Question 1mediummatching
Full question →Match each switch security or protection feature to its most accurate purpose.
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mediummatchingObjective-mapped
Match each switch security or protection feature to its most accurate purpose.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is mixing up BPDU Guard and Port Security because both involve switch port protection but serve different purposes. Candidates might incorrectly think BPDU Guard limits MAC addresses, but it actually disables ports receiving unexpected BPDUs to protect STP topology. Similarly, confusing DHCP Snooping with Dynamic ARP Inspection is common; DHCP Snooping blocks rogue DHCP servers, while DAI validates ARP packets using DHCP Snooping’s trusted bindings. Misunderstanding these distinctions can lead to incorrect answers about which feature protects against which threat.
Technical deep dive
How to think about this question
Switch security features are critical components in protecting Layer 2 networks from common attacks and misconfigurations. Port Security limits the number of MAC addresses on a switch port, preventing unauthorized devices from connecting or MAC flooding attacks that can disrupt the MAC address table. BPDU Guard protects the Spanning Tree Protocol topology by disabling ports that receive unexpected BPDUs, which are typically only expected on switch-to-switch links, not on edge ports connected to end devices. DHCP Snooping monitors DHCP traffic to build a trusted database of IP-to-MAC bindings and blocks DHCP offers from rogue servers, preventing IP address conflicts and unauthorized network access. Dynamic ARP Inspection uses this trusted binding table to validate ARP packets, ensuring that devices cannot spoof IP-to-MAC mappings and launch man-in-the-middle attacks. These features complement each other by securing different aspects of Layer 2 communication and IP address management. A common exam trap is confusing the purposes of these features because they all enhance switch security but operate differently. For example, BPDU Guard does not limit MAC addresses but protects STP topology, while Port Security limits MAC addresses but does not inspect DHCP or ARP traffic. Understanding the distinct role of each feature helps avoid mistakes in design and troubleshooting scenarios. In practical networks, these features are often deployed together to provide layered security against various threats at the access layer.
KKey Concepts to Remember
- Port security on a Cisco switch restricts the number and identity of MAC addresses allowed on a specific switch port to prevent unauthorized device access.
- BPDU Guard disables a switch port immediately if it receives Bridge Protocol Data Units (BPDUs) on a port configured as an edge port, protecting against potential spanning-tree topology loops.
- DHCP Snooping builds a trusted binding table by monitoring DHCP messages and blocks DHCP responses from untrusted sources to prevent rogue DHCP servers from assigning incorrect IP addresses.
- Dynamic ARP Inspection (DAI) validates ARP packets against the DHCP Snooping binding table to prevent ARP spoofing and man-in-the-middle attacks on a switched network.
- Switch security features like Port Security, BPDU Guard, DHCP Snooping, and Dynamic ARP Inspection each protect different layers and attack vectors in the LAN environment.
- Port Security enforces MAC address limits per port, which helps prevent MAC flooding attacks that can compromise VLAN segmentation and switch forwarding tables.
- BPDU Guard is essential for protecting the Spanning Tree Protocol (STP) topology by disabling ports that should not receive BPDUs, thus preventing accidental or malicious topology changes.
- DHCP Snooping and Dynamic ARP Inspection work together to secure IP address assignment and ARP resolution, ensuring only trusted devices participate in network communication.
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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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 router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
Port security on a Cisco switch restricts the number and identity of MAC addresses allowed on a specific switch port to prevent unauthorized device access.
What exam trap should I watch out for?
Common exam trap: answer the scenario, not the keyword: A frequent exam trap is mixing up BPDU Guard and Port Security because both involve switch port protection but serve different purposes. Candidates might incorrectly think BPDU Guard limits MAC addresses, but it actually disables ports receiving unexpected BPDUs to protect STP topology. Similarly, confusing DHCP Snooping with Dynamic ARP Inspection is common; DHCP Snooping blocks rogue DHCP servers, while DAI validates ARP packets using DHCP Snooping’s trusted bindings. Misunderstanding these distinctions can lead to incorrect answers about which feature protects against which threat.
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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