CCNA Network Infrastructure and Connectivity Practice Question
Which two statements about ARP on an IPv4 Ethernet network are correct? (Choose two.)
⚠ Common exam trap
Be careful not to confuse ARP requests with replies, and remember that ARP operates only within a local segment.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
An ARP request is sent as a Layer 2 broadcast.
ARP resolves an IPv4 address to a MAC address on the local segment. ARP requests are broadcast; ARP replies are typically unicast.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
An ARP request is sent as a Layer 2 broadcast.
Why this is correct
An ARP request is a broadcast at Layer 2 because the sender knows the target IPv4 address but not the target MAC address. To reach all devices on the local Ethernet segment, the frame's destination MAC is set to FF:FF:FF:FF:FF:FF, causing switches to flood it out all ports and every host in the VLAN to process it. Only the device configured with the target IPv4 address responds.
- ✓
An ARP reply is normally sent as a unicast frame.
Why this is correct
An ARP reply is unicast because the target host extracts the sender's MAC address from the ARP request's sender hardware address field. Since the requester's MAC is now known, the responder can build an Ethernet frame with that specific MAC as the destination, sending the reply directly back without flooding. This unicast frame traverses the switch as a normal Ethernet frame to the original requester.
- ✗
ARP is used to map IPv6 addresses to MAC addresses.
Why it's wrong here
ARP is exclusively used for IPv4 address resolution over Ethernet. IPv6 hosts and routers rely on Neighbor Discovery Protocol (NDP) implemented as ICMPv6 messages, exchanging Neighbor Solicitation and Neighbor Advertisement packets to map IPv6 addresses to MAC addresses. NDP operation uses solicited-node multicast addresses rather than Layer 2 broadcast, so ARP is not applied to IPv6.
When this WOULD be correct
In a question focused on IPv6 networking, where the task is to identify protocols that map addresses, an option stating that ARP maps IPv6 addresses to MAC addresses could be correct if it was framed in the context of discussing legacy support or compatibility considerations in mixed environments.
- ✗
ARP is forwarded by routers across subnets by default.
Why it's wrong here
ARP messages are not routable between subnets because they are encapsulated directly within Ethernet frames without an IP header or routing layer. Each subnet constitutes a separate broadcast domain, so an ARP request from one VLAN or subnet stays within that local segment. To send traffic across subnets, end hosts forward IP packets to the default gateway's MAC, and the router performs ARP on each destination subnet independently.
When this WOULD be correct
If the question were to ask about protocols that can be forwarded by routers, such as ICMP or routing protocols, then this option could be correct in the context of discussing how certain network protocols behave across subnets.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓An ARP request is sent as a Layer 2 broadcast.Correct answer▾
Why this is correct
An ARP request is a broadcast at Layer 2 because the sender knows the target IPv4 address but not the target MAC address. To reach all devices on the local Ethernet segment, the frame's destination MAC is set to FF:FF:FF:FF:FF:FF, causing switches to flood it out all ports and every host in the VLAN to process it. Only the device configured with the target IPv4 address responds.
✗ARP is used to map IPv6 addresses to MAC addresses.Wrong answer — click to see why▾
Why this is wrong here
ARP is specifically designed for IPv4 networks to map IPv4 addresses to MAC addresses. IPv6 uses Neighbor Discovery Protocol (NDP) with ICMPv6 messages to perform address resolution, not ARP.
★ When this WOULD be the correct answer
In a question focused on IPv6 networking, where the task is to identify protocols that map addresses, an option stating that ARP maps IPv6 addresses to MAC addresses could be correct if it was framed in the context of discussing legacy support or compatibility considerations in mixed environments.
Why candidates choose this
Students may confuse ARP with a general address resolution protocol and assume it works for both IPv4 and IPv6, especially since both involve mapping network-layer addresses to data-link layer addresses.
✗ARP is forwarded by routers across subnets by default.Wrong answer — click to see why▾
Why this is wrong here
ARP operates only within a single broadcast domain (subnet) and is not forwarded by routers. Routers separate broadcast domains and do not forward ARP requests or replies across subnets by default.
★ When this WOULD be the correct answer
If the question were to ask about protocols that can be forwarded by routers, such as ICMP or routing protocols, then this option could be correct in the context of discussing how certain network protocols behave across subnets.
Why candidates choose this
Test-takers might think that because routers forward IP packets, they would also forward ARP messages, not realizing that ARP is a Layer 2 protocol confined to the local network segment.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
Quick reference
Access Control Model Comparison
| Model | Acronym | Who Controls Access? | Best For |
|---|---|---|---|
| Discretionary Access Control | DAC | Resource owner | Small teams, file shares |
| Mandatory Access Control | MAC | System / security labels | Classified govt / military |
| Role-Based Access Control | RBAC | Administrator (via roles) | Enterprise environments |
| Attribute-Based Access Control | ABAC | Policy engine (user + resource attributes) | Fine-grained, dynamic policies |
| Rule-Based Access Control | RuBAC | System rules / ACLs | Firewall rules, network ACLs |
Go deeper
Related to this question
Learn chapter
IPv4 Addressing and Address Classes
Key term
Media Access Control
Media Access Control (MAC) is a sublayer of the Data Link Layer in networking that controls how devices on the same network share access to the physical medium and uniquely identifies each device with a hardware address.
Key term
Internet Protocol
Internet Protocol (IP) is the set of rules that governs how data is addressed, routed, and sent from one device to another across networks, including the internet.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.