Question 1mediummulti select
Full question →mediummulti selectObjective-mapped
Exhibit
Desired behavior: - one known endpoint per port - violation causes interface shutdown
A switch should learn one MAC address on an access port and shut the port down if a second unauthorized device appears. Which two port-security settings support that requirement?
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
switchport port-security maximum 1
This limits the number of learned secure MAC addresses to one.
B
Best answer
switchport port-security violation shutdown
This forces the interface into the shutdown/err-disabled state on violation.
C
Distractor review
switchport protected
Protected ports affect forwarding behavior, not MAC learning limits.
D
Distractor review
switchport nonegotiate
This disables DTP negotiation and is unrelated to port-security violations.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is confusing the port-security violation modes. Many candidates mistakenly believe that 'restrict' or 'protect' modes will shut down the port when a violation occurs. However, 'restrict' only drops packets from unauthorized MAC addresses and logs the violation, while 'protect' silently drops unauthorized traffic without logging. Only the 'shutdown' mode places the port into an error-disabled state, effectively shutting it down. Misunderstanding this can lead to incorrect answers when the question specifically requires the port to shut down upon a second unauthorized device detection.
Technical deep dive
How to think about this question
Port security is a Cisco switch feature that restricts input to an interface by limiting and identifying MAC addresses of the stations allowed to access the port. It enhances network security by preventing unauthorized devices from connecting to the network through that port. When enabled, the switch learns MAC addresses dynamically or can be configured with static addresses, and it enforces limits on how many addresses can be learned or allowed. The command 'switchport port-security maximum 1' configures the port to learn and allow only one MAC address, which is ideal for access ports connected to a single device. The 'switchport port-security violation shutdown' command specifies that if a violation occurs—such as a second unauthorized MAC address appearing—the port will be put into an error-disabled state, effectively shutting it down to prevent unauthorized access. This combination ensures strict control over device connections on access ports. A common exam trap is confusing port-security violation modes. Besides 'shutdown', other violation modes like 'restrict' or 'protect' exist, which do not disable the port but only limit traffic or log violations. Candidates might incorrectly select these modes, thinking they enforce strict security. Understanding that 'shutdown' is the only mode that disables the port on violation is critical for correctly answering questions about strict port-security enforcement in CCNA exams.
KKey Concepts to Remember
- Port security on Cisco switches limits the number of MAC addresses learned on a port to control device access and enhance network security.
- The 'switchport port-security maximum 1' command restricts the port to learn and allow only one MAC address, suitable for access ports with a single device.
- The 'switchport port-security violation shutdown' command causes the port to enter an error-disabled state when a security violation occurs, effectively shutting down the port.
- When a second unauthorized MAC address is detected on a port with port security enabled, the configured violation action determines how the switch responds to the breach.
- Port-security violation modes include 'shutdown', 'restrict', and 'protect', but only 'shutdown' disables the port, which is essential for strict security enforcement.
- Access ports are typically configured with port security to prevent unauthorized devices from connecting and potentially compromising the network.
- Switches learn MAC addresses dynamically on ports unless static secure MAC addresses are configured, and port security enforces limits on these learned addresses.
- The error-disabled state caused by a port-security violation requires manual intervention or configured recovery to re-enable the port.
TExam Day Tips
- 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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Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
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Question 3
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FAQ
Questions learners often ask
What does this 200-301 question test?
Port security on Cisco switches limits the number of MAC addresses learned on a port to control device access and enhance network security.
What is the correct answer to this question?
The correct answer is: switchport port-security maximum 1 — Port security enforces how many MAC addresses may be learned on a port and what happens when a violation occurs. Maximum 1 plus violation shutdown matches the requirement.
What should I do if I get this 200-301 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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