Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A network security analyst notices that a switch's CPU utilization is spiking and that the switch is flooding unicast frames to all ports. The analyst suspects a MAC address table overflow attack. Which of the following security features should be configured on the switch's access ports to mitigate this type of attack?
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
BPDU guard
BPDU guard protects against STP manipulation, not against MAC flooding.
B
Best answer
Port security
Port security limits the number of MAC addresses per port, directly mitigating MAC flooding attacks.
C
Distractor review
DHCP snooping
DHCP snooping prevents rogue DHCP servers but does not prevent MAC flooding.
D
Distractor review
Dynamic ARP Inspection (DAI)
DAI verifies ARP packets against DHCP snooping bindings and prevents ARP spoofing, not MAC flooding.
Common exam trap
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Technical deep dive
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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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?
Read the scenario before looking for a memorised answer.
What is the correct answer to this question?
The correct answer is: Port security — A MAC flooding attack works by sending frames with many different source MAC addresses to fill the switch's MAC address table (CAM table). Once the table is full, the switch can no longer learn new MAC addresses and begins flooding unknown unicast frames to all ports, which allows an attacker to capture traffic intended for other hosts. Port security is the appropriate feature to mitigate this attack because it limits the number of MAC addresses that can be learned on a single port. Configuring port security with a maximum MAC address count (e.g., 1 or 2) prevents the CAM table from being overwhelmed by a flood of fake MAC addresses on a given port. Option A, BPDU guard, is used to prevent Spanning Tree Protocol attacks by disabling a port if it receives a BPDU that should not appear on an access port. Option C, DHCP snooping, is used to prevent rogue DHCP servers and IP address spoofing. Option D, Dynamic ARP Inspection, is used to prevent ARP spoofing by validating ARP packets against the DHCP snooping bindings table.
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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