only VLAN 1 unless explicitly configured. Adding VLAN 20 to the allowed VLAN list on the trunk ensures that traffic from VLAN 20 can traverse the link.
B
Distractor review
Set the native VLAN to 20 on both switches
The native VLAN is used for untagged traffic on the trunk. Changing it to 20 would not help carry tagged VLAN 20 traffic; it might cause miscommunication if the native VLANs do not match.
C
Distractor review
Configure the trunk port as an access port in VLAN 20
An access port belongs to a single VLAN and does not use tagging. To carry multiple VLANs, a trunk (tagged) port is required.
D
Distractor review
Enable VLAN pruning for all VLANs on the trunk
VLAN pruning (e.g., VTP pruning) removes unnecessary VLAN traffic from trunks but does not actually permit a VLAN to be carried; the VLAN must still be allowed on the trunk.
Common exam trap
Common exam trap: an active trunk can still block the VLAN you need
A trunk being up does not prove every VLAN is crossing it. Check allowed VLAN lists, native VLAN mismatch, VLAN existence and access-port assignment.
Technical deep dive
How to think about this question
VLAN questions usually combine access-port and trunking clues. The key is to identify whether the issue is local to one switchport, caused by the trunk, or caused by the VLAN not existing where it needs to exist.
KKey Concepts to Remember
- Access ports place end devices into a single VLAN.
- Trunk ports carry multiple VLANs between switches.
- Allowed VLAN lists decide which VLANs can cross a trunk.
- Native VLAN mismatch can create confusing symptoms.
TExam Day Tips
- Use show vlan brief to verify access VLANs.
- Use show interfaces trunk to verify trunk state and allowed VLANs.
- Do not treat every same-VLAN issue as a routing problem.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A network engineer needs to connect two switches located 400 meters apart. The cable run includes high electromagnetic interference from nearby machinery. The engineer decides to use fiber optic cabling. Which transceiver type and fiber combination should be used to ensure the link reaches 400 meters while remaining cost-effective?
Question 2
A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?
Question 3
A security engineer is configuring a site-to-site VPN between two branch offices. The requirement is to encrypt all traffic between the two networks using IPsec. Which IPsec mode should be used to encrypt the entire IP packet including the original header?
Question 4
A network administrator is connecting two switches to increase bandwidth and provide redundancy. Which technology should be used to combine multiple physical links into a single logical link?
Question 5
A network administrator is experiencing issues where unauthorized devices are offering IP addresses to clients, causing connectivity problems. Which security feature should be enabled on switches to prevent this?
Question 6
A network administrator is troubleshooting a connectivity issue and suspects the problem is related to the physical cabling. At which layer of the OSI model should the administrator begin their investigation?
FAQ
Questions learners often ask
What does this N10-009 question test?
Access ports place end devices into a single VLAN.
What is the correct answer to this question?
The correct answer is: Allow VLAN 20 on the trunk — Trunk ports carry traffic for multiple VLANs using IEEE 802.1Q tagging. For traffic from VLAN 20 to pass between switches, the trunk must be configured to allow VLAN 20. The native VLAN is used for untagged traffic and is unrelated to allowing specific VLANs. Configuring the trunk as an access port would defeat trunking. VLAN pruning is an optimization that removes unused VLANs, but the basic requirement is to permit the VLAN.
What should I do if I get this N10-009 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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