hardMultiple ChoiceObjective-mapped
220-1201 Practice Question: A network administrator is setting up a new…
A network administrator is setting up a new branch office. The branch router must automatically obtain a public IP address from the ISP, and internal devices must receive private IP addresses from the router. Which combination of network services should be configured on the router?
⚠ Common exam trap
The CompTIA A+ exam often tests the distinction between DHCP client (for obtaining an IP on the WAN) and DHCP server (for assigning IPs on the LAN), and candidates mistakenly think NAT or DNS is required for IP assignment, when in fact NAT is for translation and DNS is for name resolution, not address leasing.
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 client and DHCP server
The branch router needs to obtain a public IP address automatically from the ISP, which requires it to act as a DHCP client on its WAN interface. At the same time, internal devices need private IP addresses, so the router must also act as a DHCP server on its LAN interface, leasing addresses from a private range. Option B correctly combines both roles: DHCP client on the WAN side and DHCP server on the LAN side.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DHCP client and DNS server
Why it's wrong here
This option is incorrect because while a router needs to function as a DHCP client on its WAN interface to obtain a public IP from the ISP, it must act as a DHCP server for internal devices. A DNS server's role is to translate domain names into IP addresses, not to assign IP addresses to clients on the local network. Therefore, including a DNS server instead of a DHCP server for internal IP assignment is a fundamental misunderstanding of network addressing roles.
- ✓
DHCP client and DHCP server
Why this is correct
This option correctly identifies the essential dual roles of a router in a typical branch office setup. On its external (WAN) interface, the router acts as a DHCP client to automatically acquire a public IP address, subnet mask, default gateway, and DNS server information from the Internet Service Provider. Simultaneously, on its internal (LAN) interface, the router functions as a DHCP server, dynamically assigning private IP addresses, subnet masks, and default gateway information to all connected devices within the branch network, simplifying client configuration.
- ✗
DHCP server and NAT
Why it's wrong here
This option is incomplete and therefore incorrect. While a router indeed needs to operate as a DHCP server to assign IP addresses to internal network clients and utilize Network Address Translation (NAT) to allow multiple private IPs to share a single public IP for internet access, it omits a crucial component. The router itself must first obtain its public IP address from the Internet Service Provider (ISP), which is typically accomplished by acting as a DHCP client on its WAN interface. Without this, internet connectivity for the router and the branch network would not be established.
- ✗
DNS server and NAT
Why it's wrong here
This option is incorrect because a DNS server is responsible for resolving domain names to IP addresses, not for assigning IP addresses to network devices. While Network Address Translation (NAT) is a critical function for sharing a single public IP address among multiple private IP addresses on the internal network, it does not handle the initial IP address assignment process. For proper network operation and IP distribution, the router fundamentally requires DHCP client functionality for its WAN interface and DHCP server functionality for its LAN interface.
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Related to this question
Learn chapter
Network Configuration: IP, DNS, DHCP
Key term
WAN
A Wide Area Network (WAN) is a telecommunications network that connects multiple smaller networks, like local area networks, across large geographical distances.
Key term
Public IP address
A globally unique IP address assigned to a device that allows it to communicate directly over the internet.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 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 220-1201 exam.