Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
Which statement correctly describes the purpose of ARP in an IPv4 network?
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
It maps a MAC address to a DNS hostname
Distractor.
B
Best answer
It maps an IPv4 address to a MAC address on the local segment
Correct choice.
C
Distractor review
It advertises routes between routers
Distractor.
D
Distractor review
It negotiates trunk encapsulation between switches
Distractor.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is confusing ARP’s function with DNS or routing protocols. Some candidates mistakenly believe ARP maps MAC addresses to DNS hostnames or advertises routes between routers. This misunderstanding arises because ARP deals with address resolution, but only at the local Layer 2 segment, not with name resolution or routing. Another trap is thinking ARP negotiates trunk encapsulation between switches, which is unrelated. Recognizing that ARP strictly maps IPv4 addresses to MAC addresses on the local network segment helps avoid these pitfalls and select the correct answer confidently.
Technical deep dive
How to think about this question
Address Resolution Protocol (ARP) is a fundamental protocol in IPv4 networking that resolves Layer 3 IP addresses to Layer 2 MAC addresses within a local broadcast domain. When a device wants to communicate with another device on the same local network, it must encapsulate the IP packet inside a frame addressed to the destination MAC address. Since the sender only knows the IPv4 address initially, ARP broadcasts a request to discover the MAC address associated with that IP. The ARP process involves sending a broadcast ARP request packet asking "Who has this IPv4 address?" The device owning that IP responds with its MAC address in an ARP reply. Cisco devices cache these mappings in an ARP table to optimize future communications. This mechanism is crucial for Ethernet networks where MAC addresses are required for frame delivery, and it operates only within the local subnet, not across routers. A common exam trap is confusing ARP with protocols that operate at different layers or serve different purposes, such as DNS for hostname resolution or routing protocols like OSPF for route advertisement. Practically, ARP is essential for local delivery but does not function beyond the local segment. Understanding this distinction helps avoid misinterpreting ARP’s role in IP networking and ensures correct answers on the CCNA exam.
KKey Concepts to Remember
- ARP resolves IPv4 addresses to MAC addresses to enable local Layer 2 frame delivery within the same broadcast domain.
- Cisco devices use ARP requests and replies to dynamically learn and cache IP-to-MAC address mappings in the ARP table.
- ARP operates only within the local subnet and does not resolve addresses across different IP networks or routers.
- ARP is a Layer 2 protocol that supports IPv4 communication by linking Layer 3 IP addresses to Layer 2 MAC addresses.
- Devices send ARP requests as broadcasts to discover MAC addresses when the destination IP is known but the MAC is unknown.
- ARP does not perform hostname resolution, route advertisement, or trunk negotiation, which are handled by other protocols.
- An ARP reply is a unicast message sent directly to the requester containing the MAC address for the requested IPv4 address.
- Understanding ARP’s local scope prevents confusion with routing protocols that operate at Layer 3 or above.
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
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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?
ARP resolves IPv4 addresses to MAC addresses to enable local Layer 2 frame delivery within the same broadcast domain.
What is the correct answer to this question?
The correct answer is: It maps an IPv4 address to a MAC address on the local segment — ARP maps a known IPv4 address to a Layer 2 MAC address on the local network segment. That allows the sender to build the Ethernet frame needed for local delivery.
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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