N10-009 Networking Concepts Practice Question
Which of the following protocols is used to automatically assign IP addresses to devices on a network?
⚠ Common exam trap
The N10-009 exam often tests the distinction between DHCP (address assignment) and DNS (name resolution), leading candidates to confuse the two because both are essential for network communication, but only DHCP handles automatic IP configuration.
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
✓
B) DHCP
DHCP (Dynamic Host Configuration Protocol) is the correct answer because it is specifically designed to automatically assign IP addresses and other network configuration parameters (such as subnet mask, default gateway, and DNS servers) to devices on a network. When a client device connects, it sends a DHCP Discover broadcast, and the DHCP server responds with an Offer, followed by a Request and Acknowledgment (DORA process), enabling plug-and-play connectivity.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A) DNS
Why it's wrong here
DNS (Domain Name System) acts as the internet's distributed directory service, translating human-readable domain names (e.g., www.example.com) into numerical IP addresses (e.g., 192.0.2.1) that computers use to identify and locate resources on the network. While crucial for network communication by providing addresses, DNS's role is purely one of name-to-address translation and resolution. It does not participate in the dynamic assignment or distribution of IP addresses to client devices.
When this WOULD be correct
A question asking 'Which protocol translates domain names to IP addresses?' would have DNS as the correct answer.
- ✓
B) DHCP
Why this is correct
DHCP (Dynamic Host Configuration Protocol) is a foundational network protocol specifically designed to dynamically assign IP addresses and other critical network configuration parameters, such as subnet masks, default gateways, and DNS server addresses, to devices on an IP network. This automation significantly reduces administrative overhead, prevents IP address conflicts, and ensures efficient reuse of addresses as devices connect and disconnect from the network. When a client boots up, it initiates a process to obtain an IP lease from a DHCP server.
- ✗
C) ARP
Why it's wrong here
ARP (Address Resolution Protocol) is a Layer 2 protocol that performs the essential function of mapping a known IP address to its corresponding physical MAC (Media Access Control) address within a local network segment. When a device needs to send data to another device on the same subnet and only knows its IP address, ARP is used to discover the necessary MAC address for frame delivery. ARP is solely for address resolution and does not assign or distribute IP addresses to network devices.
When this WOULD be correct
ARP would be the correct answer for a question like: 'Which protocol maps a known IP address to a MAC address on a local network?'
- ✗
D) ICMP
Why it's wrong here
ICMP (Internet Control Message Protocol) is a network layer protocol primarily utilized for sending control messages, error reports, and operational information between network devices. It is fundamental for network diagnostics and troubleshooting tools, such as `ping` (which uses ICMP echo requests and replies to test connectivity) and `traceroute`. ICMP's function is limited to reporting network conditions and errors, not to the allocation or assignment of IP addresses or other network configuration parameters to hosts.
When this WOULD be correct
A question asking 'Which protocol is used to test network connectivity between two hosts?' would make ICMP correct, as it is the foundation of ping and traceroute utilities.
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 N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓B) DHCPCorrect answer▾
Why this is correct
DHCP (Dynamic Host Configuration Protocol) is a foundational network protocol specifically designed to dynamically assign IP addresses and other critical network configuration parameters, such as subnet masks, default gateways, and DNS server addresses, to devices on an IP network. This automation significantly reduces administrative overhead, prevents IP address conflicts, and ensures efficient reuse of addresses as devices connect and disconnect from the network. When a client boots up, it initiates a process to obtain an IP lease from a DHCP server.
✗A) DNSWrong answer — click to see why▾
Why this is wrong here
DNS resolves domain names to IP addresses, but does not automatically assign IP addresses to devices.
★ When this WOULD be the correct answer
A question asking 'Which protocol translates domain names to IP addresses?' would have DNS as the correct answer.
Why candidates choose this
Candidates may confuse DNS with DHCP because both are essential network services and involve IP addresses, leading to a mix-up of their functions.
✗C) ARPWrong answer — click to see why▾
Why this is wrong here
ARP (Address Resolution Protocol) is used to resolve IP addresses to MAC addresses on a local network, not to automatically assign IP addresses.
★ When this WOULD be the correct answer
ARP would be the correct answer for a question like: 'Which protocol maps a known IP address to a MAC address on a local network?'
Why candidates choose this
Candidates may confuse ARP with DHCP because both involve IP addresses and network configuration, leading to a mistaken association with address assignment.
✗D) ICMPWrong answer — click to see why▾
Why this is wrong here
ICMP is used for error reporting and diagnostic functions (e.g., ping, traceroute), not for automatic IP address assignment.
★ When this WOULD be the correct answer
A question asking 'Which protocol is used to test network connectivity between two hosts?' would make ICMP correct, as it is the foundation of ping and traceroute utilities.
Why candidates choose this
Candidates may confuse ICMP with DHCP because both involve network layer communication, or they might think ICMP handles address resolution due to its role in network troubleshooting.
Analysis generated from the official N10-009blueprint 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
IPv4 Address Class Summary
| Class | First Octet Range | Default Mask | Networks | Hosts per Network |
|---|---|---|---|---|
| A | 1–126 | /8 (255.0.0.0) | 126 | 16,777,214 |
| B | 128–191 | /16 (255.255.0.0) | 16,384 | 65,534 |
| C | 192–223 | /24 (255.255.255.0) | 2,097,152 | 254 |
| D | 224–239 | N/A | Multicast groups | — |
| E | 240–255 | N/A | Reserved / experimental | — |
127.x.x.x is reserved for loopback. Modern networks use CIDR (classless) rather than classful addressing.
Go deeper
Related to this question
Learn chapter
Interior vs Exterior Routing Protocols
Key term
DHCP server
A DHCP server is a network device or service that automatically assigns IP addresses and other network configuration parameters to devices on a network, eliminating the need for manual configuration.
Key term
Default gateway
A default gateway is a network device, typically a router, that acts as the exit point for traffic from a local network to other networks, including the internet.
About these practice questions
This N10-009 question is part of Courseiva's 464-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This N10-009 practice question is part of Courseiva's free CompTIA 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 N10-009 exam.