N10-009 Network Operations Practice Question
A network administrator wants to implement a protocol to automatically assign IP addresses to devices on the network. Which of the following protocols is used for this purpose?
⚠ Common exam trap
Many exam-takers confuse DNS with DHCP because both are network services that involve IP addresses, but DNS resolves names to addresses while DHCP assigns the addresses themselves.
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
✓
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. This eliminates the need for manual IP configuration, reducing administrative overhead and preventing address conflicts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DNS
Why it's wrong here
DNS maps names to existing addresses; it performs no address assignment. It is tempting because it is the protocol administrators associate with address lookups, and it would be correct if devices needed to resolve hostnames to IP addresses rather than receive configuration automatically.
When this WOULD be correct
A question asking 'Which protocol translates domain names to IP addresses?' or 'Which protocol is used for name resolution?' would make DNS the correct answer.
- ✓
DHCP
Why this is correct
DHCP leases addresses automatically from a configured pool, eliminating manual static assignment. It satisfies the requirement for automatic IP configuration via the DORA process (Discover, Offer, Request, Acknowledge), dynamically allocating addresses, subnet masks, gateways and DNS servers to devices joining the network.
- ✗
ARP
Why it's wrong here
ARP resolves known IPv4 addresses to MAC addresses for local delivery; it never allocates addresses. It is tempting because it is a foundational address-related protocol, and it would be the right answer if the question asked how a host finds a peer's hardware address on the same subnet.
When this WOULD be correct
A question asking 'Which protocol maps a known IP address to a MAC address on a local network?' would have ARP as the correct answer.
- ✗
ICMP
Why it's wrong here
ICMP carries diagnostic and error messages such as echo requests; it has no address-assignment mechanism. It is tempting because administrators use ping to verify connectivity after addressing, but dynamic host configuration is performed by DHCP, which leases addresses, masks, gateways and DNS settings.
When this WOULD be correct
A question asking which protocol is used to test network connectivity or report delivery errors (e.g., 'Which protocol does ping use?') would make ICMP the correct answer.
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.
✓DHCPCorrect answer▾
Why this is correct
DHCP leases addresses automatically from a configured pool, eliminating manual static assignment. It satisfies the requirement for automatic IP configuration via the DORA process (Discover, Offer, Request, Acknowledge), dynamically allocating addresses, subnet masks, gateways and DNS servers to devices joining the network.
✗DNSWrong answer — click to see why▾
Why this is wrong here
DNS resolves domain names to IP addresses, but does not assign IP addresses to devices. The question specifically asks for a protocol that automatically assigns IP addresses, which is DHCP's function.
★ When this WOULD be the correct answer
A question asking 'Which protocol translates domain names to IP addresses?' or 'Which protocol is used for name resolution?' would make DNS the correct answer.
Why candidates choose this
Candidates may confuse DNS with DHCP because both involve IP addresses, or they might think DNS 'assigns' addresses by mapping names to IPs.
✗ARPWrong answer — click to see why▾
Why this is wrong here
ARP (Address Resolution Protocol) is used to resolve IP addresses to MAC addresses, not to automatically assign IP addresses to devices.
★ When this WOULD be the correct answer
A question asking 'Which protocol maps a known IP address to a MAC address on a local network?' would have ARP as the correct answer.
Why candidates choose this
Candidates may confuse ARP with DHCP because both involve IP addresses, but ARP deals with mapping, not assignment.
✗ICMPWrong answer — click to see why▾
Why this is wrong here
ICMP (Internet Control Message Protocol) 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 or report delivery errors (e.g., 'Which protocol does ping use?') would make ICMP the correct answer.
Why candidates choose this
Candidates may confuse ICMP with DHCP because both are network-layer protocols, or they might think ICMP can assign addresses due to its role in network configuration messages.
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
Go deeper
Related to this question
Learn chapter
Configuration Management Database (CMDB)
Key term
Subnet mask
A subnet mask is a 32-bit number that helps a computer or network device determine which part of an IP address identifies the network and which part identifies the host device on that network.
Key term
Fully Qualified Domain Name
A Fully Qualified Domain Name is the complete and unambiguous website or server name that includes the host, domain, and top-level domain, leaving no room for guesswork.
About these practice questions
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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.