Why Can a User Access Internal Resources but Not the Internet?
A user in a small office can access internal network resources by IP address but cannot access any websites by domain name. Other users on the same network can browse the internet without issues. The user's workstation obtains an IP address via DHCP and can successfully ping the default gateway. Which of the following is the MOST likely cause of the issue?
Quick Answer
The answer is an incorrect DNS server address on the workstation. This is correct because the user can access internal resources by IP address and ping the default gateway, proving that network connectivity at Layers 2 and 3 is fully functional; the failure to resolve domain names while other users browse normally isolates the problem to DNS resolution. On the CompTIA A+ Core 1 220-1101 exam, this scenario tests your ability to distinguish between connectivity issues and name resolution failures—a common trap is assuming a faulty gateway or DHCP problem when the real culprit is a misconfigured or missing DNS server address. Remember that DHCP typically provides DNS settings automatically, so if only one workstation is affected, check for manual overrides or a stale DNS entry. A helpful memory tip: “IP works, names fail? DNS is the trail.”
⚠ Common exam trap
Candidates often confuse DNS failure with a general connectivity issue, but the ability to ping the gateway and access resources by IP proves the problem is specific to name resolution, not network reachability.
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
✓
Incorrect DNS server address on the workstation
The user can access internal resources by IP address and ping the default gateway, confirming Layer 2/3 connectivity is intact. The inability to resolve domain names to IP addresses while other users can browse normally points directly to a DNS resolution failure. Since the workstation obtains its IP via DHCP, the most likely cause is that the DHCP server provided an incorrect or no DNS server address, or the workstation's DNS settings were manually misconfigured, preventing name resolution.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Incorrect DNS server address on the workstation
Why this is correct
An incorrect DNS server address prevents the workstation from resolving domain names to IP addresses, while direct IP connectivity still works. Since the user reaches internal resources by IP and pings the gateway, the fault lies in name resolution, not routing or DHCP. Other users are unaffected, confirming a localised misconfiguration.
- ✗
Faulty network cable
Why it's wrong here
A faulty cable would break all connectivity, yet this workstation reaches internal resources by IP and pings the gateway, so the physical link works. It is tempting because cabling is a frequent cause of network faults, and it would be correct if the user had no link light or could not reach the gateway.
- ✗
DHCP scope exhaustion
Why it's wrong here
DHCP scope exhaustion prevents new leases, but this workstation already holds a valid address and pings its gateway, so name resolution fails for another reason. It is tempting because DHCP faults commonly cause connectivity loss, and exhaustion would be correct if multiple clients were failing to obtain addresses at all.
- ✗
Firewall blocking outbound traffic
Why it's wrong here
A firewall blocking outbound traffic would also block the user's IP-based access and gateway pings, which succeed here. The failure is name resolution only, so DNS settings on that workstation are suspect. Firewalls are the right answer when traffic to specific ports or destinations is dropped regardless of naming.
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Same concept, more angles
1 more way this is tested on 220-1101
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A user reports that they can access the internet by typing an IP address (e.g., 8.8.8.8) into their web browser, but they cannot access websites using domain names (e.g., www.example.com). Which of the following network services is MOST likely not functioning correctly?
easy- A.Dynamic Host Configuration Protocol (DHCP)
- B.Hypertext Transfer Protocol (HTTP)
- ✓ C.Domain Name System (DNS)
- D.File Transfer Protocol (FTP)
Why C: The user can reach the internet via IP address but not by domain name, which indicates that the system cannot resolve human-readable names to IP addresses. The Domain Name System (DNS) is the service responsible for this translation, so a failure in DNS resolution is the most likely cause. DHCP, HTTP, and FTP are unrelated to name resolution.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 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 220-1101 exam.