CCNA Network Infrastructure and Connectivity Practice Question
Network Topology
You are troubleshooting connectivity for a wireless client connected to the home network shown below. The client has obtained an APIPA address (169.254.x.x), indicating DHCP failure. Verify the DHCP server configuration on R1 and correct the issue so that the client receives a valid IP address from the 192.168.1.0/24 subnet.
⚠ Common exam trap
Trap: Candidates often focus on pool configuration (network, default-router, excluded-address) when troubleshooting DHCP failures, but they forget that the DHCP service must be enabled globally with 'service dhcp'. Always check if the service is running before modifying pool parameters.
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
✓
Enable the DHCP service globally using the 'service dhcp' command on R1.
The client obtained an APIPA address (169.254.x.x) because DHCP was not assigning addresses. The DHCP pool is correctly configured, but the global DHCP service must be enabled with the 'service dhcp' command on R1. The excluded-address range (192.168.1.1–192.168.1.10) uses only a small fraction of the /24 subnet, so it is not the issue. Enabling 'service dhcp' allows the router to process DHCP requests and assign addresses from the pool.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Enable the DHCP service globally using the 'service dhcp' command on R1.
Why this is correct
The DHCP service is disabled by default on Cisco routers. The 'service dhcp' command enables the DHCP server and relay agent globally, allowing the router to respond to DHCP requests. Without this command, the router ignores DHCP messages even if pools are configured.
- ✗
Remove the 'ip dhcp excluded-address 192.168.1.1 192.168.1.10' command because it excludes too many addresses.
Why it's wrong here
This is incorrect because excluding 10 addresses from a /24 subnet (254 usable addresses) is not excessive. The exclusion is necessary to reserve addresses for static devices like the router interface. The APIPA issue is not caused by this exclusion.
- ✗
Change the DHCP pool network to 192.168.1.0/24 and add the default-router 192.168.1.1 command.
Why it's wrong here
This change is unnecessary and would not resolve the problem because the DHCP pool on R1 already contains the correct 'network 192.168.1.0 255.255.255.0' and 'default-router 192.168.1.1' statements. The configuration as written is valid and would lease addresses properly if the DHCP service were enabled. Simply rewriting or re-adding these commands does nothing to activate the router's DHCP server engine, which is disabled by default and requires the 'service dhcp' global command. Without that global enable, the client will continue receiving no DHCP replies and will fall back to an APIPA address.
- ✗
Configure the 'ip helper-address' command on the client's VLAN interface to forward DHCP requests to the server.
Why it's wrong here
This is incorrect because the DHCP server is on the same router (R1) as the client's subnet. The 'ip helper-address' command is used to forward DHCP broadcasts to a remote server, which is unnecessary here. The client and server are on the same device.
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.
✓Enable the DHCP service globally using the 'service dhcp' command on R1.Correct answer▾
Why this is correct
The DHCP service is disabled by default on Cisco routers. The 'service dhcp' command enables the DHCP server and relay agent globally, allowing the router to respond to DHCP requests. Without this command, the router ignores DHCP messages even if pools are configured.
✗Remove the 'ip dhcp excluded-address 192.168.1.1 192.168.1.10' command because it excludes too many addresses.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: Excluding 10 addresses does not exhaust the pool; the pool still has 244 addresses available.
Why candidates choose this
Candidates might think that excluding addresses reduces the pool size and could cause exhaustion, but in this case the pool is large enough.
✗Change the DHCP pool network to 192.168.1.0/24 and add the default-router 192.168.1.1 command.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: The pool configuration is already correct; modifying it does not address the disabled DHCP service.
Why candidates choose this
Candidates often assume the pool is misconfigured when clients get APIPA addresses, but the pool commands are correct here.
✗Configure the 'ip helper-address' command on the client's VLAN interface to forward DHCP requests to the server.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: 'ip helper-address' is for DHCP relay across subnets; it is not needed when the server is local.
Why candidates choose this
Candidates may confuse scenarios where the DHCP server is on a different subnet and think relay is always required.
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
Go deeper
Related to this question
Learn chapter
IPv4 Addressing and Address Classes
Key term
Automatic Private Internet Protocol Addressing
A fallback method used by a device to automatically assign itself an IP address when it cannot obtain one from a DHCP server.
Key term
Subnet
A subnet is a logical subdivision of an IP network, created by partitioning a larger network address space using subnet masks.
About these practice questions
Courseiva writes every 200-301 question from scratch — 1,389 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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 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.