Question 1mediummatching
Full question →Match each switch protection feature to its most accurate purpose.
Answer choices are not available in this preview. Open the full question page for the complete review.
mediummatchingObjective-mapped
Match each switch protection feature to its most accurate purpose.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is confusing the purposes of Layer 2 protection features such as Port Security, BPDU Guard, DHCP Snooping, and Dynamic ARP Inspection. Candidates might assume these features overlap or serve the same function, but each addresses a distinct Layer 2 security risk. For example, mistaking BPDU Guard as a MAC address control or DHCP Snooping as ARP validation leads to incorrect answers. The exam often tests your ability to differentiate these features precisely, so mixing their purposes can cause errors.
Technical deep dive
How to think about this question
Layer 2 protection features in Cisco switches are designed to secure the network at the data link layer by preventing common attacks and misconfigurations. Port Security restricts the number of MAC addresses learned on a switch port, preventing unauthorized devices from connecting. BPDU Guard protects the Spanning Tree Protocol (STP) topology by disabling ports that receive unexpected Bridge Protocol Data Units (BPDUs), which are typically sent by switches, not end devices. DHCP Snooping filters DHCP messages to block rogue DHCP servers and builds a binding table of trusted IP-to-MAC address mappings. Dynamic ARP Inspection (DAI) uses this binding table to validate ARP packets, preventing ARP spoofing attacks that can redirect traffic maliciously. Each feature targets a specific Layer 2 threat or misconfiguration. Port Security enforces MAC address limits per port to prevent unauthorized access. BPDU Guard is enabled on edge ports to protect the STP topology by shutting down ports receiving BPDUs, which indicates a possible switch or misconfiguration where none should exist. DHCP Snooping inspects DHCP traffic, allowing only trusted DHCP servers to assign IP addresses and creating a binding table used by DAI. DAI then validates ARP requests and replies against this table, blocking invalid ARP messages that could poison the ARP cache. A frequent exam pitfall is assuming these features are interchangeable or that one feature covers multiple threats. For example, DHCP Snooping does not validate ARP traffic—that is DAI's role. BPDU Guard does not control MAC addresses—that is Port Security's function. Understanding these distinctions is critical for correctly matching each feature to its purpose. In practical networks, these features are often deployed together to provide layered security, but each must be configured and understood individually to be effective and to pass the CCNA exam.
KKey Concepts to Remember
- Port Security restricts the number of MAC addresses learned on a switch port to prevent unauthorized device access.
- BPDU Guard disables a switch port if it receives unexpected BPDUs, protecting the Spanning Tree Protocol topology on edge ports.
- DHCP Snooping filters DHCP messages to block rogue DHCP servers and builds a trusted IP-to-MAC binding table.
- Dynamic ARP Inspection uses DHCP Snooping bindings to validate ARP packets and prevent ARP spoofing attacks.
- Each Layer 2 protection feature addresses a distinct security risk and does not overlap in functionality with the others.
- BPDU Guard is typically enabled on edge ports to prevent accidental or malicious STP topology changes.
- Port Security enforces MAC address limits per port, which helps prevent MAC flooding and unauthorized network access.
- DHCP Snooping and Dynamic ARP Inspection work together to secure IP address assignment and ARP traffic validation in switched networks.
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.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
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 restricts the number of MAC addresses learned on a 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 common exam trap is confusing the purposes of Layer 2 protection features such as Port Security, BPDU Guard, DHCP Snooping, and Dynamic ARP Inspection. Candidates might assume these features overlap or serve the same function, but each addresses a distinct Layer 2 security risk. For example, mistaking BPDU Guard as a MAC address control or DHCP Snooping as ARP validation leads to incorrect answers. The exam often tests your ability to differentiate these features precisely, so mixing their purposes can cause errors.
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.
Discussion
Loading comments…
Sign in to join the discussion.