Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
A company wants to prevent unauthorized devices from connecting to the corporate network. The policy requires that only specific MAC addresses are permitted on switch ports. Which security feature should be implemented on the switches?
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
Distractor review
802.1X authentication
802.1X uses usernames/passwords or certificates for authentication, not MAC addresses. While it can be integrated with MAC authentication bypass, the question specifically asks for MAC-based restriction.
B
Best answer
MAC filtering / Port security
Port security (MAC filtering) allows an administrator to define a list of allowed MAC addresses on a switch port. Any device with a MAC not on the list is blocked from sending traffic.
C
Distractor review
VLAN hopping prevention
VLAN hopping prevention techniques (e.g., disabling DTP, setting native VLAN to unused) protect against attacks that attempt to access other VLANs, not against unauthorized device connections.
D
Distractor review
DHCP snooping
DHCP snooping prevents rogue DHCP servers and maintains a binding table of IP-MAC addresses. It does not directly restrict which MAC addresses can connect to a port.
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: MAC filtering / Port security — MAC filtering (also called port security) allows an administrator to specify which MAC addresses are allowed to connect to a switch port. 802.1X is a more robust authentication framework that uses credentials, but the scenario explicitly mentions MAC addresses, making port security the direct solution. VLAN hopping prevention and DHCP snooping address different threats.
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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